Annual/Termination Reports:

[10/21/2013] [10/31/2014] [10/28/2015] [10/07/2016] [10/11/2017]

Report Information

Participants

Bridges, Allen-University of Minnesota; Lamb,Cliff-University of Florida; Funston, Rick-University of Nebraska; Fricke, Paul-University of Wisconsin; Stevenson, Jeff-Kansas State University; Perry