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NC1038: Methods to Increase Reproductive Efficiency in Cattle (NC1006)

Annual/Termination Reports (SAES-422): [09/09/2009] [09/15/2009] [09/28/2010] [08/24/2011] [09/17/2012]

Date of Annual Report: 09/09/2009

Report Information:
  • Annual Meeting Dates: 08/12/09 to 08/21/09
  • Period the Report Covers: 10/2008 to 09/2009

    • Participants:
    Brief Summary of Minutes of Annual Meeting:
    Thursday, August 20th, 2009

    8:00 - 8:30: Introductions and Registration Room was $150. Registration is $10 per person.

    Dairy collaborative projects: No dairy collaborative project was done last year. Discuss collaborative efforts tomorrow.

    Station reports:

    Kansas State University (Stevenson): Use of hCG to induce accessory CL during early embryonic development: Embryo transfer recipients w and w/o 1000 IU hCG, CL were counted on d 30 and 60 of pregnancy and pregnancy diagnosis occurred. Although P4 concentrations and accessory CL numbers were greater on d 30 and 60 with hCG treatment, pregnancy rates were numerically greater (not significant) on d 30 or 60. No differences in pregnancy loss. These were just in the pregnant cows on d 30 and 60. Note that the hCG was only given to multiparous recipients that had a CL to begin with.

    What is the hCG availability? It is always on back order& still extracting from placentas. Is there a threat to the market? Because of the athletes?? What is the future? Not known what the antibody response is. If you make it up, make sure you refrigerate and use in 24 hr or freeze it.

    CIDR after breeding to increase pregnancy? No increase in circulating P4 but perhaps there is an increase in the endometrial P4 content. hCG may be better as you keep the P4 around longer than when you pull the CIDR.

    Exp 2. Resynch ovulation in dairy cattle with unknown pregnancy status; See design in KSU report. If GnRH is given 7 d before a pregnancy check on d 39 after AI, then there is a greater pregnancy response to GnRH compared with saline. In contrast, this is not the case if GnRH is given 7 d before a not pregnant diagnosis on d 32 after AI.

    Exp 3: Induction of luteolysis before TAI after Estrumate or Lutalyse: no difference in conception rate; interesting split of the cattle in their P4 profiles from hr 0, 48, 72 after PGF administration.

    At AI: Timed AI only (33.1) < estrus only (41.1) < TAI + estrus (52.8).

    Exp 4: Use of eCG to stimulate pregnancy outcome in suckled beef cattle: could increase E2 by eCG administration after dominant follicle selection  potentially by the FSH activity of eCG binding to granulosa cell FSH receptors. So far, no differences in pregnancy rates are detected in beef cattle. A dairy project is near completion.

    Discussion: What percentage of eCG has LH activity? Need to find out.

    University of Wisconsin-Madison (Fricke): Experiment 1. Effect of increasing GnRH and PGF dose during double-Ovsynch on fertility of lactating dairy cows at first postpartum TAI.

    In primiparous cows, double Ovsynch has a greater response than Presych-Ovsynch. In a comparison of Long vs Short schedule: long schedule cows have GnRH 7 d apart; thought is to have more P4; in the short schedule there is low P4; Short grouplow P4 vs long group; ovulation to last GnRHno difference in synchrony. If you look at double ovulations there is an increase in short schedule animals vs long; conception was decreased and there was an increase in embryonic loss in the short termbut there were more ovulations&. Best to start a synch protocol in a high P4 environment.

    Dose trial (2 x 2 factorial: 2 cc vs 4cc GnRH at the first GnRH injection and PGF 2 cc vs 3 cc (estrumate) at the breeding Ovsynch): no difference statistically.

    2nd comparision: 2cc GnRH + 2cc PGF vs 4cc GnRH + 3cc PGF: no differences Question to the group: do we use more number of cows at one location or fewer cows at more locations.

    Discussion: Our role as a committee is to do these types of experiments with the only output being pregnancy rate. To do more intensive measurements is for a one site, more in depth experiment.

    ReSynch: testing the interval breeding 42 vs 49 days. Pregnancy rates on d 29 and 74: increased in the double Oovsych vs d32 Resynch protocol. Pregnancy loss is not different; double Ovsynch increased the presence of CL at time of first GnRH injection. P4 is increased in the double Ovsynch protocol at the time of first GnRH injection.

    University of Kentucky (Silvia): A comparison of physiological and endocrine parameters during the periestrual period in lactating dairy cows that did and did not conceive. Measured the difference in LH and E2, dominant follicular size, in cows that did and did not conceive. There were no differences. There were 3 NP cows had a peak of LH before the onset of estrus. So interesting point that some cows may be ovulating before onset of estrus?

    USDA-MARC (Cushman):

    Size of the ovarian reserve and how this impacts fertility: animals with less than 100,000 oocytes

    Reproductive tract scores and ovarian reserve; lower follicle cows have smaller ovaries.

    Antral follicle counts (AFC): low AFC has smaller ovary sizes; birth wt is smaller and percent pregnant is lower. Heifers who are smaller at birth have a decreased AFC.

    Reproductive tract score was lower in the lower AFC heifers.

    High AFC heifers have increased progesterone during the cycle ; larger endometrial area as well.

    Stage of the cycle does not really affect the AFC.

    Perhaps the increase in fertility in the offspring from the protein supplementation in cows of Funston can correlate with the AFC? Cushman is looking at this with some experiments being carried on at MARC.

    GH receptor deficient Brahman, they have fewer antral follicles; decreased serum IGF-1, and decreased serum progesterone.

    Pregnancy rates decline at 6 yr of age. Serum IGF-I decreases with the increasing age.

    Hypothesis: Clock gene (Period 1) and StAR will be decreased in old vs young cows (< and > 6 yrs).

    Age impacts AFC, CL weight, P4 (younger is better).

    Period 1 is increased in young cows. Star and HSD are not different.

    Comments from Administrative Advisor, Bill Ravlin, CSREES Representative, Adele Turzillo.

    Bill Ravlin: Midterm review must be submitted to NCRA DirectorsOffice NLT Feb 15, 2010 so it can be reviewed for the March 2010 meeting.

    Need to make sure that the collaborations are documented. Joint projects are very useful for the review. Provide a funding summary for the review to provide leverage for the continuation of the project. Report the value of the animals that we are using. Contributions for these projects, also grants and contracts. Bill will email us to get the information he needs to complete this report.

    Make sure that you provide good impact statements. Provide information to OMB by CRIS forms and impact statements. Output is papers, talks, etc.; impact answers the question Who cares. Impacts on the mission; impacts on the discipline; impacts on the environment, what are the social impacts The next re-write should include that we are training the next round of animal scientists.

    Adele Turzillo: CSREES will cease in 40 daysnow will be called NIFANational Institute of Food Agriculture. October 1st. Director will be presidentially appointed. There will be a transition team. There has been input by the stakeholders for the running of the new institute. FY2010 funding highlights: in the handout.

    Competitive programs: NRI=AFRI; for the non-integrated program: 60% fundamental 30% must be done by multidisciplinary teams; 40% applied research. Integrated solutions for animal agriculture program: need a letter of intent. These are reviewed internally.

    Adele reviews Hatch proposals.2 common reasons for not signing off: if your hatch project is related to a multi-state project, the objectives must match. The other has to have an approved IACUC approval.

    University of Florida (Lamb): in November or December would like to have a Summit for the integrated program and for the research proposal. Project 1. Administration of hCG 7 d after TAI of suckled beef cows hCG increased pregnancy rates.

    Lamb is recommending that you use it: more CL, more total CL volume on d 14, and more progesterone in circulation. Impacts of handling cattle with synch protocols and keeping them consistent in studies was discussed.

    Project 2: Effects of 66 hr temporary calf removal on calf wt gain and pregnancy rates between CIDR removal and TAI in estrous synchronized suckled beef cows exposed to the CO-Synch + CIDR protocol.

    Increased pregnancy rates by 7% (not statistically different)weigh the calvesthey do not catch back up  so it is a problem with the calf or with the dams mammary gland. Range in calf age?

    Experiment 3: Embryo quality from superovulated cows treated with NHNFIimmune product. Immune product bolus + FSH (n=35-37); increased the percentage of grade 1 embryos; doesnt know what this product is&

    Experiment 4: Effects of supplemental progesterone during culture on the development, metabolism, and numbers of cells of bovine embryos produced by IVM, IVF and culture.

    Progesterone did not effect the development of the embryos. Are there progesterone receptors on the conceptus?

    University of Illinois (Krisher): Kesler is retiring Sept 15th

    Maternal age alters fetal and placental development and the expression of methylated genes. Old mice appear to have impaired regulation of genes necessary for appropriate placental and fetal development. Was this their first pregnancy?

    In porcine ovaries, leptin alone in IVF/IVM procedures results in no differences. Absence of glucose has a negative effect on maturation of the oocyte. Depending upon the amount of glucose in the media, leptin appears to influence maturation.

    Microarray work: glutaredoxin pathway genes are expressed in porcine oocytes--

    Unpublished work: Model for PCOS with the Ossabaw swine: When fed a diet that induces metabolic syndrome, these pigs had increased triglycerides, cholesterol, and androstendione. May be a good model for this important biomedical problem.

    Talked about these cool embryo chambers, where communication between embryos could be investigated.

    South Dakota State University (Perry): Project 1: Influencing initiating luteal regression just before GnRH initiation of a new follicular wave and synchrony of estrus (development of the PG-CIDR protocol). There was a shift in the distribution of estrus in virgin beef heifers following PGFthose on the PG-CIDR exhibited estrus ~6 h sooner than those with just the CIDR. There is a decreased variation in the concentrations of circulating P4 in the PG-CIDR vs CIDR heifers. The PG-CIDR protocol was also compared with the 5-d CIDR protocol. George demonstrated an overall increased in pregnancy rates with the PG-CIDR vs 5-d CIDR.

    Project 2: Uterine biopsy worklooking at mRNA expression in high E2 and low E2 cattle. The relative gene expression of different factors was determined on different days of the estrous cycle from the endometrium. If there was a difference in the factor of interest between the high and low E2 cows, it appeared at estrus (d 0).

    Question raised: Are you sure you are getting caruncular tissue? There is variation between caruncular and intercaruncular tissue?

    Project 3: Influence of blood sulfate concentrations on uterine pH. Feeding distillers grains increases sulfur concentrations. However, there is also an increase with higher protein and high sulfur diets. A protein- sulfur study needs to be done to tease apart some of the differences found. Collaboration between SDSU and NDSU is being discussed.

    North Dakota State University (Vonnahme): Project 1: Does linseed meal (which contains high phytoestrogens levels) during the later part of gestation influence growth and puberty of the offspring? It does not seem to be a problem. This bi-product can be used as a supplement during pregnancy.

    Project 2: Short term oilseed supplementation around breeding and its impacts on pregnancy rates. We did not find any positive effects on pregnancy rates with either a whole soybean or flaxseed supplementation. Interestingly, the number of heifers that exhibited estrus activity (by HeatWatch) was increased in the fat supplementation groups compared with the Control group (no fat added in the diet).

    Project 3: Restriction during pregnancy in multiparous cows seems to affect the vascular reactivity of the placental vessels more after the cattle have been realimented. This suggests that there is perhaps some placental programming that may impact future growth of the calf.

    Friday, August 21st, 2009

    8:00 - 8:30: Business Meeting: Election of Secretary and selection of meeting time/place for 2010 2010 Meeting:

    Anchorage, Alaska on the 2nd and 3rd-- preceding the 8th Ruminant Reproduction Symposium (Hilton Hotel) in September 3rd (welcoming reception) through the 7, 2010.

    Chair: Vonnahme

    Secretary: Bridges

    Member at Large: Rick Funston with the meeting in North Platte

    Next on the list: Jamie Larson

    Purdue (Bridges): Project 1: Investigation of an alternative method to synchronize estrus in beef heifers; wanting to reduce progesterone during the follicular wave as this may increase fertility in beef heifers. A multi-location trial was conducted comparing the CIDR 5d, CIDR-7d and a modified protocol. Pregnancy rate to CIDR-7d was reduced compared with the 5 d and modified protocol. No ovulation data was collected.

    Project 2: Impact of progesterone concentrations during the development of the follicular wave on the dominant follicule. In the Low P4 group, there was an increase in follicular size at CIDR removal, but not at ovulation.

    Project 3: Use of a double dose of PGF in the 5-d CO-Synch + CIDR program in beef cowsPGF was given either 2 or 8 h apart. No difference in pregnancy rate. So potentially we can run cows through the chute once

    Discussion of the group: What is the difference between cows and heifers: Lactating cow is breathing moremore passage through the lungsPGF metabolism Timing of ovulation is slow in really old cows

    BCS and wt of heifers

    Double ovulation?

    Ovulation to GnRH is greater in the cow than to heifer

    2 injections will limit the 5 d CIDRdoesnt seem to be the case. More resistance to fall breeders due to decreasing day light

    Additional project Allen is working on: Evaluation of luteal blood flow following PGF administration:

    How long do accessory CL liveif the heifers/cows do not get pregnant? So are accessory less responsive to endogenous PGF? Papers by Tiponin with dairy females, giving GnRH late in the cycle and they do unpredictable things.

    GnRH and PGF at the same time, get a fall of P4 Fields with Brahma heifers do not respond

    The timing between the normal and accessory CLthey regress earlier than a normal CLthey can regresss earlier than a normal CL (spontaneous).

    The composition of the CL may be different depending upon the reagent used to induce ovulation.

    Low P4 may reset the uterine environment.

    Accessory CL have a cavityblood vessels terminate near the periphery of the CL

    20% of cows that do not get bred probably have this accessory CL phenomenon. Economics behind AI- do these 20% not get pregnant until the accessory CL regressso this may be phenomenon may also be the case in natural bred cows&. What is the physiology of the timed AI cows& how does this work?

    The Ohio State University (Ottobre) Project 1: Vitamin C and the CL: Ascorbic acid is a free radical scavenger. PGF decreases vitamin C.

    Does oxidative stress impact the timing on the regression of the dominant follicle?

    Why does the CL have so much Vitamin Cit is also really high in the adrenal gland&. During steroidogenesisit may be important for this process. In the pig, release of vit C into the circulation occurs upon regression. Venous levels were not different in the sheep as Joe has seen in the pig.

    Vit C is not high in the folliclelevels are far higher& Citrus pulp has a component that decreases p4 catabolism

    University of Nebraska (Funston): Projects are to investigate the role of different production systems on heifer adaptability and potential longevity in the herd.

    Supplementation with DDGS; Varibility of DDGS for these supplementation trials and for producers. Low input systems for the heifer As of today, there are no negative effects of these low input systems

    George data confirms Ricks data

    Change in nutritiondoes this influence embryonic loss? Or retard embryonic development?

    Gain at different increments in heifers life: gain from weaning to breeding is not significant; her gain from birth to 2 mo and 2 to 6 months& these are pubertal.

    Perhaps this programs the gonadotropin axis? Pat Hoffman& Chung Parks datamaybe more milk related Wiltbank: for birth to weaning is most important for the onset of puberty

    Iowa State University (Anderson): GH secretion in cell culturepituitary gland challenged with the GH secretagogue (692585); looking histologically with EM and IHCGH with immunogold antibody. No release of vesicle contentgold is released. Those with complete release have no gold left. There is a track to the membranethe amount of GH released is variable.

    The porosome--the application in biology and medicine on the release of GH in different tissues.

    Collin ScanesVP of research in University of Wisconsin Milwakee; Looking at chicken somatotropeslook at this in the USDA impact sitepicked up for a story there.

    Matt Wilson and Lloyd had a  managing prenatal development to enhance livestock productivity.

    Working with Matt Lucy and use of RU486 in progesterone receptors in pigs during early pregnancy.

    Discussion on collaborative projects: How many people will attend Lambs integrated and research proposal: everyone was; an economist is already selected. Need a Rural sociologist for the project.

    Look into your university system regarding rural sociologist. Lamb will email everyone the time that would work best for the meeting.

    11:30 Adjourn

    Accomplishments:
    Accomplishments/Outputs:

    Objective 1: To develop breeding programs to maximize pregnancy rates.

    Florida:

    Administration of 1,000 IU of hCG to suckled beef cows 7 days after insemination increased volume of luteal tissue on day 14 and concentrations of progesterone on day 14 and 23 after timed-AI. Treatment with hCG tended to increase pregnancy rates at 5 locations from 1.1 to 27 percentage points compared with saline.

    For cows exposed to temporary weaning, no difference in pregnancy rates were noted compared to controls. However, calf weight gain was greater for control than calves exposed to temporary calf removal.

    The number of transferable embryos collected per flush was not increased in cows treated with Nutrition Horizons Factor Immune product; however, the quality of transferable embryos was improved after embryo donor cows received Nutrition Horizons Factor Immune product prior to embryo collection.

    Administration of progesterone at 1 ng/mL or 100 ng/mL during the culture of in vitro produced embryos may have slight affects on embryo characteristics; however, there appears to be no advantage of supplementing progesterone to in vitro embryos to enhance cleavage rates, development to blastocysts, and metabolic characteristics.

    Illinois:

    In a 5 day CO-Synch protocol the addition of a CIDR improved pregnancy rates and calving rates.

    Indiana (Purdue):

    Conception to AI was greater in heifers synchronized with a modified 7 day Select Synch or a 5 day Select Synch Protocol as compared to the standard 7 day Select Synch Protocol.

    Reducing the concentration of progesterone during the development of the follicular wave resulted in a slight increase in size of the dominant follicle during proestrus, but did not impact size of the dominant follicle at ovulation.

    Kansas:

    Injection of hCG on d 7 post-estrus (at the time of embryo transfer) induced ovulation and increased concentrations of progesterone pregnant recipient beef cows. Although insufficient replication of treatments prevented detection of greater pregnancy rates after hCG treatment, a numerically (6.4 percentage points or a 11.5% increase) greater proportion of recipients were pregnant after hCG treatment.

    When ultrasound is used to diagnose pregnancies at earlier post-AI intervals (d 29 to 35), reinitiating a resynchronized ovulation program with a GnRH injection in cows of unknown pregnancy status 7 d before a not-pregnant diagnosis seems to be contraindicated because resulting pregnancies per AI were not improved. For herds in which pregnancy diagnosis is made at a later post-AI interval (d 36 to 42), either by transrectal ultrasound or palpation, initiating the resynchronization program requires GnRH to improve resulting fixed-time pregnancies per AI. Changing the timing of the second GnRH to 56 h after PGF2a and inseminating 16 h later (72 h post-PGF2a) clearly improved fixed-time pregnancies per AI compared with concurrent insemination and GnRH treatment at 72 h. Because treating pregnant cows with GnRH 7 d before pregnancy status is known did not negatively affect subsequent pregnancy maintenance assessed 6 wk later, its use to initiate resynchronization 7 d before cows are diagnosed not pregnant after d 35 since last AI is justified.

    Administration of FSH-like activity of eCG failed to improve fixed-time AI pregnancy rates in suckled beef cattle, and may have had a negative effect.

    Nebraska (ARS-USDA U.S. Meat Animal Research Center):

    We have identified antral follicle counts as a phenotype that when combined with the traditional reproductive tract score improves the diagnostic capability for predicting heifer fertility immediately before the breeding season. Because age at puberty, heifer pregnancy rate, and reproductive longevity are genetically correlated these should be highly profitable replacement heifers. Ultrasonography is currently the most cost effective method for identifying heifers with low antral follicle counts.

    Nebraska (UNL West Central Research and Extension Center):

    Compared with steers from non-supplemented cows, steers from protein supplemented cows had greater marbling scores and a greater proportion graded USDA Choice or greater. Protein supplementation of dams increased the value of calves at weaning and of steers at slaughter regardless of winter grazing treatment. Calf birth and weaning weight were increased by grazing corn residue during the winter. Calf weaning BW was increased by protein supplementation of the dam if the dam grazed on winter range. Compared with steers from non-supplemented cows, steer progeny from protein supplemented cows had a greater quality grade with no effect on yield grade. These data support a late gestation dam nutrition effect on calf production via fetal programming.

    Wet corn gluten feed in postpartum primiparous beef cow diets improved cow ADG prior to breeding and dried distillers grains plus solubles increased 205 day weaning BW of female offspring. Both dried distillers grains plus solubles and wet corn gluten feed are acceptable supplements for primiparous cows and may improve beef production sustainability.

    Supplemental nutrition during the periconceptual period was of limited value. However, injection of PGF in a 25 d breeding season improves synchrony of calving and increases steer calf weaning BW and value.

    Development grazing corn residue reduces ADG before breeding without sacrificing final pregnancy rate. Development grazing on winter range increases milk production, but does not increase weaning BW. Grazing corn residue during heifer development reduces cost compared to the dry lot. Grazing corn residue or winter range is suitable for heifer development at similar cost.

    Heifers grazing corn residue post weaning gain more and are more efficient while grazing CR as pregnant heifers. The benefit of grazing corn residue post weaning is most pronounced compared to heifers developed in the dry lot. These data provide evidence of an adaptive response to grazing low quality forages and may be beneficial in the critical period leading up to the first calving season.

    Estrous synchronization with a single injection of prostaglandin F2± resulted in more cows giving birth earlier, even though the breeding season was 15 d shorter. Calves born earlier in the season are heavier at weaning and produce a heavier, more valuable carcass.

    South Dakota:

    More heifers treated with PG-CIDR (P = 0.06) initiated a new follicular wave at the initiation of treatment compared to CIDR treated heifers.

    Interval to estrus following CIDR removal did not differ between treatments (55.7 ± 2.1 and 63.3 ± 5.1 h, respectively); however, the variance for the interval to estrus was reduced (P < 0.01) in PG-CIDR (46.3) treated heifers compared to CIDR (291.6) heifers.

    There was a treatment time and treatment by time interaction (P = 0.005) on circulating concentrations of progesterone.

    There was a treatment by time interaction on concentrations of estradiol. Estradiol was increased at time of CIDR insertion among PG-CIDR treated heifers compared to CIDR heifers.

    Overall pregnancy success was 51% (94/184) for the 5-day CIDR and 62% (131/212) for the PG-CIDR group.

    Wisconsin:

    Increasing the dose of prostaglandin and/or GnRH analogs used during the Breeding Ovsynch of Double Ovsynch did not statistically affect fertility in lactating dairy cows.

    Double Ovsynch used as a resynchronization strategy improved fertility compared to a 32-d Resynch strategy but resulted in a 7 d increase in the interval between TAI.

    Reducing dry period length appeared to increase reproductive efficiency in older cows perhaps by shortening time to first ovulation, reducing numbers of anovular cows, and improving fertility.

    Objective 2: To characterize physiological mechanisms that regulate ovarian and uterine functions.

    Illinois:

    We have determined that cellular redox pathways play a major role in porcine oocyte developmental competence.

    We have demonstrated that the Ossabaw mini-pig displays many of the diagnostic symptoms of polycystic ovary syndrome (PCOS) characterized in women, and thus may be an excellent animal model for study of the disease. Currently, no animal model exists that exemplifies both the reproductive and metabolic aspects of the disease.

    Iowa:

    The expression of peroxisome proliferator-activated receptor (PPAR³) has been detected in ovarian tissue from cattle, indicating that this transcription factor may modulate gene expression allowing for the cyclic functioning of the ovary. The high expression of PPAR³ affects progesterone secretion and luteal formation. Increased ovarian progesterone secretion in cattle will prevent lost income associated with reproductive losses for the producer and increased profitability.

    In a complementary series of three animal experiments, genes and pathways important in feed intake and feed efficiency in growing pigs were investigated by evaluating differences in gene expression in pigs that differed in residual feed intake or genotype for the Melanocortin 4 receptor gene (MC4R), or that were subjected to feed restriction, fasting, or ICV injection with an MC4R agonist (MSH). No conclusive differences were identified between pigs that differed in residual feed intake or MC4R genotype. The lipid metabolic pathway was, however, found to be involved in both pigs that differed in residual feed intake and pigs subjected to feed restriction. Strong transcriptional responses to fasting and feed restriction were identified in liver and fat, and corroborated by changes in blood metabolites. Pathway analyses indicated a switch to a conservation mode of energy by down-regulating lipid and steroid synthesis in both tissues. Fasting increased expression of genes involved in glucose sparing pathways in liver, and in extracellular matrix pathways in fat. Feed restriction altered expression of immune response genes and of cell cycle/apoptotosis pathways. Involvement of transcription factors such as PPARG, SREBF1 and CEBPA in regulating expression of genes that responded to fasting or feed restriction was confirmed and several additional transcription factors that are not known to be involved in energy homeostatic responses, such as ESR1, were implicated. Strong transcriptional responses to injection with MSH were identified. In the hypothalamus, genes involved in cell communication, nucleotide metabolism, and signal transduction were down-regulated, while in both the liver and fat, energy-intensive biosynthetic and catabolic processes were down-regulated in response to MSH, suggesting a metabolic shift toward energy conservation. To enable statistical analysis of the above data, several statistical methods were developed and applied, including methods for joint analysis of the data from related experiments, comparison of alternate normalization methods, model choice and comparison, estimation of the underlying number of genes that are differentially expressed, uncovering hidden design variables, and joint analysis of groups of genes. In addition, methods for design of microarray experiments that consider the impact of micro-array processing variables were developed. An open-source web application, ANEXdb (http://www.anexdb.org), was developed that supports integrated access to novel data bases with microarray expression (ExpressDB) and EST annotation (AnnotDB) data. AnnotDB houses a novel assembly of ~2.5 million porcine expressed sequences that has been annotated and mapped to probes on the Affymetrix porcine microarray. The porcine expressed sequences were also mined to identify over 2 million SNPs, along with many deletions and insertions. Results of these studies were presented at several national and international scientific conferences, including an invited presentation at the American Association of Animal Science Midwest meeting. Several scientific papers have been published and are in preparation.

    Kentucky:

    We failed to detect any dramatic difference in endocrine or other physiological parameters between lactating dairy cows that conceived and those that did not. This included differences in follicle size at ovulation, duration of estrus, the maximum concentration of estradiol or LH achieved during the periestrual period. There was a tendency for the onset of estrus to occur late relative to the time of the LH surge in cows that failed to conceive. This would lead to a delay insemination relative to the time of ovulation; however, this effect was relatively modest and seems unlikely to be an adequate explanation for the failure to conceive.

    Nebraska (ARS-USDA U.S. Meat Animal Research Center):

    Reproductive ageing in beef cows is associated with decreased follicle numbers, decreased serum progesterone concentrations, and changes in ovarian gene expression. Genes associated with ovarian ageing are candidates as genetic markers of stayability in beef cows.

    North Dakota:

    Supplementation of linseed meal during late gestation does not appear to impact growth rate in calves or the onset of puberty in heifer calves.

    Conception to a timed artificial insemination program was not enhanced when oilseeds were fed to primiparous beef heifers during estrous synchronization and continuing past day 18 relative to artificial insemination.

    Data suggest that fetal and maternal portions of the placenta respond differently to restriction and realimentation. Moreover, we may be affecting the development of either vascular smooth muscle cell development in the caruncular bed, or its ability to constrict in the presence of adrenergic or angiotensin agents. Further work needs to be done to confirm the ability of the placenta to alter blood flow during bouts of nutrient restriction.

    Ohio:

    There is no evidence to suggest that the sheep contains a truncated version of SCVT2 as observed in the human. There is evidence that the 3' end of SVCT2 is approximately 1800 base pairs, however sequencing is needed.

    South Dakota:

    Concentrations of estradiol on day 0 and 5 were greater in highE2 cows compared to lowE2 cows but did not differ between treatments on days 10 and 16.

    Concentrations of progesterone did not differ between treatments on day 0 or 10 but tended to be and were greater in highE2 compared to lowE2 cows.

    Expression of estrogen receptor ± decreased from day 5 to day 10 in highE2 cows but was similar in lowE2 cows.

    Expression of estrogen receptor ² did not differ between days 5 and 10 or between treatments.

    Expression of progesterone receptor was greater on day 5 compared to day 10 but did not differ between treatments.

    Oxytocin receptor expression decreased from day 5 to 10 in both treatments.

    Expression was greater on day 5 in highE2 cows compared to lowE2 cows but did not differ on day 10.

    Expression of uterine milk protein precursor, period 1, and inhibin bA did not differ between treatments or between days 5 and 10.

    Expression of proenkephalin did not differ between treatments on day 5 but expression increased from day 5 to 10 in highE2 cows but not in lowE2 cows.

    Blood urea nitrogen concentrations increased in animals fed the higher protein high sulfur diet but were not different between the animals fed the low and medium sulfur diets.

    Sulfate concentrations increased from d 7 to 11 in LOW, MED, and HIGH heifers.

    Uterine pH tended to decrease among LOW heifers, and decreased from d 7 to 11 in MED and HIGH.

    There was a significant positive correlation between time and sulfate concentrations.

    There was a significant negative correlation between sulfate concentrations and uterine pH.

    Impact Statements:
    1. Administration of hCG 7 days after timed-AI in beef cows increased fertility by 6.3%. Therefore, the potential exists for use of hCG in estrus synchronization protocols to enhance fertility of females exposed to fixed-time AI and result in a greater proportion of AI sired calves. In addition, improvement of fertility will generate more interest by beef producers to utilize fixed-time AI estrus synchronization systems, thus enhancing the overall use of AI.
    2. NC-1038 scientists have proven that by increasing the percentage of grade 1 embryos in an embryo transfer operation will result in a greater proportion of embryos conceiving after transfer and will enhance overall success of embryo transfer programs.
    3. By having an increased understanding of the mechanisms that impart oocyte competence will allow NC-1038 researchers to design estrous synchronization and super stimulation protocols to best support high oocyte quality, resulting in increased reproductive efficiency. Developing more effective estrous control programs that provide consistent results will increase the utilization of estrous synchronization and artificial insemination in the beef industry.
    4. The modified 7 d CIDR & TAI program through continued NC-1038 research, and the Select Synch + CIDR & TAI program resulted in greater AI pregnancy rates in beef heifers than the 7 d Select Synch + CIDR & TAI program.
    5. Delivering PGF2± at CIDR insertion and thereby reducing the circulating concentration of progesterone during the development of the follicle wave resulted in numerically greater growth of the dominant follicle. NC-1038 scientists continue to work on research focusing on estradiol prior to ovulation and to oocyte viability is not yet known.
    6. Understanding the basis for poor fertility in heifers and lactating dairy cows will increase farm income by increasing milk production through reduced days open and genetic improvement (widespread use of artificial insemination). The increase in milk production is conservatively valued at $100/cow.
    7. Increasing the proportion of recipient cows becoming pregnant after embryo transfer by 10% reduces significantly the cost of an embryo transfer business because the greatest fixed cost of the business is associated with procurement and upkeep of recipients (Looney et al., 2006). Therefore, for 100 recipients receiving an embryo, anywhere from 8 to 10 more recipients will conceive when treated with hCG at transfer.
    Last Modified: 21-Sep-2009

    Date of Annual Report: 09/15/2009

    Report Information:
  • Annual Meeting Dates: 09/04/08 to 09/05/08
  • Period the Report Covers: 10/2007 to 09/2008

    • Participants:
    Brief Summary of Minutes of Annual Meeting:
    Thursday, September 4:

    The meeting was called to order by Chairman William Silvia at 8:00 am.

    Thursday, Sept. 4

    8:00 - 8:30: Introductions and Registration

    Station reports:

    Vonnahme (NDSU collaborating with PF at UW):

    Linseed (flax) ND 95% rich in omega 3.

    Flax improves conception rate in several studies.

    Ambrose JDS 89:36

    Oil extracted flax to women increased length of luteal phase but not menstrual cycle length.

    Cost a limiting factor.

    Fatty acid composition of milk altered (post-rumenal).

    No improvement in reproductive traits.

    PF: Titer? Possible collaborative effort.

    LA: Source?

    KV: Different mills.

    GAP: No farm effect would resolve milling/source issue.

    CL: Analyzed? Percentage within pen?

    PF: Yes, pen experimental unit.

    JW: How widespread is sales for a collaborative efforts?

    PF: Price and availability issues.

    RK: Mechanism? Embryo?

    PW: Fed cows, superovulated and transferred. No effect.

    CL: Studies that show negative effect?

    PF: Unknown.

    JS: Variability of product.

    PW: Monthly bunk samples and milk samples. No fluctuation.

    KV: Nutritionists recalculated for fluctuations.

    RK: Pure form of oil for cell culture?

    KV: Can do omega-3.

    Fricke (UW):

    Double OvSynch.

    Key getting follicle to ovulate to GnRH.

    PF: P4 influence on response to GnRH?

    JS: Chenault no differences.

    PW: Re-synch trial. Natural collaboration type of trial. Students thesis.

    Break

    Silvia (UK):

    Baseline and magnitude of pulses of LH decreases from 0 to 1 to 2 CIDRs.

    LH response to GnRH suppressed in cows with 1 or 2 CIDRs.

    Ovulatory response unknown.

    JS: Need a CL group.

    GAP: Dose effect of P4 on LH release.

    Stevenson (K-State):

    PF: Pfizer wants to go forward with this positive data.

    JS: Too many injections. Need to increase CR 10-15%. Not economical! OvSynch of value. Additions just a cost increase.

    PF: Interventions diminishing returns.

    JS: Cherry picking needs to be taken advantage of.

    PF: Detection of estrus still an issue.

    Weber (UMaine):

    Serum thyroid hormone levels in early lactation related to risk of culling.

    JS: Days relative to calving?

    JW: Normalized to calving by 7-day periods.

    LA: Calcitonin levels/Parathyroid?

    JW: Have not looked at it.

    DH: Thyroid Hormone approved to treat?

    JW: Dont know. Iodine supplementation. Synthroid. Milk sales issues.

    Lunch

    Comments from Administrative Advisor, Bill Ravlin, CREES Representative, Deb Hamernik.

    Hamernik:

    Discuss changes under new Farm Bill. AFRI FY2009 RFAs released later in the year. AFRI Research RFA released by end of November 2008. No submission deadlines before Feb 1, 2009. AFRI Integrated RFA released after January 1, 2009. Two panels, research and integrated.

    Ravlin:

    Bill Koshar will submit report into system. Impact statements. Leverage collaborative efforts to compete for grant dollars.

    DH: Questions on integrated program RFA under new system.

    BR: Opportunitities.

    BS: has group ever submitted a grant as group.

    No.

    Paul: Report industry funding for NDSU/UW collaboration.

    BR: Summarize these in a table.

    Station Reports:

    Ottobre (The Ohio State):

    Boer have lower libido than Mubende.

    KV: Male oriented?

    JO: Unknown.

    Anderson (ISU):

    New University Dairy Farm may allow collaborations on the multistate project.

    Krisher (University of Illinois):

    Families of genes that are different between gilts (poor oocytes competence) and sows. Metabolism genes. Genes involved in oxidative stress. Tools for in vivo studies.

    Some families of genes in common between pig and mouse.

    Kesler (University of Illinois):

    Co-Synch plus CIDR with removal of calf for 60 h increased pregnancy rates.

    JS: What do you feed the calves?

    CL/AB: Creep feed or high quality forage.

    JS: Geary: calf removal data influenced by parity.

    DK: Did look at parity. Not enough animals to break it out.

    CL: Does calf removal influence cycling and non-cycling animals differently.

    DK: Need to have the facilities for the calves.

    Bridges (Purdue):

    5 day CIDR. Issue: Need 2 shots of prostaglandin. Can use 5 day without CIDR? Would it work in anestrous cows?

    Mature cows: possibly no benefit of CIDR.

    Too much progesterone: Mid-luteal, possible accessory CL, and CIDR.

    CL: Give prostaglandin at CIDR insertion.

    CL/JS: GnRH and prostaglandin at same time. Partial luteolysis but delayed structural luteolysis. Result: Short cycle.

    AB: Anyway that you can decrease P4 and increase LH increase pregnancy.

    RK: Actually increasing LH?

    AB: Hypothesis

    DK: 5 day CO-Synch without CIDR has a lot of potential impact.

    GAP/CL: Consistency, costs, and better protocol for heifers.

    CL: 5 day gives options in the case of a storm or something unplanned 5, 6, 7 day CIDR removal.

    Perry (SDSU collaboration with RAC at USMARC):

    LH but no ovulation. Why?

    JS: Anybody tried monoclonal LH antibodies for any species.

    JW: Has worked with a company.

    JS: Is a prepubertal heifer anestrous.

    GAP: Define pre versus peri?

    JS: Anestrous not acceptable if I was a reviewer.

    DH: More mucous associated with drop in pH.

    GAP: Not determined. Those that dont show estrus, very little mucous. 5 minutes per cow to pH on average.

    6:30: Dinner

    Friday, Sept. 5

    8:00 - 8:30: Business Meeting: Election of Secretary and selection of meeting time/place for 2009

    2009 Meeting:

    Omaha, Aug 20, 21

    Chair: Cushman

    Secretary: Vonnahme

    Member at Large: Bridges

    Funston (UNL):

    Okay with dates and location for 2009.

    Fetal programming: Late gestation nutrition. Supplementing not beneficial. Carcass weight and quality in supplemented steers. Feed efficiency of heifers from non-supplemented cows more efficient, maybe due to lower perceived nutrition in utero. DDG: Significant increase in AI conception rate for heifers developed on DDG. DDG on first calf heifers fewer cycling but no difference in conception.

    KV: Supplement arginine and increase blood flow to uterus. Arginine content of DDG?

    BS: Is there a large beef collaborative project?

    CL: Discussion potential

    Stevenson (K-State):

    RK: Progesterone positive effects

    JS: Possible, Inskeeps data suggests a threshold. Systemic circulation not reflective of the uterus.

    GB: Cost of shot of hCG

    JS: 10,000 unit ~$24.00. Chorulon on back order. InterVet still extracting from placentas instead of cell line.

    GB: How do I recommend non-approved methods to producers?

    PF: OvSynch not FDA approved.

    JW: Vet extra-label use.

    CL: From extension stand-point stick with reproduction task force recommendations.

    GAP: Can talk about it.

    DK: Avoid the word recommend

    PF: Show data do not say This is what I would do

    CL/GAP: Recommend? Stay with reproduction task force.

    JW: Immune response to hCG

    CL: A few years ago 3 or 4 time.

    JW: Within 1 season. Next year refractory.

    CL: GnRH not effective on smaller follicles.

    PF: Wiltbank hCG in dairy cattle that supports JS data.

    JS: Not published. Ray Nebel has it too.

    JS: Larger response in second service cows. 80% of dairy cows.

    PF: Day 28 vs. Day 33 Ultrasounds

    JS: When did Santos do it?

    PF: 28. Very meticulous.

    RAC: Believe that loss between 28 and 33 is what we are seeing.

    KV: Important window

    JS: d6-7, recognition of preg d 15, day 28 to 33

    KV: Blood flow spike day 25 to 30 as well as recognition of pregnancy?

    AB: ISG15 second spike?

    Lamb (University of Florida):

    Feed Efficiency Facility available for collaborations. 440 head Grow Safe. 1/3 of pens individual water intake.

    PF: Sexed semen in IVF and could not improve fertility. Sperm damaged.

    GAP: Need to reduce bull power with AI.

    Cushman (USMARC in collaboration with GAP at SDSU):

    12:30 Adjourn

    Accomplishments:
    Objective 1.

    To develop breeding programs to maximize pregnancy rates.

    Accomplishments/Outputs:

    Illinois

    Removal of calves at the onset of estrus synchronization results in a 10% increase in pregnancy rates to timed artificial insemination in beef cows.

    Indiana (Purdue)

    The 5 d CO-Synch program without the inclusion of a CIDR is an effective timed-AI protocol in mature lactating beef cows.

    Both the CIDR Select and the 5 d Hybrid CO-Synch + CIDR estrous synchronization programs are effective protocols to facilitate AI in beef heifers.

    Kansas Cows failing to be detected in estrus during 12 d after presynchronization of estrus, but treated with a progesterone insert had increased timed AI conception rates compared with controls (38 vs. 24%), but did not differ from cows inseminated after detected estrus (38%). This study demonstrates that fertility can be improved in a reduced population of cows not yet observed in estrus by applying a progesterone insert in conjunction with a timed AI protocol. Injection of beef cattle with 1,000 IU of hCG on d 7 post-TAI increased the proportion of pregnancies per AI as detected on d 34 and increased the incidence of multiple ovulations in pregnant beef cows. Injection of beef cow recipients with 1,000 IU of hCG on d 7 post-estrus (at the time of embryo transfer) increased the incidence of multiple ovulation in pregnant recipient beef cows. Insufficient replication of treatments precluded interpretation of the effects of hCG on pregnancy rates. Injection of beef cattle with 1,000 IU of hCG on d 26 post-AI had no negative effect on pregnancy rates of previously inseminated suckled beef cows diagnosed pregnant on d 33 after TAI. Although pregnancy losses between d 33 and 68 in beef cattle receiving TAI averaged 5.6% (n =837), injection of GnRH or hCG on d 26 post-AI had no effect on pregnancy losses (second month of pregnancy). Minnesota/Florida Estrus synchronization and fixed-time artificial insemination may or may not have a positive economic impact on subsequent weaned calves. However, the likelihood of increased economic gain appears to be dependent on the environment to ensure that calves sired by AI sires have the necessary nutrients to realize their genetic growth potential.

    Treatment of hCG prior to estrous synchronization with the CO-Synch + CIDR protocol may enhance fertility, but not if hCG replaces GnRH at TAI.

    We determined that presynchronization with hCG appeared to influence the percentage of cows with a corpus luteum on d -7 but failed to enhance fertility. In addition, replacing GnRH with hCG at TAI appeared to suppress pregnancy rates.

    Insemination of superstimulated donor cows with sexed semen resulted in lower transferable embryos and an increase in unfertilized ova than those cows inseminated with conventionally frozen semen Nebraska Low input heifer development systems result in acceptable AI and final pregnancy rates. Strategic supplementation of nutrients around the time of natural service or AI breeding may increase pregnancy rates in beef heifers.

    Late gestation supplementation of cows grazing winter range or corn residue impact subsequent steer and heifer progeny performance.

    South Dakota

    There was no effect (P = 0.2) of cycling status on induction of ovulation by a combination of GnRH and CIDR (7 or 9 days) (29/41 and 42/72 for cycling and peripubertal heifers respectively).

    Ovulation was induced in more heifers when GnRH and CIDR treatments were initiated synchronously (26/38; P < 0.05) or when GnRH was given 6 h before the CIDR (28/37) than when GnRH was administered 48 h after CIDR (17/38).

    There was no influence (P = 0.19) of treatment on concentrations of LH during the GnRH-induced LH surge.

    There was a negative effect (P < 0.01) of systemic progesterone on the concentrations of LH during the GnRH-induced LH surge.

    There was no difference (P = 0.11) in the magnitude of the LH surge between heifers that did and did not ovulate.

    USDA-MARC

    Observation of estrus, as determined by a rubbed Estrotect patch, between Lutalyse and artificial insemination increased conception rates.

    Wisconsin

    Pretreatment with PGF2± 12 d before initiation of Resynch increased fertility 66 d after TAI for cows with serum P4 concentration > 1.0 ng/mL at the first GnRH injection of Resynch and decreased pregnancy loss from 31 to 66 d after TAI.

    Double Ovsynch improved fertility to first postpartum TAI compared with Presynch/Ovsynch (primiparous cows), and may improve fertility to second and greater postpartum TAI compared to a 32-d Resynch strategy.

    Initiation of Resynch 25 d vs. 32 d after TAI did not affect fertility to TAI in lactating Holstein cows. In addition, earlier detection of non-pregnant cows using the PAG ELISA in conjunction with a TAI resynchronization program did improve the 21-d pregnancy risk compared with TU.

    Although treatment of anovular cows with GnRH 4 d after TAI failed to improve fertility, variation among cows in serum P4 at the PGF2± injection of Ovsynch dramatically affected fertility of anovular dairy cows.

    Use of exogenous P4 during TAI protocols improved fertility of lactating dairy cows not previously observed in estrus.

    Objective 2. To characterize physiological mechanisms that regulate ovarian and uterine functions.

    Illinois

    In vitro oocyte maturation, fertilization, and embryo culture to the blastocyst stage is possible in springbok, under semi-defined conditions.

    A high fat/high fructose diet affects progesterone production, triglyceride and cholesterol levels, glucose tolerance, ovary size and oocyte quality in Ossabaw pigs.

    Using ala-gln instead of gln was beneficial to oocyte IVM and increased oocyte maturation percentage. Including ala-gln instead of gln may result in increased developmental competence after fertilization by reducing ammonium buildup during the maturation period.

    Gene expression in porcine oocytes is significantly affected by maternal age as puberty approaches, as well as follicle size, and may be the basis for differences observed in developmental competence.

    Porcine oocytes can be successfully matured in defined maturation media without gonadotropins, when the media contains fetuin, recombumin and EGF.

    There are deleterious effects of ammonium on both nuclear and cytoplasmic maturation in vitro.

    Gene expression is altered in oocytes matured in vitro compared to those in vivo.

    Iowa

    There are subsets of the chicken somatotrope population in the anterior pituitary gland that differ in their ability to respond to various secretagogues.

    Mild fatty liver is detrimental to health and reproduction of dairy cows and exogenous glucagon decreases some of these detrimental effects.

    There is regional specificity of cellular transformation or interconversion within the anterior pituitary gland to facilitate GH and PRL secretion as the need for endocrine regulation during the rapid growth period in the young pig.

    Genistein may not affect the acute production of estradiol by bovine follicles, but may alter the long-term response to gonadotropin-stimulated estradiol production.

    Kentucky Two CIDRs implanted in lactating dairy cows produce approximately 2 ng progesterone/ml in the systemic circulation.

    2 ng progesterone/ml is not enough to significantly reduce LH pulsatility and thereby avoid the problem of persistent follicles.

    A single CIDR strongly suppresses the responsiveness of the pituitary gland to GnRH.

    Maine

    In dairy cows, T4 and T3 concentrations decreased from the euthyroid to the hypothyroid range from Day -45 until just after freshening.

    T3 concentrations subsequently increased into the euthyroid range by Day 20 postpartum.

    T4 concentrations had not reached euthyroid levels by the end of the sampling period.

    T3 concentrations on days -25 t0 +25 postpartum were significantly (P <0.01) and inversely related to positive died/cull outcomes.

    T4 concentrations below 3.2 mg/ dL (lowest 40% of all samples) from 0 to 25 days postpartum were associated with a significantly higher death/cull rate during the same lactation than samples with T4 concentrations greater than 3.2 mg/ dL (P =0.003).

    North Dakota

    Feeding linseed meal enhanced uptake of progesterone from CIDRs and clearance of progesterone after CIDR removal when fed to ewes. Feeding flax increased the concentration of omega-3 fatty acids in plasma. Reports of increased pregnancy rates in dairy cows fed flax may relate to P4 metabolism.

    Feeding oilseeds to beef during the time of estrus synchronization will not only increase the energy density of the diet but will provide key fatty acids that may enhance the recognition of pregnancy by the dam.

    South Dakota

    At time of AI, cows that had initiated estrus had decreased (P = 0.01) uterine pH compared to cows not in estrus (6.78 ± 0.03 and 6.89 ± 0.03, respectively).

    Cows that had initiated estrus by 18 h after AI had decreased (P < 0.01) uterine pH at time of AI compared to cows that did not initiate estrus (6.78 ± 0.02 and 6.96 ± 0.04, respectively).

    Cows that initiated estrus prior to AI had increased (P = 0.05) pregnancy success (52% vs. 38%) compared to cows that had not initiated estrus by AI.

    Cows that initiated estrus by 18 h after AI tended to have increased (P = 0.078) pregnancy success (43% vs. 32%) compared to cows that did not initiate estrus.

    Uterine pH at AI had an approximately linear effect on pregnancy success within the observed pH range. As uterine pH increased pregnancy success decreased (P = 0.076, logistics regression).

    Cows with high endogenous E2 had larger follicles (P = 0.02) on day 0 of the experiment than cows with low estradiol (15.0 ± 0.67 vs 12.3 ± 0.73 mm, respectively).

    Circulating concentrations of progesterone were similar (P = 0.95) between highE2 and lowE2 cows on day 0 (0.43 ± 0.05 and 0.43 ± 0.06 ng/mL, respectively), but were different (P = 0.02) on day 16 (3.52± 0.56 and 1.44 ± 0.62 ng/mL, respectively). Concentrations of progesterone increased (P < 0.0001) from day 0 to day 16 in highE2 cows, but only tended (P = 0.12) to increase in lowE2 cows.

    Relative expression of uterine milk protein precursor was greater (P = 0.04) in highE2 cows compared to lowE2 cows on day 0 (12.51 ± 3.07 vs. 2.10 ± 3.37, respectively). However, expression decreased (P = 0.002) from day 0 to day 16 in highE2 cows, and there was no difference (P = 0.95) in uterine milk protein precursor expression between highE2 and lowE2 cows on day 16 (1.11 ± 0.21 vs. 1.13 ± 0.34, respectively.

    Relative expression of inhibin beta A was greater (P = 0.03) in highE2 cows compared to lowE2 cows on day 0 (8.81 ± 1.64 vs. 2.82 ± 1.80, respectively), and expression decreased (P = 0.002) in highE2 cows from day 0 to 16. On day 16, there was no difference (P = 0.74) in inhibin beta A expression between highE2 and lowE2 cows (0.28 ± 0.03 vs. 0.29 ± 0.05, respectively).

    Expression of proenkephalin was not detectable in either highE2 or lowE2 cows on day 0. However, relative expression of proenkephalin on day 16 was greater (P = 0.02) in highE2 cows (10.40 ± 1.95) compared to lowE2 cows (2.70 ± 2.49).

    Relative expression of oxytocin receptor decreased (P < 0.001) from day 0 to 16 in both highE2 (10.24 ± 1.43 and 1.31 ± 0.49, respectively) and lowE2 cows (9.77 ± 1.10 and 1.03 ± 0.48, respectively), but there was no difference between highE2 and lowE2 cows (P = 0.66 and P = 0.51) on day 0 or 16, respectively.

    Relative expression of estradiol receptor alpha decreased (P < 0.01) from day 0 to 16 in both highE2 (10.14 ± 1.52 and 4.57 ± 0.50, respectively) and lowE2 cows (13.45 ± 1.73 and 5.35 ± 0.76, respectively). However, there was no difference between highE2 and lowE2 cows (P = 0.16 and P = 0.37) on day 0 or 16, respectively.

    Relative expression of nuclear progesterone receptor decreased (P < 0.0001) from day 0 to 16 in both highE2 (13.28 ± 0.95 and 2.43 ± 0.34, respectively) and lowE2 cows (13.21 ± 1.09 and 2.66 ± 0.52, respectively); however, there was no difference between highE2 and lowE2 cows (P = 0.96 and P = 0.69) at either time point.

    USDA-MARC

    A decreased antral follicle number was associated with decreased conception rates to artificial insemination in 7- but not 8-year-old cows.

    Cows that were open in two consecutive years had fewer antral follicles than cows that were open one year and conceived in the next year.

    Preliminary analysis of SNP Chip data using PLINK has identified a candidate region flanking anti-Mullerian Hormone (AMH) on bovine chromosome 7 that associates with antral follicle counts in heifers.

    Evidence from both the ultrasonography and the ovaries collected at necropsy suggests that antral follicle counts begin to decline earlier than described in previous reports (Erickson, 1966).

    Period 1 mRNA levels were elevated in the ovarian cortex of cows that did not demonstrate estrus during the synchronization procedure, but not in adipose.

    MicroRNAs are expressed in bovine oocytes and may play a role in coordinating mRNA stability and translation during oogenesis.

    Wisconsin

    Feeding 0.85 kg flaxseed/cow/d (DM basis) can alter the fatty acid profile of milk while maintaining milk yield and composition in on-farm dairy applications, however, reproductive performance of dairy cows was not affected.

    Supplementing organic trace minerals had no effect on DMI or health events and only affected milk production later in lactation, BW at 1 month post calving, and BW change f

    Impact Statements:
    1. Results from current and ongoing research at cooperating stations have been used to make recommendations to stakeholders and their consultants regarding implementation of systematic synchronization and resynchronization systems for both dairy and beef cows. Fundamental research on the all aspects of reproduction in cattle will lead to improved fertility. Research conducted in other species has application to improvement of fertility in cattle as well. Data generated in these projects have been published in scientific journals and included in numerous extension proceedings. Specific impacts are listed below.
    2. Reproductive inefficiency is one of the most costly and production-limiting problems facing both the dairy and cow-calf industries. For example, in six Midwestern states that comprise the Heart of America Dairy Herd Improvement Association, 17.4 % of the dairy cows were culled because of reproductive failure. It was only exceeded by death (18.2 %) as the leading cause of culling (Heart of America Annual DHIA Summary). Similar statistics are reported by other DHIA organizations in the U.S.
    3. A comparative analysis of gene expression in oocytes of differing qualities will establish which genes might be targets for manipulation to improve developmental competence. This information will allow us to develop strategies to enhance oocyte maturation, assays to test for oocyte quality and improved media formulations for in vitro oocyte maturation. The production of competent oocytes will positively impact the application of nuclear transfer and transgenic technologies to animals for agricultural and biomedical purposes.
    4. Injecting previously inseminated beef cattle with hCG 7 d after AI improved pregnancy rates by 10.1 percentage points, translating into 10 more AI calves per 100-cow herd. Applying progesterone insert to dairy cows not previously detected in estrus increased pregnancy rates by 12.6 percentage points, translating into nearly 13 more calves, shorter calving intervals, and reduced risk for culling. If 30% of cows are inseminated based on detected estrus and 75 cows per 100 are treated with a progesterone insert as part of a timed artificial insemination (Ovsynch) protocol and pregnancy rates are increased by 12.6 percentage points, the cost per 100 cows inseminated would be $59.52 per pregnancy (75 ´ $10 per progesterone insert ¸ 12.6). When pregnancies are valued at $50 to $150, depending when they are initiated after calving, payback on investment for use of the progesterone insert is very likely.
    5. Improved procedures for estrous synchronization in heifers and lactating dairy cows will increase farm income by increasing milk production, through reduced days open and genetic improvement (widespread use of artificial insemination). The increase in milk production is conservatively valued at $100/cow.
    6. Developing methods to enhance response of follicles to fixed-time AI protocols is critical to enhancing overall pregnancy rates to those protocols. Therefore, the potential for the use of hCG in estrus synchronization protocols could enhance fertility to females exposed to fixed-time AI and result in a greater proportion of AI sired calves. In addition, improvement in fertility will generate more interest by beef producers to utilize fixed-time AI estrus synchronization systems, thus enhancing the overall use of AI. Understanding factors that enhance profitability after the use of estrus synchronization and AI will allow producers to potential alter losses exceeding $16 per synchronized cow to yielding profits exceeding $13 per synchronized cow.
    7. Low input heifer development systems have resulted in a $70/head savings per pregnant heifer over conventional heifer development systems.
    8. Supplementation of pregnant cows grazing winter range or crop residue results in a $75 increase in net return of steers fed to harvest.
    9. Supplementation of different feedstuffs may enhance pregnancy rates in cattle. Not only can fat supplementation influence pregnancy rates, but phytochemicals, particularly those found in flax, are showing potential to impact reproductive performance as well.
    10. Supplementing the diets of lactating dairy cows with flaxseed can alter milk composition, increasing its nutriceutical value and may also enhance reproductive performance.
    Last Modified: 12-Jan-2009

    Date of Annual Report: 09/28/2010

    Report Information:
  • Annual Meeting Dates: 09/02/10 to 09/03/10
  • Period the Report Covers: 10/2009 to 09/2010

    • Participants:
    Brief Summary of Minutes of Annual Meeting:
    Thursday, Sept. 2

    8:00  8:30: Introduction and Registration. Room was $390. Registration was $30 per person

    Several positions are open and/or have been recently been filled at the participating universities.

    2010 is Kimberly Vonnahmes last year as a member of NC-1038. Carl Dahlen will replace her as NDSU representative.

    2010 is Allen Bridges last year representing Purdue University. Allen will represent the University of Minnesota in future years.

    Station Reports:

    Kimberly Vonnahme (NDSU): Endocrine profiles change when nutrition is altered. Exp with pigs, exercised pigs for 3x week during gestation and measured umbilical blood flow. Exercise at 65 d increased umbilical blood flow (litter size did not differ). Exercise increased ovary and uterine size.

    Impacts of maternal nutrition on uterine blood flow in beef cows throughout gestation USDA funded project: hypo: when to intervene in low nutrition in during gestation. Does placenta has ability to respond during late gestation. No restriction, short-term restriction, long term restriction. Spectral analysis to measure flow. Measure flow volume, 3 times in triplicate. And resistance index to measure vasoconstriction. Nutrition has altered blood flow during gestation. 60% restriction is both energy and protein. Going to work with Funston on protein model. GP?: Statistical analysis of individual fed cows on intake with more than 1 in pen. If suppose to eat 60% and 1 cow is 55% and one at 65%. When to numbers out-weigh individual measurements? When do you have enough animals to account for variation? Discussed in depth. No clear answer. Many manuscripts wont be accepted.

    KV: High selenium during gestation increased milk production potentially due to increased mammary vascularity.

    G. Cliff Lamb (University of Florida): Grow-Safe (GS) system is very accurate (~98.5%) at estimating feed intake. However, the Nelson water systems are not reliable. When determining residual feed intake (RFI) using GS, use a 21 d adaptation period and 70 d test. Obtaining accurate weights on cattle is more challenging than obtaining feed intake. Determining the relationship between feed efficiency (FE) in growing and mature females. Do females maintain similar FE as weaned heifers and following calving of 2nd calf; does an efficient growing female = and efficient mature female? Growing FE does not accurately predict mature FE when milk production was not included into the statistical model. Question by BC: Even with a poor correlation between growing and mature females, can you identify genetic markers that can account for both periods? CL: Good question; how much is FE associated with genetics, biology, and environment and can it be selected for? Inefficient heifer consumed ~1,000 more lb of feed during the 70 d test than the efficient heifer, with a similar relationship seen in cows. Question by KV: How do you know a specific cows 100% feed intake, all animals will differ? When heifers and cows were ranked as good, medium, or bad in terms of FE, the group relationship was still evident as mature females. Statement by GP & CL: Should evaluate both wt change and % wt change as data can differ.

    Determination of the appropriate delivery of PGF in the 5 d CO-Synch + CIDR protocol in lactating beef cows. Treatment: a) Single 25 mg of PGF at CIDR removal, b) two concurrent 25 mg doses of PGF (Co-PGF) at CIDR removal, c) two, 25 mg doses of PGF given 8 h apart. TAI pregnancy rates similar to lactating dairy cows, very poor even though DPP and BCS was greater than in previous years. TAI pregnancy rates were greater in the 8 h-PGF treatment (46.9%; n = 64) than the 1x-PGF (26.6%; n = 64) and Co-PGF (21.0%; n = 62) treatments. Breeding season pregnancy rates did not differ between treatments.

    Effects of 72 h temporary calf removal prior to fixed-time AI on pregnancy rates and subsequent calf performance in suckled beef cows. Calf removal for 72 h tended to increase pregnancy rates, while having negative impacts on subsequent calf performance. TW calves were 16 kg smaller at weaning than controls At the time of temporary weaning (TW), the youngest calves lost the most weight during the weaning period.

    Discussion: Question: Is the loss in calf performance due to direct effects on the calf (immunity and feed intake) or cow milk production? JS: Suggested to keep calves close so that they dont lose bonding with mothers KV: Skip Barols data: lactotrine (sp?) in milk may be as important as colostrum in swine and hence the reason for decreased performance to TW. CL: Young calves lost more wt during TW but older calves had decreased WW. JS: After TW, different milk components take different intervals to come back. GP: Can/should you measure calf milk intake? IS there a change in gut function due to lack of feed? CL: Intensive measurements are planned using the GS system.

    Improving growth development and attainment of puberty of replacement beef cattle heifers with perennial peanut forage Objective was to determine if supplementing perennial peanut forage was a viable alternative to supplementing cereal grains to developing crossbred beef heifers. Treatments: Control: ad lib bermudagrass hay, Peanut: ad lib hay + 3/week supplement with perennial peanut forage, Grain: ad lib hay + 3/wk grain supplementation. Peanut and grain diets were isocaloric and isonitrogenous ADG was greater in the peanut and grain treatment than the control treatment. Age at puberty did not differ between treatments but weight at puberty was greater in the grain and peanut treatment than the control.

    Bob Cushman: Reproductive tract measurements and granulose cell gene expression in repeat-breeder cows Repeat breeder cows were those that failed to conceive in 2 consecutive breeding seasons. It was hypothesized that repeat breeder cows would have smaller reproductive tracts and fewer antral follicles than fertile females. Repeat breeders had smaller ovaries and fewer follicles than fertile cows which may contribute to their reduced fertility. Repeat breeders also had decreased mRNA for anti-mullerian hormone.

    Discussion: Antral follicle counts dont explain everything as only 10% pregnancy rate difference between high and low females. AT: any dud ovaries in repeat breeders? BC = no RK and BS pointed out that repeat breeder beef cows and repeat breeder dairy cows differ as you dont know how many times the repeat beef cow was actually bred. BC: Antral follicle count is affected by day of the estrous cycle but ovarian size and uterine endometrium area is not and thus may be useful to include in a reproductive tract score and for heifer selection. Question from group: is fertility related to large reproductive tract and ovary? BC is getting phenotypes for continued studies in antral follicle count (AFC) and fertility SNIP study by BC: Titan gene spikes in cows with high AFC. Titan is a muscle associated gene that is expressed in the ovary. A SNIP study with cluster pathways identified several genes of interest close to Titan: growth hormone receptor, AMH, BMP receptors For the variables; age at puberty, antral follicle count, heifer pregnancy rate, and birth weight  15 SNIPS were significant for all. Future research by BC: estrous detection data on heifers for 15 years to look at gene clusters close to significant SNIPS

    Using growth traits and adipose function to identify indicators of heifer fertility Adipose tissue could be used as a biomarker of fertility and be linked to growth traits and feed efficiency in heifers Beef heifers were observed for estrus beginning at 6 months of age. A adipose tissue biopsy was taken at approximately 1 year of age, and heifers entered the breeding season at ~416 days of age. Heifers that were prepubertal at biopsy were younger and lighter at weaning than pubertal heifers but pregnancy rate did not differ nor did weight at breeding. Age at puberty did not impact pregnancy rate. mRNA for peroxisome proliferator-activated receptor-g in adipose tissue did not predict fertility. BC future research: continue collecting data on heifer ovary size, endometrial weight, and carcass composition to relate to fertility Question by AT: is there a national or international effort to bring all SNIP data together? Issue-phenotype variations Full access to several other SNIP data sets are available.

    Paul Fricke: To resynch or not to resynch - that is the question As the number of AI attempts increases the conception rate to AI decreases, therefore resynch AI conception rate is reduced. General research question: Can resynch AI pregnancy rates be increased? If so, reproductive performance of dairy herds can be dramatically improved. Most producers will incorporate estrous detection with resynch-TAI approaches.

    Effect of presynchronization with GnRH or hCG 7 d before resynchronization of ovulation initiated 25 d after a previous timed AI on fertility of lactating dairy cows. Comparing the efficacy of administering either GnRH or hCG 7 days before the initiation of a common resynchronization protocol in lactating dairy cows. Failure of cows having a CL at initiation of resynch results in low progesterone concentrations and reduced fertility. 15 to 20% of cows fail to have a CL at start of resynch. Question by AB: is it a direct effect of progesterone or more related to stage of the estrous cycle? PF: most data suggest in is a direct effect of progesterone. Administering GnRH or hCG 7 d prior to start of a resynch protocol did not improve synchronization rate. hCG improved fertility compared to GnRH, but GnRH was better than control.

    Discussion: Why do some many cows not have a functional CL at start of resynch? Answer not clear.

    Presynchronization with hCG 7 d before initiation of Resynch improves fertility similar to a Double-Ovsynch Resynch protocol in lactating dairy cows. Using a double ovsynch as resynch extends the interval to AI by 7 days but has been shown to increase AI conception rate by 8%. What is value of increased conception rate versus increased time to AI? Objective of hCG is to increase progesterone at start of resynch program to enhance fertility. Administering hCG 7 d prior to start of resynch program resulted in similar fertility at using double ovsynch and reduced the interbreeding interval by 14 d.

    General Discussion: Concern expressed by group: Administering GnRH during periods of elevated progesterone results in reduced incidences of ovulation. Perhaps use hCG rather than GnRH? Question: appropriate dose of hCG: JS: Although PF used 2000 i.u., 1000 should be as effective and is the current recommendation. Concerns expressed by the group the hCG may be taken off the market. GP and AB: expressed that elevated progesterone may be a hindrance in beef cattle, specifically heifers. Question - Does hCG cause antibody development?  Yes, cows will develop antibodies against it.

    Serum pregnancy-associated glycoprotein (PAG) and progesterone concentrations after induction of pregnancy loss at Day 39 of gestation in lactating dairy cows Many different PAGs, expression pattern differs during gestation. Discussed various pregnancy diagnosis options using varius PAGs and interferon stimulated gene products. Question posed is how long do PAGs stick around once pregnancy is lost? Fetuses aborted on d 39 of pregnancy via PGF (slower death/faster expulsion) or saline infusion (immediate stop in heart beat/slower expulsion). Group discussed various ways to abort the fetus. Serum PAG decrease at a similar rate regardless of method to induce abortion. GP shared cut-off serum values for pregnant, non-pregnant, and not sure for BioPrYN test

    A Stochastic Evaluation of Reproductive Management Programs for Dairy Herds

    Economic modeling suggests that breeding costs are trivial compared to returns from getting cows pregnant at fewer days in milk.

    Reproductive efficiency is biggest driver of economic outcome in model

    Economic model available for producers on University of Wisconsins website

    Washington Update provided by AT:

    NIFA is being reorganized in to 5 institutes: 1) Animal programs in food production and sustainability, 2) Bioenergy, 3) climate, and environment, 4) Food safety and nutrition, 5) Youth and communities

    Also the Center for International Programs

    Congress has to approve changes

    Current plan: implement changes after start of new fiscal year (Oct. 1)

    What it means for animal science: - Brings everyone together; competitive side aligns with non-competitive program

    RFAs for next year are underway: goal to have out in November or December -Some people addressed concerns with current grant programs

    Foundation grants wont rotate between research areas

    Integration and collaborations is critical: multi-discipline/institution Positive note: AFRI fellowship program: $130,000 limit-Deadline is Oct 5th. Hot off press: New grant opportunity: NIH-NIFA; Administered thru NIH. Joint FOA for dual use of domestic animals and biomedical research. To address issue with large animals that we can use models for human disease. Dual use is key. Human health and biology of ag species. 4 main topic areas: assisted repro technology and stem cell biology, metabolism, developmental origins of adult disease, zoonotic diseases Mark Mirando worked hard to get in place, if questions call Mark. Letters of intent are option, due Oct. 3rd, final due date is Nov 3rd. Grant workshops: Primarily toward new faculty: Arlington VA: Nov 30 and January 25th. (2 d workshops) Budget discussion: President to Senate to house then work out differences July: as of now thru senate. No new money. If increase, it is coming from somewhere

    AT went over budget details

    Discussed SARE proposals and process

    KV: What is the women and minorities in science, technology, engineering, and mathematics (STEM) fields: Answer: Dont know

    AT discussed new program leaders and recent personnel changes

    Lunch Break: 12:00 to 1:30 pm

    Station Reports Continued:

    Jeff Stevenson:

    Post-Embryo Transfer Stimulation of Luteal Function with Human Chorionic Gonadotropin

    Can embryo transfer (ET) pregnancy rates be improve with administration of hCG at the time of transfer?

    Embryos only transferred into cows with viable CL.

    Only 1 hCG treated cows with 3 CLs

    hCG increased the proportion of pregnant cows with multiple CLs and increased circulating progesterone concentrations

    Treatment, embryo type (fresh vs. frozen) and BCS affected ET pregnancy rates. hCG increased pregnancy rates.

    Little research on the impact of receipt BCS on pregnancy rate.

    At transfer CL scoring (1 vs 2) was done. Cows with a score of 1 had greater progesterone than those with a score of 2. Group discussed impact of BCS of donor, receipt, and effect of embryo development on pregnancy rates to ET.

    Use of Equine Chorionic Gonadotropin to Stimulate Pregnancy Outcomes in Suckled Beef Cattle

    Heat stress negatively impacted pregnancy success.

    Administering eCG at CIDR removal decreased pregnancy rate compared to controls, but extreme heat stress at one location may have impacted results.

    Enhanced Ovulation in Lactating Dairy Cattle before and after First Services

    PG-3-G-7-G versus Presynch+Ovsynch

    Does giving PGF followed by GnRH 3 d later, initiated 10 d prior to the start of Ovsynch increase synchronization rates and TAI pregnancy rates compared to a standard 2 doses of PGF given 14 d apart with the 2nd PGF given 10 d prior to Ovsynch. More cows in the PG-3-G treatment ovulated at start of Ovsynch

    Pregnancy rates were numerically greater in PG-3-G treatment (preliminary results)

    Second objective was to administer hCG on d 6 after TAI to induce an accessory CL and potential increase TAI pregnancy rates.

    A greater proportion of hCG treated cows had multiple CLs and pregnant cows that received hCG had greater progesterone concentrations after on d 21 and 28 than pregnant cows that did not receive hCG.

    hCG administration did not increase TAI pregnancy rate.

    Discussion:

    PF: have you broken out a parity effects? JS: No parity effect CIDR put in CIDR in vagina what CIDR sees does not reflect what is circulation Effect on hypothalamus: P4 above 1 ng/mL so probably not impacting LH release and no persistent follicles PF: population of cows without CI: original CL volume in hCG preg and salin preg: has CL increased volume by d 21 and 28 Interesting on d 14 hCG differs from Saline Discussed P4 effects on fertility in dairy versus beef during development on follicle wave.

    Bill Silvia:

    The temporal relationships between physiological, endocrine and behavioral parameters during the periestrual period in lactating dairy cows

    Past research: cystic ovaries in cattle associated with intermediate concentrations of p4. Level of p4 needed to inhibit an lh surge is extremely low (.4 ng/mL). Inhibiting pulse secretion has to be much higher to suppress LH pulse frequency (4.0 ng/ml). Why is this? Different centers of hypo respond different to p4 level, genomic vs non-genomic, receptor type??? JS: CIDR + CL- is direct action of p4 from CIDR on CL? CL has high p4 anyway. PF: if a cow hasnt seen p4 in a while liver not ready to metabolize. KV: diet can change P4 catabolism AT: OVX changes hypo-pituitary What happens to P4 immediately after CIDR in with CL already-no one knows JO: Couldnt it be that CIDR just impacting LH Current data: Holstein or Holstein x Jersey, any lactation, first breeding postpartum (60 to 100 d). Synched with G6G followed by Select Synch 3 d prior to PGF: smart bolus (temperature sensor, accelerometer) put in reticulum and vagina (attached to CIDR). Constant signal After PGF: check for estrus 2 h intervals until 3 consecutive checks without mounting Bleed 2 h interval for LH (until 24 h after onset of estrus or 120 h Rectal temp at 2 h intervals Ultrasound at 4 h interval o monitor follicle growth and ovulation Measured various intervals. Objective: identify interval with lowest deviation: best predictor of ovulation, know best time to AI. Accelerometer in reticulum: do see a spike at estrus (various transient) Body temp rise associated with estrus. Vaginal temp: goes up, less noise than reticulum Future research: both smartbolus (reticular and vaginal) and ice Tags (leg mounted accelerometer Identify motion signature for mounting events: 1) examine motion at maximum frequency, 2, examine motion in 3 dimensions, 3, mounting versus standing Can we see motions signature profiles between cows in heat and not, and relationship with cows in and not in estrus (interaction). LA: use video cameras on cows Use heat watch (GP) RK: how does sensor measure movement of cow versus tumbling in reticulum? BS: dont think can separate that out? RK, will that mask actual animal movement? BS: yes PF: So when you got a small difference in temp due to estrus, what happens during heat stress. BS: Dont have data evaluated yet, but may be impacted. None showed heat but some did ovulate. Very hot in august. BC: a potential use for temp in beef is to uses with bull to know day of conception CL: if acute changes could be predicted, great use in dairy if data returns fast enough JO: when I first went to OSU: Zartman temp. Joe has some papers published. Thought vagina temp had promise.

    George Perry: Influence of luteal regression prior to GnRH on LH pulse frequency and synchrony of follicular growth PGF-CIDR program: Tighter synchrony of follicle development better follicle control Tighter control of progesterone Hypothesis: does this impact LH pulse and follicle growth Treatments: PG-CIDR, PG-NoCIDR, 7d CIDR LH bleed 4 d after CIDR inserted PF: why 6 and not 5. GP: no need for 2 shots of PGF, also d 6 optimal follicle sizes from dissertation Less variability in p4 concentrations, follicular growth, and dominant follicle size at PGF in PG-CIDR LH pulse frequency tended to be greater in PG-CIDR and PG-NoCIDR than 7dCIDR treatment Influence of initiating luteal regression prior to treatment with GnRH on fixed time AI fertility in beef heifers. 5 d CO-Synch + CIDR vs PG-CIDR: 5 d = 42% (n = 265); PG-CIDR (64%, n = 252) Influence of initiating luteal regression prior to treatment with GnRH on ability to control follicular waves. Does inducing luteal regression improve response to GnRH-1: 5d vs PG-CIDR Yes: PG-CIDR (83%), 5d (64%)  all cows; same relationship when evaluated cows with follicles > 10 mm. PF: with pg-cidr, do you need a cidr? GP: only time looked at was in 5 heifers, argue yes to get consistent p4. PF: dont need GnRH at start of 5d CIDR in dairy heifers. CL: in beef heifers have to deal with prepubertal, cidr gets more cycling Objective 2: characterize physiological mechanisms Uterine expression of Na+/H+ antiporters 1, 2, and 4 in beef cows following CIDR removal.

    Na/H antiporters were not affected by estrous expression. Time affected antiporter 1 and 2 and there was an estrus by time interaction for antiporters 1, 2, and 4. AB: estradiol concentrations were high at PGF? GP: typical of our assay RK: are cows predestined not to show estrus/or have drop in uterine ph as antiporters were diff at start Effect of ovulatory follicle size on luteal weight and steriodogenic enzyme expression Cows that show estrus tended to have larger follicles but no difference in luteal wt Ovulatory follicle size tended to be positively correlated with luteal wt on d 10 When grouped, ovulatory follicle size impacted progesterone Estrous expression did not impact progesterone No difference in gene expression in CL from large and small follicles

    Jamie Larson:

    Modifying the Double-Ovsynch protocol to include human chorionic gonadotropin to synchronize estrus in dairy cows and heifers.

    Substitute 1st GnRH of double ov with hCG. Replacing GnRH with hCG did not increase pregnancy rates or ovulation rate but limited numbers. Repeating study in cows to increase numbers JL: Does doing heat detection following AI dirty up the data? PF: good question, can change dynamic of protocol. JL: after you AI all the first time, on return heat do you AI PF: good question: need to know information and heat expression between treatments. How do you know cow is heat? JS: are you testing a protocol or system. System yes, testing protocol = no. PF: swap GnRH with hCG at 2nd GnRH of double ovsynch (not first gnrh of breeding ovsynch). Why would swaping 1st assist fertility? GP: why hCG over GnRH PF: in resynch we wanted to ov follicle high p4, benefit to CL, hCG does better than GnRH. Werent convinced a single GnRH enough would ovulate?

    Effects of bull exposure on conception rates to artificial insemination in beef cattle Effect of bull exposure on conception rates to AI in beef cattle Control (no bull), side-winder bull, vasectomized bull JL: How to improve detection with bull chin markers?: had problems Could use detectors on cows, but dont know if cow or bull mounted. Other potential methods include vaginal swabs and video Conclusion of Station Reports on Day 1 (Sept 2) Business meeting: Rewrite due in 2011 2011 president is Allen Bridges 2011 secretary: Rick Funston 2011 member at large: Jamie Larson When and where 2011 meeting: Site: Fargo (11 votes) vs St. Louis (3 votes) Time: August 10, 11 2011 Direction of rewrite: 2011 station reports; 15-20 minutes: favorite project (not multiple) two full days: to focus on rewrite.

    ADJORN DAY 1 (5:00 pm)

    Day #2 (Sept 3, 2010) Station Reports Continued (8:10 am) Joe Otterbre Objectives: determine if exogenous PGF2± affects the concentrations of mRNA for sodium dependent Vitamin C transporters (SVCT) 1 & 2 in sheep corpora lutea, and to determine if the effect is dependent upon whether the corpus luteum has, or has not, acquired luteolytic capacity. Vitamin C (antioxidant): control free radical in CL Vit C decrease in CL after PGF: d 3 transient (down at 2 h post-PGF but back at 24 h post-PGF), d 10 stays suppressed Does SVCT1 and SVCT 2 mRNA change between d 3 and 10 SVCT1 mRNA was not able to be amplified SVCT2 mRNA was decreased after PGF administration during the mid-cycle but not during early cycle Discussion topics covered: Is it cause and effect? Can you inhibit SVCt 2? Does Vit C play a role in progesterone secretion? : Yes Does CL synthesize Vit C: NO How does Vit C get back out of cell? Leak after transporter destruction? Is SVCT in large or small luteal cells. Standard curve of real-time PCR of SVCT2

    Rebecca Krisher:

    GLUTAREDOXIN PATHWAY GENES ARE DIFFERENTIALLY EXPRESSED IN MATURE PORCINE OOCYTES WITH VARYING DEVELOPMENTAL POTENTIALS Gene expression in pig oocytes: Gilt (poor oocytes) vs sow (good oocytes) Several genes upregulated in poor oocytes 13 genes: redox, metabolism etc identified and examined in more detail. Glutaredoxin pathway activity may be different in gilts and sows, thus the potential difference in oocyte quality between them.

    EFFECT OF LEPTIN ON PORCINE NUCLEAR MATURATION UNDER CONDITIONS OF HYPERGLYCEMIA Leptin and glucose interact to regulate nuclear and cytoplasmic maturation of the oocyte.

    IDENTIFICATION OF DEVELOPMENTAL COMPETENCE RELATED GENES IN MATURE PORCINE OOCYTES

    The differential expression patterns of genes involved in cholesterol synthesis, fatty acid oxidation and glycolysis in good and poor quality porcine oocytes suggest that activities of these metabolic pathways may be important mechanisms involved in oocyte competence.

    BASELINE AND SUPEROVULATION HYPERANDROGENISM AND FOLLICULAR DYNAMICS IN THE OSSABAW PIG SUGGEST AN ANIMAL MODEL FOR POLYCYSTIC OVARIAN SYNDROME (PCOS) Effect of obesity on gene expression in oocytes MetS pigs had different amounts of androstenedione in serum and follicles as well as difference in progesterone. POS = more endometrial cancer, RK has uterine tissue

    EFFECT OF REACTIVE OXYGEN SPECIES DURING IN VITRO MATURATION ON PORCINE OOCYTE NUCLEAR MATURATION AND DEVELOPMENTAL COMPETENCE

    Functional work: Redox potential in oocyte quality: -to much cystiene is bad but in high redox, adding cystiene helps Important to keep Redox and oxidative agents in balance for proper oocyte development Question from group: does XOD1 or D10 run out because not replaced: probably THE EFFECT OF TNF- ‘ ON MEIOTIC MATURATION AND BLASTOCYST DEVELOPMENT. Blocking TNF-alpha reduced cleavage and blast % Question by AB:When trying to enhance oocyte quality are we directly impacting oocyte or just granulose cells. Discussion: Both

    Allen Bridges:

    Effect of PGF2± administration and CIDR insertion on timed-AI pregnancy rates in beef heifers.

    PGF at CIDR insertion did not increase TAI preg rates. Changing timing of TAI after CIDR removal in 5 d CIDR program did not increase TAI pregnancy rates.

    BCS important factor in results between locations

    Need to assess impact of puberty status on synchronization systems but difficult on cooperator ranches Group discussed role of progesterone between dairy and beef cows/heifers

    Circulating concentrations of progesterone in ovariectomized beef heifers when treated for 5 days with either a new, 5 day-used, or 10 day-used CIDR.

    Even after two uses, CIDR maintained progesterone above 1 ng/mL

    GP: Lower p4 could change LH pulses and impact timing of estrous and ovulation. Hence may alter TAI pregnancy rates. AB: True, must evaluate before making a recommendation towards using used CIDRs in 5 d program Group discussed progesterone concentrations reported.

    Determining the impact of feeding DDGS to gestating heifers on their reproductive performance and subsequent performance of their offspring

    Excessive protein did not impact AI pregnancy rates but did increase calf birth weight.

    GP: protein may not be high enough to cause detrimental effects

    KV: should use term developmental programming rather than fetal programming: more descriptive of what may be occurring

    Lloyd Anderson: Nanobiology of neuroendocrine secretion Mechanism of GH secretion using pigs as a model Secretagogue: induces GH secretion from hypo-pituitary homogenous mix within 90 seconds Total population of vesicles remains the same after secretion. Means the vesicle makes a transient membrane to fuse and release product Rapid and regulated process. Aquaporin: assist in releasing cell content Micro tubules go from cytoplasm to membrane then back to cytoplasm Uses about 4% of cells ATP for GH secretion Universal process in vesicle releasing cells (study several cell types across various tissues). Evidence that partial secretion can occur, not always complete as was previous thought. Calcium is required. Size of pore is related to rapidity of release Further refinement of assembly and disassembly of fusion pore. Fusion poor is embedded in membrane Very regulated process that requires considerable energy investment

    Collaboration Discussion: Current collaborations: JS & CL: ET work JS, CL, JL: dairy study JS & CL; many studies JS, CL, AB: 5 d CIDR PGF GP & BC; several studies KV & RK: collaborating JL, JS, CL; Dairy heifer work *Please send all collaborative stuff to me for rewrite Idea for future: Having symposia with producers (NCERA-57; extension focused committee; NC-1038 is not) AT: This committee does an excellent job at collaborating Repro summit at UF Integrated grant idea: *Beef cattle at different BCS prior to calving: Fat, moderate, thin: then change: up or down or no change AT: NC committees do not have to adhere to AFRI priorities. (we think) Previous rewrites included collaborative projects for some but not all persons but by time it goes thru project have been done or new info available. * no big project in last rewrite Genomics project in rewrite? Why not: state collaboration Jeff Stevenson will volunteer to write Justification: Keep same objectives  come to meeting next year with umbrella ideas Come up with a couple of folks to take leadership role & come with some ideas written up *nutrition & reproduction interactions *Include new objective on Genomic Cliff and Jeff will coordinate the rewrite AT: senior members coordinate and jr members do some of the heavy lifting LA: Does climate change pertain to this group *Should we change to Nutritional and Environmental effects on reproduction (idea from GP) Cliff is organizing a IETS pre-conference symposium (Jan. 8th-Orlando): speakers: Joe LeRoy, Steven LaBlanc, Milo Wiltbank, Buriselli, Pat Lonagren, Jeremy Block, Bill Thatcher, Round table

    Adjourn (12:00 pm)

    Accomplishments:

    Objective 1. To develop breeding programs to maximize pregnancy rates.

    Kansas State

    Injection of hCG on d 7 post-estrus (at the time of embryo transfer) induced ovulation in 69% of recipient beef cows, increased concentrations of progesterone, and increased pregnancy transfer rates by 7 percentage points.

    Injection of eCG at the time of PGF2a failed to alter progesterone concentrations or timed AI pregnancy rates. In fact, treatment of suckled beef cows with eCG at CIDR insert removal reduced timed AI pregnancy rates. Location accounted for differences in cycling status, luteolysis success, pregnancy rates, and pregnancy loss between d 35 and 67. We concluded that eCG treatment under these experimental conditions did not increase concentrations of progesterone post-eCG or pregnancy rates of suckled beef cows.

    Applying pre-timed AI injection of PGF2a and GnRH resulted in better ovulation responses to the first GnRH injection of the timed AI protocol (Ovsynch), more CL per cow at the time of PGF2a. The pregnancy outcomes are favorable but not sufficient cows have been tested to date. Future Work

    A companion eCG study is near completion in which 100 lactating dairy cows will be treated with 400 IU of eCG or saline concomitant with the PGF2a injection of the Ovsynch protocol that followed presynchronization of estrous cycles (Presynch). Cows will be scanned before the first GnRH injection of Ovsynch, just before treatment at the time of PGF2a, and at 48 and 96 h later (to assess follicle diameter and ovulation), and at 7 and 14 days after the second GnRH injection of Ovsynch (to assess size of the CL). Pregnancy diagnosis will occur at d 32 and 60 post-AI. Our hypothesis is that the FSH activity of eCG might increase estrogen biosynthesis and mitosis of granulose cells in the preovulatory follicle, thus increasing potential CL size, progesterone output from the resulting CL and pregnancy outcome.

    Complete the lactating dairy cow experiment by treating a total of 100 cows per treatment (PG-3-G vs. Presynch 10) for which blood samples and ovarian scans are done. The treatments will continue for another year to increase the number of observations for pregnancy outcomes. In addition, a field trial is planned to test the PG-3-G vs. Presynch 10 pre-timed AI systems in 3 commercial Kansas dairy farms beginning mid September 2010. At each dairy 500 cows will be treated (250 per treatment) to provide approximately 750 cows per treatment. University of Wisconsin-Madison

    Presynchronization with hCG or GnRH 7 d before initiation of Resynch did not affect synchronization rate, but that hCG increased fertility whereas GnRH tended to increase fertility compared to Ovsynch initiated 25 d after a prior TAI.

    Presynchronization with hCG increased fertility of resynchronized cows similar to that of a Double-Ovsynch Resynch protocol while reducing the interbreeding interval by 14 d.

    Development and use of a stochastic model by commercial dairy herds may facilitate selection of economically-optimal reproductive programs based on farm-specific parameters.

    Although timing of conceptus expulsion occurred 5.2 d later for INF than for PGF cows, serum PAG concentrations for INF and PGF cows decreased at a similar rate from the onset of treatment.

    Future Work

    Researchers are continuing to work on improving fertility to synchronization strategies in lactating dairy cows. South Dakota State University

    For the project: Influence of luteal regression prior to GnRH on LH pulse frequency and synchrony of follicular growth. There was a treatment (P=0.04), time (P<0.01), and treatment x time (P<0.01) interaction on progesterone concentrations. PG-No CIDR had decreased concentrations compared to PG-CIDR and 7d CIDR, which were similar.

    There was a tendency (P=0.09) for LH pulse frequency to be greater among PG-CIDR (3.4±0.24) and PG-No CIDR (3.4±0.24) compared to the 7d CIDR (2.6±0.40), but area under the curve (P>0.76) and mean LH concentrations (P>0.76) did not differ.

    Follicular growth rates did not differ between treatments (P>0.14), but there was a tendency for decreased variance in growth rate among PG-CIDR (0.03) compared to PG-No CIDR (P = 0.1; 0.10) and 7d CIDR (P = 0.06; 0.20).

    In addition, variance in dominant follicle size on d 0 was decreased in PG-CIDR (0.2) compared to PG-No CIDR (P < 0.01; 7.8) and 7d CIDR (P = 0.01; 5.1).

    For the project: Influence of initiating luteal regression prior to treatment with GnRH on fixed time AI fertility in beef heifers. Pregnancy success was 42% (115/265) for the 5-day CIDR and 64% (162/252) for the PG-CIDR. There were no differences (P > 0.10) between sires or technicians.

    For the project: Influence of initiating luteal regression prior to treatment with GnRH on ability to control follicular waves. When all cows were included there was no difference (P = 0.43) in the percentage of cows that ovulated in response to cysterolin or factrel (77% 41/53 vs. 71% 36/51). When only cows with follicles greater than 10 mm in diameter were included there was no difference (P = 0.40) in the percentage of cows that ovulated in response to cysterolin or factrel (82% 41/50 vs. 75% 36/48). More cows (P = 0.03) treated with the PG-CIDR protocol ovulated following the GnRH injection compared to the 5-day CIDR protocol when all cows were included [83% (43/52) and 64% (34/53); respectively). When only cows with follicles > 10 mm in diameter were included more (P = 0.03) PG-CIDR treated cows ovulated following the GnRH injection compared to the 5-day CIDR protocol [88% (43/49) and 69% (34/49); respectively). Among heifers when all were included there was no difference (P = 0.51) in the percentage that ovulated in response to cysterolin or factrel (44% 8/18 vs. 56% 10/18). When only heifers with follicles greater than 10 mm in diameter were included there was no difference (P = 0.61) in the percentage that ovulated in response to cysterolin or factrel (53% 8/15 vs. 63% 10/16). There was no difference in ovulatory response between heifers treated with the 7-day CIDR protocol or the PG-CIDR protocol [44% (8/18) vs. 56% (10/18) for all heifers respectively and 53% (8/15) vs. 63% (10/16) for heifers with > 10 mm respectively].

    Future Work

    To investigate why some follicles do not ovulate in respone to an injection of GnRH.

    Mississippi State University

    Preliminary data indicate that replacing the first injection of GnRH with hCG in the Double-Ovsynch protocol does not affect conception rates in heifers (30.8 and 36.2%, respectively) or cows (23.4 and 23.0%, respectively). However, the number of CLs present on d 7 after treatment was increased (P < 0.05) in heifers (0.9 and 1.4) and cows (1.2 and 1.8) treated with hCG.

    Additional data are being collected to determine the effects of the presence of either a vasectomized bull or a sidewinder bull during the 21 days prior to AI.

    Future Work

    Additional data will be collected on Experiments 1 and 2 in this report. These two experiments will be repeated this coming fall. Additionally, a collaborative project with Drs. Stevenson and Lamb will be conducted this fall in dairy heifers to evaluate a 5-day CIDR protocol for synchronization of the estrous cycle. A collaborative project with Drs. Lamb and Dahlen will be conducted this fall and spring to evaluate a 72-hour calf removal protocol on conception rates as well as calf growth. Research will be conducted to evaluate the timing of insemination when using sex-sorted semen.

    Purdue Station Report

    Delivering PGF2a at CIDR insertion did not increase timed-AI pregnancy rates in replacement beef heifers.

    Using a CIDR insert three times in the 5 d CIDR protocols is feasible as circulating concentrations of progesterone remain greater than 1.0 ng/mL suggesting sufficient progesterone to prevent estrous and ovulation.

    Feeding DDGS as an energy source during late gestation and early in the postpartum period can impact fetal growth and result in increased calving difficulties. However, no negative impacts on reproductive performance were observed.

    Future Work

    Determine the impact of gonadotropin stimulation and follicle age on oocyte viability and competence.

    Impact of excessive CP supplementation on oocyte competence and early embryonic development

    Continue investigations into developing new and effective timed-AI protocols for beef heifers.

    Assessment and validation of molecular genetics tools for selection of replacement beef heifers. Objective 2: To characterize physiological mechanisms that regulate ovarian and uterine functions.

    Iowa State University

    Cellular protein transport and secretion is fundamental to the very existence of an organism, regulating important physiological functions such as reproduction, digestion, energy production, growth, neurotransmission, hormone release, water and ion transport, et cetera, all required for the survival and maintenance of homeostasis within an organism. Molecular understanding of transport and secretion of intracellular product, has therefore been of paramount importance and aggressively investigated for over six decades. Only in the last 20 years, the general molecular mechanism of the process has come to light, following discovery of key proteins involved in ER-Golgi transport, and discovery of the porosome the universal secretion machinery in cells.

    In cattle luteinizing hormone (LH) is released in a pulsatile pattern that depends on age, reproductive stage of the estrous cycle, pregnancy and postpartum and effects of other factors, i.e., leptin, nalaxone (an opiate antagonist, neuropeptide-Y). This indicates LH release is regulated by hypothalamic gonadotropin-releasing hormone (GnRH). Estradiol treatment induces a preovulatory LH surge in cattle presumably by increasing pituitary sensitivity of hypothalamic GnRH and subsequent GnRH release. We hypothesize that neurosurgical isolation of the medial basal hypothalamus in beef heifer calves differentially affects estrogen-induced LH secretion. Results from this research indicate that there is a transient change in LH secretion after anterior hypothalamic or complete hypothalamic deafferentation in prepuberal heifers with intact ovaries. The integrity of the neural connection of the posterior hypothalamus is required for estrogen-induced LH release in beef heifers

    University of Kentucky

    Future Work

    Further studies will be conducted to determine if the timing of insemination can be optimized through the use of devices designed to sense core body temperature and motion. We will focus on accelerometer patterns during mounting events.

    University of Illinois

    Invited lecture: Towards use of microfluidics for individual embryo culture. January, 2010. International Embryo Transfer Society Annual Meeting, Cordoba, Argentina.

    Researchers have validated our gene expression results with functional studies which demonstrate that cellular redox pathways play a major role in porcine oocyte quality.

    Researchers have characterized the Ossabaw mini-pig as a valuable model of polycystic ovary syndrome (PCOS), which may be used to study the disease mechanisms and ART applications.

    Researchers have determined that leptin and glucose interact during oocyte maturation to affect oocyte quality in conditions of obesity.

    Future Work

    Scientists continue to examine oocyte competency, develop our novel model for PCOS and elucidate the effects of obesity on ovarian steroidogenesis and oocyte quality. We plan to focus, in particular, on cellular redox pathways in the oocyte, how gene expression and pathway function is affected by multiple models of oocyte competence, and how this information can be used to influence oocyte quality after in vitro maturation.

    USDA-ARS U.S. Meat Animal Research Center

    Ultrasonographic measurements of the number of antral follicles, size of the ovaries, and diameter of the uterine horn in yearling heifers will be useful phenotypes in whole genome scans for identifying genetic markers of heifer fertility.

    Clustering analysis and pathway determination of genes involved in ovarian function and adiposity will aid in fine mapping functional polymorphisms that influence heifer fertility.

    Future Work

    Moving forward in the Germplasm Evaluation Project, yearling heifers (n = 1000/year beginning in 2010) will be evaluated for antral follicle counts, ovulatory status, ovary length and height, and uterine horn diameter. Genotypes will be determined using a combination of the 770K SNP Chip and the 50K SNP Chip. Measurements of adiposity, fatty acid profiles, and adipose RNA-sequencing will be included in evaluations of heifer development and fertility. Ovarian cortex from repeat-breeder and control cows will be submitted for RNA-sequencing to identify genes controlling the size of the ovarian reserve and ovarian development.

    South Dakota State University

    Uterine expression of Na+/H+ antiporters 1, 2, and 4 in beef cows following CIDR removal. Onset of estrus was determined by the HeatWatch Estrous Detection System from d 0 to d 5, and mean interval to estrus was 70.48 ± 1.74 h. There was no effect of estrus on expression of Na+/H+ antiporter 1, 2, or 4 (P = 0.43, 0.33, and 0.88, respectively). In addition there was no effect of time (P > 0.25, respectively), on expression of antiporter 4. Alternatively, there was an effect of time (P < 0.05 and P = 0.04) on antiporter 1 and 2 expression, and an estrus by time interaction (P = 0.05, P < 0.01, and P < 0.04, respectively) on expression of antiporter 1, 2, and 4. Among cows that exhibited standing estrus, expression of antiporter 1 was decreased at 48 h compared to h 0 (P = 0.05), antiporter 2 expression was decreased at 12, 24, 36, 48, and 60 h compared to h 0 (P < 0.01), and antiporter 4 expression was decreased at 36, 48, and 60 h compared to h 0 (P < 0.02). Among cows that did not exhibit estrus, expression of antiporter 1, 2, and 4 did not change (P > 0.14, P > 0.35, and P > 0.06; respectively).

    Effect of ovulatory follicle size on luteal weight and steriodogenic enzyme expression. Cows that exhibited estrus tended (P=0.09) to have larger follicles than cows that did not exhibit estrus (15.3±0.8 and 13.7±0.4), but there was no difference (P=0.99) in d 10 luteal weight (5.0±0.7 and 5.0±0.4). Ovulatory follicle size tended (P=0.056) to have a positive correlation with luteal weight on d 10 (R-squared 0.18). For every one mm increase in ovulatory follicle size, d 10 luteal weight increased by 0.33 g. When ovulatory follicle size was grouped into small (<12 mm), medium (12-15.5 mm), and large (>15.5 mm) follicles, follicle size (P=0.04) and time (P<0.01) influenced concentrations of progesterone, and there tended to be a follicle size by time interaction (P=0.08). However, there was no effect of estrus (P=0.16), luteal weight (P=0.47), estrus by time (P=0.21), or luteal weight by time (P=0.50) interaction on circulating concentrations of progesterone. In addition, there was no effect of estrus, follicle size, or luteal weight on LH receptor expression (P=0.99, 0.87, and 0.85, respectively), StAR expression (P=0.35, 0.70, and 0.16, respectively), CYP11A1 expression (P=0.64, 0.74, and 0.69, respectively), or 3b-HSD expression (P=0.39, 0.11, and 0.69, respectively).

    Future Work

    To investigate the regulation of Na+/H+ antiporter and distribution of cell populations in CLs following GnRH induced ovulation.

    Ohio State University

    found that SVCT1 mRNA was not amplified to measureable levels during the standard curve validation. It is likely that there was limited SVCT1 message available for amplification. Certain tissues within the body are preferentially biased toward one specific SVCT transporter over another. We speculate that the CL may be one such tissue, and preferentially biased toward SVCT2. Further tests using a known SVCT1 biased tissue will be needed to confirm if this is true.

    SVCT2 was amplified to measureable concentrations during the standard curve validation (Fig.2.) Real time PCR of logarithmic serial dilutions of RNA resulted in a dose-dependent increase in the number of cycles needed to reach threshold (CT). To be valid, at least three of these dilutions need to have a consistent interval between CT values. We validated SVCT2 amplification by observing four consistent intervals corresponding to RNA concentrations of 200, 20, 2, and 0.2 ng/well.

    In the early luteal phase there was no effect of PGF2± treatment, or hour of collection, on the concentration of SVCT2 mRNA (Fig. 3). There was a significant increase in concentration of SVCT2 message as the CL aged from early to mid cycle (p< 0.01). PGF2± had no effect on mid cycle CL at 2h, but tended to decrease the concentration of SVCT2 mRNA at 24h (p=0.06).

    North Dakota State University

    Maternal diet can regulate progesterone catabolism and may impact fertility Maternal diet appear to influence uterine blood flow to the developing calf. Future Work: To determine the impacts of nutrition, specifically duration of undernutrition, during pregnancy on placental vascularity and vasoactivity, as well as offspring growth and reproductive development will be assessed.

    Impact Statements:
    1. Increased ET pregnancy rates of 7.9% in response to hCG administration should lead to increased profits. When treating 100 recipient cows with hCG, an approximate 8% increase in pregnancy rates could provide 8 additional calves. The dosage used in this study (1,000 IU) cost US$2.62 per recipient. Administration of 1,000 IU hCG to 100 recipients cost $262.00 (100 recipients × $2.62/dose). The cost of each of additional calf would be $32.75 ($262/8 calves), which is relatively inexpensive considering the costs associated with maintaining a recipient.
    2. Results from current and ongoing research have been used to make recommendations to stakeholders and their consultants regarding implementation of systematic synchronization and resynchronization systems for lactating dairy cows as well as timing and methods for pregnancy diagnosis. Data generated in these projects has been published in scientific journals and included in numerous extension proceedings.
    3. Through reduced days open and genetic improvement (widespread use of artificial insemination), improved efficiency of estrus detection will increase farm income by increasing milk production. The increase in milk production is conservatively valued at $100/cow.
    4. An increased understanding of the mechanisms that impart oocyte quality will allow us to design estrous synchronization and superstimulation protocols, as well as in vitro maturation systems, to best support high oocyte quality, resulting in increased reproductive efficiency.
    5. Expression of Na+/H+ antiporter 1, 2 and 4 appears to have a significantly impact on the regulation of uterine pH around the onset of estrus.
    6. Researchers have a better understanding of the regulation of ovarian ascorbate, increased knowledge of the role of ascorbate in reproduction, and utilize this information to better manipulate and enhance reproduction in various species. The results from this research bring the research community one step closer to understanding the potential role of ascorbic acid transport proteins in the sheep.
    Last Modified: 13-Dec-2010

    Date of Annual Report: 08/24/2011

    Report Information:
  • Annual Meeting Dates: 08/10/11 to 08/11/11
  • Period the Report Covers: 10/2010 to 09/2011

    • Participants:
    Brief Summary of Minutes of Annual Meeting:
    Participants:

    Bridges, Allen - University of Minnesota

    Cushman, Robert - USDA, ARS, USMARC

    Fricke, Paul - University of Wisconsin

    Lamb, G. Clifford - University of Florida

    Perry, George  South Dakota State University

    Stevenson, Jeffrey  Kansas State University

    Vonnahme, Kimberly  North Dakota State University

    Dahlen, Carl  North Dakota State University

    Larson, Jamie - Mississippi State University

    Funston, Rick - University of Nebraska

    Ravlin, Bill  The Ohio State University and Administrative Advisor

    Brief Summary of Minutes of Annual Meeting:

    Wednesday, August 10

    Introductions and registration. Registration is $20/person. Station Reports were distributed electronically, either before or during the meeting.

    Station reports were given by:

    University of Wisconsin

    North Dakota State University. Dr. Lardy (head, Department of Animal Science) joined the group and gave a brief welcome and answered questions regarding NDSU, etc.

    Resumed station reports:

    Mississippi State University

    USDA, ARS USMARC

    University of Nebraska

    South Dakota State University

    Kansas State University

    University of Minnesota

    Completed Station reports shortly after noon.

    Lunch

    Administrative report by Bill Ravlin

    Budget cuts are proposed/expected; 16.7% proposed cut to NIFA by the house, also cuts to AFRI and Hatch funds are proposed.

    Ideas for responding to fewer funds from traditional sources. Diversify and be more competitive Attacking societal issues

    Below is the most recent information coming out of the system related to the House budget. (I've included the entire e-mail sent to me so you can get a feel for the discussion.) Note that the actual budget information/spreadsheet is at: http://www.land-grant.org/docs/FY2012/Hse.xlswww.land-grant.org/docs/FY2012/Hse.xls

    In addition, the new NC Proposal Development project may be of interest and the Battelle study can be found at: NCRA.info

    Finally, please look over the Science Roadmap for Food and Agriculture (escop.ncsu.edu/docs/scienceroadmap.pdf) with an eye toward issues that relate to reproductive efficiency.

    The impact analysis by the Battelle group of the North Central Region was briefly discussed and can be found at NCRA.info

    There is also funding for multi-state grants by North Central region for proposal development This is the year for the NC-1038 rewrite. The rewrite is due to Bill Ravlin by December 1, and will be voted on in March at the Experiment Station meeting.

    Strategy for the rewrite was discussed by Jeff and Cliff Need a statement of issues Title - recommended change Impacts

    What needs to be completed? Objectives, Methods, individual and multi location contributions, publications and grants

    Possible Objectives Pre and post nutritional management strategies that impact reproduction 5 d vs. Presynch 5 d CO-Synch (dairy) Targeted estrous synchronization protocols based on calving date Duration of CIDR study Uterine environment and embryo survival

    Provide information from each location to Cliff

    Business meeting

    New officers were discussed for next year.

    Chair will be Rick Funston

    Secretary will be Jamie Larson

    Member at large will be Carl Dahlen

    Meeting location was discussed, Jamie suggested IACR in Vancouver, Cliff suggested Panama City, however, because of budget uncertainties it was decided to have the meeting in a less expensive place. Kansas City was decided and the dates will be September 11-12 somewhere near the airport. Jeff Stevenson will handle local arrangements.

    Discussion of collaborative projects will be an agenda item.

    Meeting was adjourned for the day

    Tour of new NDSU feeding facility

    Thursday, August 11

    Morning was spent on rewrite of the new project. All locations provided information to Cliff and Cliff placed in a master document. Groups were assigned to work on specific sections. A working document and Appendix A was assembled and Cliff distributed for final comment. Comments are due back to Cliff by August 19, 2011.

    Meeting adjourned.

    Submitted by:

    Rick Funston NC-1038 Secretary

    Accomplishments:
    Objective 1: To develop breeding programs to maximize pregnancy rates

    Florida Agricultural Experiment Station

    This station determined that calf removal reduced the interval to the LH peak and both calf removal and use of equine chorionic gonadotropin at CIDR removal enhanced follicle growth, ovulation incidence, and P4 concentrations in early postpartum suckled beef cows. However, calf removal did not appear to enhance pregnancy rates in suckled beef cows when exposed to 48 or 72 hr calf removal, but subsequent calf performance was negatively affected by calf removal. A once-used CIDR developed more persistent follicles than new CIDR, whereas follicular aspiration was more effective at follicle turnover than an additional CIDR or saline treatments.

    Developing heifers using perennial peanut hay results in similar performance to heifers that were developed on a grain-based diet and greater performance than heifers that did not receive a supplement. In addition, heifers receiving a perennial peanut hey supplement had greater pregnancy rates than those heifers that received no supplement. Puberty was attain earlier during the breeding season in supplemented (perennial peanut or grain-based supplemented heifers) than those that did not receive a supplement.

    Future Work

    Additional research will be performed to validate the efficacy of estrus synchronization and fixed-time artificial insemination protocols in production settings, specifically addressing follicle health at fixed-time AI to reduced variability in pregnancy rates among locations.

    Current studies have been initiated to determine whether estrous cycles may be effectively synchronized in heifers to induce an ovulatory follicle that grows in the absence of exogenous progesterone.

    Kansas Agricultural Experiment Station

    Treatment of lactating dairy cows with hCG on d 7 post-AI increased concentrations of progesterone following hCG-induced ovulation of ovarian follicles, but failed to improve pregnancy rate.

    Retention of original CL through d 28 after AI in cows diagnosed not pregnant on d 32 was associated with increased concentrations of pregnancy-specific protein B, a marker for pregnancy. These results indicate that cows having long cycles after AI may be associated with pregnancy, CL retention, and early embryonic loss.

    Presynchronization of estrous cycles in cows by applying PGF2± (PG) followed in 3 d by GnRH (PG-3-G) and initiating Ovsynch 10 d after PGF2± resulted in greater ovulation rates, elevated progesterone, and more cows having a CL at the onset of the Ovsynch protocol than cows assigned to Presynch-10. Pregnancy rates tended to be greater in the 210-cow study. Application of PG-3-G in 3 additional commercial dairy herds tended to improve pregnancy rates in 2 of 4 herds.

    Future Work

    A study is planned to examine LH concentrations in response to GnRH injections associated with presynchronization protocols and during application of Ovsynch.

    Results are being compiled for a multi-location study in suckled beef cows in which a presynchronizing injection of PGF2a was administered 3 d before initiating a 7-d CO-synch + CIDR protocol.

    A resynchronization study in lactating dairy cows is ongoing in which open cows are submitted to a 5-d Ovsynch with and without a CIDR insert.

    Mississippi Agriculture & Forestry Experiment Station

    During the course of the past year, this station initiated three experiments which are outlined below.

    Experiment 1 provided data to support that while hCG at the initiation of Double-Ovsynch induced more ovulations than GnRH, more of the CLs that developed as a result of ovulation from hCG failed to undergo luteolysis from PGF2± and thus conception rates were similar between treatments.

    Experiment 2 provided data indicating that the presence of a sidewinder bull caused more heifers to display estrus after estrus synchronization compared to other treatments and heifers and cows exposed to a sidewinder bull achieved increased conception rates compared to females exposed to a vasectomized bull, with the control group intermediate. Conclusions from this experiment alone do not justify the added cost and management of maintaining sidewinder bulls to enhance fertility, although more research into effects of bio stimulation on fertility is needed.

    Experiment 3 provided evidence that sex-sorted semen can be used in beef heifers and cows with the expectation that a similar decrease in fertility will occur as it does in dairy heifers. Select beef cows could be good candidates for receiving sex-sorted semen.

    Future Work

    Data from a collaborative project with Drs. Stevenson and Lamb evaluating a 5-day CIDR protocol in dairy heifers is currently being analyzed and prepared for publication. A collaborative project with Drs. Lamb and Dahlen to evaluate a 72-hour calf removal protocol on conception rates as well as calf growth is currently being conducted. Research will be conducted in dairy cows to evaluate impacts of changes in body condition, glucose, NEFA, leptin, etc. at the time of conception on fetal growth and heifer calf performance.

    North Dakota State University

    During the course of the past year, this station initiated three experiments which are outlined below.

    Experiment 1 provided data that reveled melatonin may negate the consequences of IUGR during specific abnormalities in umbilical blood flow as long as sufficient uterine blood perfusion is maintained during the pregnancy.

    Experiment 2 provided data indicating that although maternal re-alimentation after nutrient restriction did not affect uterine BF percentage change, maternal diet affected PI and RI percentage change. Further investigations in uterine and placental vascular reactivity may help explain the differences observed in resistance indices.

    Experiment 3 indicated that although maternal diet restriction during early to mid-gestation did not affect umbilical blood flow, there was evidence to indicate that it may alter fetal cardiac output.

    Future Work

    Continue to work models of nutrient restriction and the subsequent effects on uterine and umbilical blood flow. Elucidate mechanisms responsible for alterations in uterine/umbilical blood flow and use knowledge of these factors to bring concepts of developmental programming research to the applied/producer level. A collaborative project with Drs. Lamb and Larson to evaluate a 72-hour calf removal protocol on conception rates as well as calf growth is currently being conducted. In addition, a long term project was initiated to evaluate the impact of utilizing AI and estrous synchronization in commercial beef operations.

    South Dakota State University

    This stations research showed that:

    45% (72/159) of all heifers exhibited standing estrus between the injection of PGF2a and insertion of the CIDR.

    There was no difference (P = 0.77) between heifers with concentrations of progesterone > 1 ng/mL on d -9 (d of PGF2a; 44%, 47/107) and heifers with concentrations of progesterone < 1 ng/mL on the d-9 (47%, 21/45) in the percentage of heifers that exhibited estrus between PGF2a and CIDR insertion.

    There was no difference (P = 0.78) in BCS between heifers that did and did not exhibit estrus (5.9 ± 0.1 and 5.9 ± 0.1, respectively).

    Interval to estrus following CIDR removal did not differ (P = 0.18) between heifers that did (n = 72) and did not (n = 87) exhibit estrus before CIDR insertion (51.8 ± 1.0 and 53.6 ± 1.0 h, respectively). However, variance for the interval to estrus tended to differ (P = 0.07) between heifers that did (47.5) and did not (76.0) exhibit estrus before CIDR insertion.

    Future Work

    To investigate why some follicles do not ovulate in response to an injection of GnRH.

    University of Minnesota

    Administering two concurrent 25 mg doses of PGF is an effective method of PGF delivery when conducting the 5 d CO-Synch + CIDR protocol in lactating beef cows.

    Feeding elevated amounts of DDGS during the third trimester of pregnancy to pregnant cattle impacted growth performance of female offspring and marginally impacted rate of sexual maturation.

    Reducing nutrient inputs and subsequently body condition score of cows during the postpartum period can impact follicular growth and CL diameter. Likewise, reduced nutrition reduces the yield of quality embryos following ovarian super-stimulation. However, it is still unclear how or if such parameters impact fertility and if a suppression if nutrition has an impact on uterine function and/or oocyte competence.

    Future Work

    Evaluation of follicular microenvironment, oocyte viability, and oocyte and granulosa cell gene expression in beef cows on varying planes of nutrition.

    Embryo yield and quality of FSH-stimulated donor cows with differing concentrations of progesterone during follicular development.

    Determining if deliver of prostaglandin F2alpha to anestrous cows prior to the onset of estrous synchronization impacts the LH surge, response to GnRH, follicular growth, and fertility.

    Compare timed-AI pregnancy rates in beef heifers synchronized with either the 5-day CO-Synch + CIDR, PG 6-d CIDR, or 14-d CIDR-PG protocol.

    University of Nebraska

    Low input heifer development systems result in acceptable AI and final pregnancy rates.

    Late gestation supplementation of cows grazing winter range or corn residue impact subsequent steer and heifer progeny performance.

    Future Work

    Additional research will be conducted to further elucidate mechanisms by which strategic supplementation around the time of breeding may impact reproduction. Heifer development research will continue to determine if heifers development in low input systems are more efficient and adapt to grazing crop residue more readily. A project has been initiated to control for fetal age and sire and determine amount of supplementation needed to prevent a negative impact on the fetus when cows graze dormant range. This study will also examine the impact of early or late weaning on supplementation needs.

    USDA-ARS U.S. Meat Animal Research Center

    This station conducted a series of studies to evaluate how genetic background and post-weaning nutrition influence development of the reproductive tract in the heifer. Breed differences in antral follicle counts suggests that there are genes controlling the differences in this phenotype and supports continued efforts to identify genes influencing reproductive fitness.

    Wisconsin Agricultural Experiment Station

    Resynchronized lactating cows that had high P4 at G1 and that ovulated after G1 had an increased synchronization rate resulting in increased fertility to TAI.

    Circulating P4 reduces GnRH-induced LH secretion, and a higher dose of GnRH can increase LH secretion both in a high and low P4 environment.

    Development and use of a stochastic model by commercial dairy herds may facilitate selection of economically-optimal reproductive programs based on farm-specific parameters.

    Presynchronization with GnRH 7 d before initiation of Resynch increased fertility of resynchronized dairy cows whereas timing of initiation of Resynch did not.

    Some but not all lactating dairy cows developed an Ab response after repeated exposure to hCG and that maximum response is observed within 14 d of hCG injection.

    Future Work

    This station is continuing to work on improving fertility to synchronization strategies in lactating dairy cows.

    Objective 2: To characterize physiological mechanisms that regulate ovarian and uterine functions

    Florida Agricultural Experiment Station

    This station determined that calf removal reduced the interval to the LH peak and both calf removal and use of equine chorionic gonadotropin at CIDR removal enhanced follicle growth, ovulation incidence, and P4 concentrations in early postpartum suckled beef cows. However, calf removal did not appear to enhance pregnancy rates in suckled beef cows when exposed to 48 or 72 hr calf removal, but subsequent calf performance was negatively affected by calf removal.

    A once-used CIDR developed more persistent follicles than new CIDR, whereas follicular aspiration was more effective at follicle turnover than an additional CIDR or saline treatments.

    Developing heifers using perennial peanut hay results in similar performance to heifers that were developed on a grain-based diet and greater performance than heifers that did not receive a supplement. In addition, heifers receiving a perennial peanut hey supplement had greater pregnancy rates than those heifers that received no supplement. Puberty was attain earlier during the breeding season in supplemented (perennial peanut or grain-based supplemented heifers) than those that did not receive a supplement.

    Future Work

    Additional research will be performed to validate the efficacy of estrus synchronization and fixed-time artificial insemination protocols in production settings, specifically addressing follicle health at fixed-time AI to reduced variability in pregnancy rates among locations.

    Current studies have been initiated to determine whether estrous cycles may be effectively synchronized in heifers to induce an ovulatory follicle that grows in the absence of exogenous progesterone.

    Kentucky Agricultural Experiment Station

    Future Work

    Further studies will be conducted to determine if the timing of insemination can be optimized through the use of accelerometer devices designed to sense motion. We will focus on accelerometer patterns during mounting events. The utility of accelerometer based insemination versus a timed insemination protocol (G6G, Ovsynch 56, Resynch) will also be examined.

    South Dakota State University

    There was a treatment, time, and treatment by time interaction (P < 0.01) on PUN concentrations. On d 1, approximately 7 h after the dietary treatments were first fed, concentrations of PUN were greater in N and NS compared to C (P < 0.01 and P = 0.02, respectively) and S (P < 0.01 and P = 0.02, respectively). Starting on d 3, PUN concentrations were increased in N and NS, which were not different (P > 0.05), compared with C and S (P < 0.01), which were not different (P > 0.05).

    There was an effect of treatment (P < 0.01) on sulfate concentrations, with concentrations being increased in S compared with C, N, and NS (P < 0.01), with NS increased compared to C (P < 0.01) and N (P < 0.01). In addition, sulfate concentrations were increased on d 4 compared to d 8 (P = 0.04) and 16 (P < 0.01) and were decreased on d 8 and 16 compared to d 24 (P = 0.01 and P < 0.01, respectively) and 27 (P < 0.05 and P < 0.01, respectively), but there was no treatment by time interaction (P = 0.81).

    There was no effect of treatment (P = 0.55) or a treatment by time interaction (P = 0.16) on progesterone concentrations, but there was an effect of time (P < 0.01), with increasing concentrations after estrus consistent with normal CL formation.

    Uterine pH was increased in N and NS compared to C (P < 0.02), while S was not different from any treatment (P > 0.11). There was no effect of time (P = 0.26) or treatment by time interaction (P = 0.71) on uterine pH.

    Future Work

    To investigate the impact of elevated PUNs of pregnancy success.

    USDA-ARS U.S. Meat Animal Research Center

    A series of studies applying molecular genetics and functional genomics identified candidate genes influencing fertility in cattle.

    Future Work

    A study is planned to examine genetic variation in the response to prostaglandin F2. Transciptomic analysis will identify genes that are differentially expressed in the uterus, ovary, and liver of heifers raised under different developmental programs.

    Impact Statements:
    1. Research proved that heifers developed on perennial peanut have similar weight performance and reproductive performance to heifers receiving a grain-based development supplement, but improved growth and reproductive performance compared to non-supplemented controls. Therefore, development of heifers on high quality legumes should be able to replace expensive grain-based supplements with legume hay during heifer development with little impact on heifer development outcomes, which results in less cost for feed.
    2. NC-1038 scientists show that nutrient composition of diets fed to gestating cows may impact the future growth potential and production efficiency of their offspring. Feeding elevated amounts of crude protein results in heavier calves at birth, greater frame scores at weaning, and greater weaning weights. Therefore, developing a greater understanding on developmental programming and how to utilize the concept of developmental programming in production settings will likely provide an avenue to increase production efficiency in the beef cattle industry.
    3. Studies at this experiment station prove that low input heifer development systems have resulted in a $100/head savings per pregnant heifer over conventional heifer development systems.
    4. Scientists showed that with the supplementation of pregnant cows grazing winter range or crop residue net a result in a $125 increase in net return of steers fed to harvest.
    5. Improved efficiency of estrus detection will increase farm income by increasing milk production, through reduced days open and genetic improvement (widespread use of artificial insemination). The increase in milk production is conservatively valued at $100/cow.
    Last Modified: 26-Sep-2011

    Date of Annual Report: 09/17/2012

    Report Information:
  • Annual Meeting Dates: 09/11/12 to 09/12/12
  • Period the Report Covers: 10/2011 to 09/2012

    • Participants:
    Brief Summary of Minutes of Annual Meeting:
    Kansas City, MS-9/11-12/2012

    Attendance: Rick Funston, Jeff Stevenson, George Perry, Cliff Lamb, Dave Patterson + 2 students, Allen Garverick, Carl Dahlen, Jamie Larson, Paul Fricke, Hassan Khatib, Teresa Steckler, Bill Ravlin

    Called to order at 8:00 AM by Rick Funston Registration will be $27 per station for lunch and meeting room.

    Station Reports (see individual station reports for research details):

    Jeff Stevenson  Kansas State University Good discussion on Jeffs project #3 involving hCG in presynch as well as about the retained CL and P4 in cows that are not pregnant at d 35. Good discussion on Angus cattle and the increase in age at puberty, increase in growth, reduction in numbers of sires used and decrease in fertility.

    Cliff Lamb  University of Florida Discussion about AI vs. natural mating study and how that has changed even with 2012 numbers. Discussion on calf removal study, why are younger and older calves affected negatively more than medium-aged calves?

    Paul Fricke  University of Wisconsin Discussion about timing of AI in the accelerometer systems, what causes you to breed too early or too late. Timing of ovulation relative to start of standing estrus.

    Jamie Larson  Mississippi State University Discussion on the commercialization of AMH and reliability of the assay.

    Carl Dahlen  North Dakota State University Discussion on analysis of the natural service vs. TAI project, long term implications, etc. Discussion of the postcard survey and plans for dissemination of information.

    Dave Patterson  University of Missouri Discussion of their new program, Missouri Beef Project, which is just getting started but has some strong potential within the industry.

    Discussion of BSEs&shortage of veterinarians willing and capable of doing exams, a lack of producers doing legitimate exams, more bulls that dont produce freezable semen.

    Teresa Steckler  University of Illinois Discussion of BSEs and animal use. Injection site lesions and BQA.

    George Perry  South Dakota State University Discussion of treatment assignments of treatment based on age and BCS, assignment based on cyclicity when treatments differ in duration?? Discussion of E2 project, implications and further research.

    Rick Funston  University of Nebraska

    Bob Cushman  USDA MARC and Allen Bridges  University of Minnesota submitted electronic reports to the committee ahead of the meeting.

    Bill Ravlin  Administration update

    Bill commended us on our rewrite efforts. Our rewrite was clean and clear and easy to read. He commended our leadership and the fact we stayed longer last year to get it done.

    Bill discussed funding coming down the pipeline. He mentioned that USDA may be moving towards smaller dollar amount awards in an effort to make more awards. Also mentioned discussion in Congress to enact matching fund requirements. Would products, animal usage, and salary be considered matching funds? Details and whether this will be enacted is yet to be determined.

    Discussion regarding Small Farms granting opportunities and the ties to organic or anti other non conventional operations. How do we fit what we do into available funding mechanisms? Differences in funding amounts to plants vs. animals, will that change? Message has been communicated but we dont know if anything will change.

    Adele Turzillo  USDA update (report submitted electronically before meeting)

    Personnel updates: New director of NIFA, new program director for genetics section, expecting new poultry director. Some other changes listed on Adeles report.

    Combined 2012/2013 Foundational RFAs, RFAs expected out in October. The Integrated RFAs expected later this fall.

    Budget: See report for expected changes. Expect a one-year extension on current farm bill rather than approval of a new farm bill. Adele does not see any major changes in upcoming integrated vs. foundation funding and how they fit into the challenge areas. Doesnt expect new NIFA director to make major changes.

    Business Meeting

    2013 meeting scheduled for September 10-11, 2013. Location is Omaha. Jamie will take care of arrangements.

    Carl will be the 2013 secretary.

    Discussion of collaborative projects

    Objective 1:

    Impact of maternal environment on progeny

    Bob looking for phenotypic related data and blood sample from cows we are measuring pregnancy rate, age at puberty, age at first calving, time from lutalyse to estrus, antral follicle count, postweaning ADG, birth weight, follicle diameter. He needs any treatments applied and management/dietary things but as long as we can get him the blood samples he can do the DNA work.

    Bob doing an experiment with the following design, hell have additional tissues that are up for grabs:

    Wean -210, bleed -150, US -60, US -30, PGF1 -11, PGF2 0, 16 slaughter/AFC

    George described some of his work relating nutrition and reproduction. Discussion of complexities of measuring nutritional status of grazing animals and things to measure in blood to assess nutritional status.

    Hassan discussed potential project involving putting split embryos into two dams, one on high starch and one on low starch. At birth, offspring slaughtered and tissues analyzed for gene expression. Carl described a project at NDSU involving nutrient restriction in early gestation and then realimentation during later gestation. Serial slaughters during gestation will take place to assess various tissues.

    To examine the use of new technologies to assist with enhancing reproductive performance

    Discussion of accelerometer systems and their potential use for not only reproductive management but also rumination/health status. Concerns over the idea that some are pushing these systems as an alternative to hormonal synchronization and instilling fear that the hormones are bad and will go away.

    Objective 2:

    Reproductive management of&

    Cliff proposed a project and is looking for additional animal numbers for the following protocol:

    Blood -20, blood -10 CIDR insertion with GnRH with or without PGF, -3 CIDR removal and PGF, 0 TAI and GnRH, 35 and 65 preg check

    Cliff, Jeff, Teresa, George, Jamie all interested in contributing animals.

    Paul proposed a potential project in dairy animals comparing the 5 day with 2 injections of PGF to the 7 day with 2 injections of PGF. Jeff, Paul, and Jamie will discuss further.

    Meeting adjourned at 11:15.

    Accomplishments:
    OBJECTIVE 1. To elucidate mechanisms regulating reproductive efficiency in cattle

    Accomplishments/Outputs

    South Dakota State University

    -Serum estradiol concentrations during the simulated preovulatory period were different (P < 0.01) between treatments. -Transrectal ultrasonography on d 29 revealed pregnancy rates of 21%, 29%, and 4% for the ECP, EB, and CON treatments, respectively. This indicated substantial pregnancy loss between d 7 and d 29. -Exposure to estradiol in the preovulatory period, whether in the ECP or EB treatment increased the odds of pregnancy at d 29 (P < 0.05). -Heifers with activated patches at time of CIDR insertion had increased pregnancy success compared to heifers with partially activated patches (P = 0.01) and tended to have increased success compared to heifers with non-activated patches (P = 0.06). -Heifers with activated patches at time of fixed-time AI had increased pregnancy success compared to heifers with partially activated (P=0.03) and not activated patches (P < 0.01). -Based on d -6 patch activity, there was no difference (P = 0.16) in the percentage of heifers with elevated concentrations of progesterone (> 1 ng/mL) on d -9, but the percentage of heifers with elevated concentrations of progesterone (> 1 ng/mL) on d -6 did differ (P < 0.01) between heifers with activated, partially activated, and non-activated patches on d-6. -Based on patch activity at time of fixed-time AI, the percentage of heifers with elevated concentrations of progesterone (> 1 ng/mL) on d -9 was different (P = 0.04) between heifers with activated, partially activated, and non-activated patches but the percentage of heifers with elevated concentrations of progesterone on d -6 did not differ (P = 0.59) between heifers with activated, partially activated, and non-activated patches at time of AI.

    USDA-ARS U.S. Meat Animal Research Center

    -Confirmed the association of a single nucleotide polymorphism in the KCND2 gene with age at puberty in beef heifers. -Validated a real-time RT-PCR assay for chemerin as a biomarker of adipose function in heifers.

    Future Work

    South Dakota State University

    -Further investigate the role of estradiol on the timing of embryonic loss. -Further investigate the control of estrus behavior (elevated estradiol) on pregnancy success.

    USDA-ARS U.S. Meat Animal Research Center

    -Extract DNA from buffy coats from the South Dakota Experiment Station and genotype to further validate the KCND2 marker in a group of heifers that have frequent blood samples and a more accurate puberty phenotype. -Granulosa cell cultures treated with chemerin to determine the influence of chemerin on steroid secretion. -Repeated adipose biopsies on cows being fluctuated in body condition score at the Minnesota Experiment Station to determine how the relative level of chemerin mRNA changes as BCS fluctuates.

    USDA-ARS U.S. Meat Animal Research Center

    -Initiating reproductive cycles before the start of breeding is the first hurdle that a replacement heifer must overcome. Results from this year provided further proof that a polymorphism in KCND2 that associated with age at puberty on the Bovine SNP50" could be a genetic marker for age at puberty. Age at puberty is a polygenic trait and it is unlikely that any single marker will explain all of the variation in age at puberty, but this provides a starting point for developing a panel of markers for age at puberty in beef heifers. -The development of biomarkers of fertility is as important as genetic markers, especially when one considers the high environmental influence on these traits. Immunoassays developed for use in humans are not cost effective and have potential problems in being validated for domestic species. Real time RT-PCR is used for diagnosing cancer types in humans. Developing biomarkers using real time RT-PCR and easily accessible tissues such as white blood cells and subcutaneous adipose could provide novel diagnostic tools for selecting replacement heifers.

    OBJECTIVE 2. To develop reliable, efficient, and economical breeding protocols for cattle

    Accomplishments/Outputs:

    University of Florida

    -Concluded calf removal was not able to improve pregnancy rates but did increase follicle growth rate prior to TAI. Subsequent calf performance was affected by 72 or 48 h calf removal. -Concluded pregnancy rates of heifers receiving perennial peanut hay were greater than the non-supplemented group, indicating perennial peanut hay may be a suitable alternative for development of replacement beef heifers. -Compared to traditional, single-time, 48-hour calf withdrawal, repeated 48-hour calf withdrawal resulted in greater cow pregnancy rate with a reduced period of postpartum anestrus. -Cow genotype influenced fetal size on d 62 and tended to influence concentrations of glycoprotein on d 35 and 62. Plasma glycoprotein concentration had a correlation with cow breed and plasma P4 concentrations, indicating maternal genotype may influence placental activity and early fetal development.

    Kansas State University

    -We concluded the modified 7-d CO-Synch + CIDR program in dairy heifers produced more P/AI in heifers inseminated at estrus than a standard 5-d CO-Synch + CIDR program, but when timed AI occurred at 72 h after PGF2a and CIDR insert removal, P/AI did not differ between programs. -We concluded that eCG treatment administered 3 d before insemination at the dose of 400 IU failed to increase follicle growth size and growth rate during 48 h after treatment and did not enhance pregnancy outcomes in lactating dairy cattle programmed for AI at first service. -We concluded that presynchronizing estrous cycles in lactating dairy cows with PG-3-G produced more P/AI than inseminating cows at estrus during cooler weather and was superior to Presynch-10 during summer. -In summary, more multiparous suckled beef cows in the PG-CO-Synch + CIDR treatment exhibited estrus and had greater pregnancy outcomes than primiparous suckled beef cows, but no overall treatment advantage was detected compared with the control (CO-Synch + CIDR). -In summary, presynchronization of estrous cycles with the PG-3-G treatment did not significantly increased pregnancy rates but earliest calving suckled beef cows (e 77 d since calving at AI) and those with BCS e 5.5 at onset of breeding program had greater pregnancy rates than later calving (< 77 d) and thinner (< 5.5) cows, respectively.

    University of Kentucky

    -Beginning October 2012, we will compare reproductive performance in cows bred using a standard TAI protocol versus cows bred based on activity monitored using the AfiAct activity monitoring system. -Currently determining how early pregnancy can be detected in milk using the IDEXX pregnancy detection assay

    University of Minnesota

    -The 5-d CO-Synch + CIDR (5d), PG 6-d CIDR (PG-CIDR), and 14-d CIDR-PG (CIDR-PG) protocols yield similar timed-AI pregnancy rates in virgin beef heifers. -Cow age affects the number of times a CIDR can be effectively used in the 5-d CO-Synch + CIDR protocol. In mature cows, the new and once used CIDR resulted in greater timed-AI pregnancy rates. In primiparous cows however, the opposite was observed where greatest pregnancy rates were achieved using a twice-used CIDR. -PGF administration 2 d before the onset of the 5-d program did not influence ovarian dynamics in anestrous females or synchronized pregnancy rate in postpartum cows. -Within the 5-d CO-Synch + CIDR protocol, initial results suggest that failure to ovulate to GnRH at CIDR insertion may not negatively impact pregnancy success and may benefit primiparous cows. However, before these conclusions are fully accepted, this study must be repeated to increase animal numbers and endocrine data must be evaluated.

    Mississippi State University

    -Provided evidence the synchronization process (administration of GnRH, PGF2±, and progesterone) does not impact concentrations of AMH. If measuring AMH becomes a reliable and economically feasible method to predict fertility, blood samples collected after synchronization should be as valuable as a blood sample collected without synchronization. This result will impact further research in this area. Furthermore, differences were detected between the two beef breeds and the two dairy breeds investigated. Additional research is necessary to elucidate the mechanisms of AMH production as well as to gain understanding in any potential breed differences.

    University of Missouri

    -Long-term CIDR-based protocols facilitate fixed-time artificial insemination in postpartum beef cows. -A range in interval from CIDR removal to PG may be feasible when using long-term CIDR-based protocols. -The 14-day CIDR-PG protocol was successful in facilitating fixed-time artificial insemination in Holstein heifers; however, pregnancy rates resulting from FTAI were higher for heifers that were inseminated with conventional semen compared to those that received sex-sorted semen. -Further studies are required to develop strategies for using sex-sorted semen when inseminating heifers at predetermined fixed times. -The Missouri Show-Me-Select Replacement Heifer Program provides the opportunity to tie improvements in reproductive management and improved genetics to economic endpoints.

    University of Nebraska

    -Developing heifers in a low input system (corn residue) resulted in acceptable AI and final pregnancy rates compared to a traditional drylot development system. -Calving earlier in the calving season impacted the performance of subsequent progeny, both steer and heifer calves. -Utilizing estrus synchronization systems, whether natural service or AI, increases the proportion of calves born earlier in the calving season. -Heifers synchronized utilizing the MGA-PG had similar reproductive performance compared with heifers synchronized utilizing the 14-d CIDR-PG protocol. -Cows synchronized with the CO-Synch + CIDR protocol had increased AI and overall pregnancy rates compared to cows synchronized utilizing the CO-Synch protocol, resulting in more CO-Synch + CIDR cows calving within the first 21 d of the calving season compared to CO-Synch cows.

    North Dakota State University

    -Experiment 1 provided insight into the effects of cyclic status of cattle bred via AI systems compared with those bred with natural service. The theory that products used for estrous synchronization can positively impact reproductive success of non-cyclic females was not supported by our data. Further research is warranted to validate the findings from the first year of this multi-year project. -Calves generated from respective breeding systems in Experiment 1 will serve as experimental units for studies that focus on post-weaning performance.

    South Dakota State University

    -FTAI pregnancy success did not differ between treatments (P = 0.13) and ranged from 53% to 63%. -Heifers that had reached puberty prior to the start of synchronization had greater fixed-time AI pregnancies compared to heifers that were prepubertal at protocol initiation (60.7% vs. 47.3%, respectively).At locations 2 and 3 where estrus activity at fixed-time AI was determined by tail paint scores there was an effect of tail paint score on fixed-time AI pregnancy success (P < 0.01). -Heifers that had a tail paint score of 1 (all tail paint removed; 64%) or 2 (tail paint partially removed; 58%) had greater fixed-time AI pregnancy rates compare to heifers that had a tail paint score of 3 (no tail paint removed; 43%). -Heifers that calved with their first calf during the first 21 d period of the calving season had increased (P < 0.01) longevity compared to heifers that calved in the second 21 d period, or later. Average longevity for USMARC heifers that calved in the 1st, 2nd, and later 21 d period was 8.2 ± 0.3, 7.6 ± 0.5, and 7.2 ± 0.1 yr, respectively. -Average longevity for South Dakota heifers that calved in the 1st or later 21 d period was 5.1 ± 0.1 and 3.9 ± 0.1 yr, respectively. -Calving period influenced (P d 0.03) weaning weight of the 1st, 2nd, 3rd, 4th, and 5th calf; but did not influence the weaning weight of the 6th (P = 0.24), 7th (P = 0.30), 8th (P = 0.30), or 9th (P = 0.37) calf (Figure 3). -Calving period influenced total kilograms weaned and mean weaning weight (P < 0.01), with heifers that calved during the 1st period having increased total kilograms weaned (898 ± 5.4 kg) and mean weaning weight (206 ± 0.3 kg) compared to heifers calving in the 2nd or later period, and heifers calving during the 2nd period having increased total kilograms weaned (768 ± 8.2 kg) and mean weaning weight (194 ± 0.5 kg) compared to heifers calving later (718 ± 16 kg and 174 ± 1.1 kg).

    USDA-ARS U.S. Meat Animal Research Center

    -Provided further evidence that maternal nutrient status in the third trimester can have positive influences on daughter performance. -Confirmed that limit feeding cows during the second and third trimester of pregnancy did not negatively impact reproductive performance in daughters.

    University of Wisconsin

    -Use of accelerometer systems for detection of estrus in lactating dairy cows can reduce the amount of synchronization to a point; however, some level of synchronization is required to deal with cows failing to be detected in estrus. -From an economic perspective, the three strategies compared for first AI using accelerometers with or without various levels of synchronization resulted in similar economic outcomes. -Use of transrectal ultrasonography to determine pregnancy status too soon after insemination is a major cause of pregnancy loss in lactating dairy cows due to a high rate of false positive outcomes. We recommend that bovine practitioners not conduct pregnancy diagnosis using transrectal ultrasonography until they can reliably detect the embryo and heartbeat, which is generally > 30 d post insemination.

    Future Work

    University of Florida

    -Further research on refinement on manipulation of estrous cycles to incorporate fixed-time AI in beef cattle to enhance fertility and reduce time and labor associated with fixed-time AI systems. -Current studies have been initiated to determine whether estrous cycles may be effectively synchronized in heifers to induce an ovulatory follicle that grows in the absence of exogenous progesterone.

    Kansas State University

    -We have completed a study of 69 lactating dairy cows to determine LH release in response to 2 presynchronization treatments (PG-3-G and Presynch-10; see figure under experiment #3 above) administered before an Ovsynch timed AI program. Cows were either given the second GnRH injection of Ovsynch at 56 or 72 h, with timed AI administered at 72 h in both cases. Blood samples were collected during 3 periods to assess LH concentrations: (1) around the period when GnRH was administered in the PG-3-G presynchronization treatment; (2) around the time of GnRH-1 of Ovsynch; and (3) around the time of GnRH-2 of Ovsynch. Ovaries also were scanned to determine follicle diameters and ovulation incidence. Blood serum concentrations of estradiol and progesterone also have been determined. Pregnancy per AI for presynchronization treatments and times of second GnRH injection are in the table below (treatment x time interaction; P = 0.085). -We are beginning a study to determine ovulation timing after increased activity (estrual) in lactating dairy cows associated with the Select Detect activity monitoring system (Dairymaster, Causeway, Co. Kerry, Ireland) to better understand when AI should be administered relative to onset of increased activity in addition to onset of standing events determined concurrently by HeatWatch. -We are conducting a study to determine whether placement of gender-biased semen ipsilateral or contralateral to the largest follicle determined 24 h after a 7-d CIDR + Lutalyse protocol will influence pregnancy outcome in dairy heifers. Semen is placed as far anterior as possible in the uterine horn either ipsilateral or contralateral to the largest follicle. Approximately 5 to 7 d after AI based on detected estrus, the side of ovulation (presence of new corpus luteum at site of previously identified largest follicle) will be verified to ensure that the semen was placed in the treatment-designated horn.

    University of Kentucky

    -Analyses of the completed experiments described above will determine the direction of future research.

    University of Minnesota

    -In collaboration with Bob Cushman at MARC, we plan on evaluating the follicular microenvironment, oocyte viability, and transcirptome changes in the oocyte, granulosa cells, and uterine endometrium in beef cows on varying planes of nutrition. -In collaboration with Bob Cushman at MARC, conduct repeated adipose biopsies on cows being fluctuated in body condition score to determine how chemerin mRNA levels change as BCS fluctuates. -In collaboration with The Ohio State University determine the impact of progesterone concentrations during follicular growth on oocyte quality as assessed via ultrasound-guided oocyte pickup and in vitro embryo production techniques. -In collaboration with South Dakota State University and University of Wyoming, assess the impact of post-AI nutrition on early embryonic development in beef heifers. -Determine if response to the initial GnRH in the 5-d CO-Synch + CIDR protocol impacts follicular dynamics and pregnancy success.

    Mississippi State University

    -A project evaluating dam nutritional stress during early gestation and the developmental programming effects to the offspring is in the first year and will continue. This project categorizes cows based on body condition score changes as well as metabolic changes measured by analysis of blood samples for leptin, glucose and NEFA. Calves born from dams in these nutritional categories will be assessed at birth and at one month of age for weight, growth, blood pressure, and blood flow in the carotid artery. Additional measurements such as age at puberty and first lactation milk production will also be assessed. This is a long-term project and year one has just been completed, calves will begin being born now. -Additional research will be conducted to improve reproductive efficiency in both dairy and beef cattle.

    University of Missouri

    -Further evaluation of methods to facilitate fixed-time artificial insemination in replacement beef heifers and postpartum beef cows. -Development of management strategies to facilitate use of sex-sorted semen in conjunction with fixed-time AI programs. -Identification, validation and characterization of the impact of recessive developmentally lethal alleles associated with reproductive failure in Angus cattle. -Development of a university/industry program that ties economic incentives back to adoption of reproductive technology and highly proven genetics.

    University of Nebraska

    -Additional research includes understanding how strategically supplementing around breeding time will impact reproduction. Heifer development research will continue to determine if heifers developed in low input systems are more efficient and/or better adapt to grazing crop residue. A project has been initiated controlling for fetal age and sire to determine amount of supplementation needed to prevent a negative fetal impact when cows graze dormant range. This study will also examine early or late weanings impact on supplementation needs.

    North Dakota State University

    -The long-tern project evaluating the impacts of incorporating artificial insemination into beef cattle breeding systems will follow calves into the post-weaning period. A backgrounding study will be conducted with steer calves to determine the intake, gain, and feed efficiency of calves from each system. In addition, a heifer development project will evaluate the intake, gain, feed efficiency, and proportion of females cyclic as the development phase progresses. -An effort to determine the sustainability of beef cattle breeding systems will be initiated with research performed on 10 commercial beef herds to determine the production, performance, and profit responses of breeding systems that incorporate artificial insemination compared with those that use only natural service. -A project has been initiated to collect real-time data at the time of pregnancy checking beef herds. Veterinary clinics will provide data and will benchmarking data and summary reports for their current clients, and data will be used to determine the impacts of several routine management practices on overall herd reproductive performance.

    South Dakota State University

    -To continue to Collaborate with USDA-MARC to try to determine selection criteria for heifer selection that will impact longevity in the herd.

    University of Wisconsin

    -We are currently working projects in four main areas: 1) the effect of mastitis on pregnancy loss and reproductive performance in lactating dairy cows; 2) the effect of rumen-protected choline on milk production and reproductive performance of lactating dairy cows; 3) use of rbFSH for superovulation in dairy cattle; and 4) development and optimization of hormonal protocols for synchronization of ovulation.

    Impact Statements:
    1. NC-1038 researchers found that by feeding heifers on high quality legumes (perennial peanut), heifers have similar weight gain and reproductive performance as when being fed on expensive grain-based supplements (with legume hay). This approach will save producers money that can be reinvested in their operation.
    2. By using hormone-based synchronized programming of ovulation for inseminations made at first service, scientists found that the costs of pregnancies were reduced by more than one-third, regardless of season of the year.
    3. NC-1038 researchers concluded that through reduced days open and genetic improvement (widespread use of artificial insemination) breeding efficiency in dairy cows will increase farm income by increasing milk production. This increase is valued at $100/cow.
    4. NC-1038 researchers found that many producers are interested in re-using CIDRs for estrous synchronization due to the cost associated with purchasing new CIDRs. NC-1038 scientists demonstrated that the 5-d CO-Synch + CIDR protocol, CIDRs can be used twice in mature cows without negatively impacting pregnancy rates.
    Last Modified: 20-Nov-2012
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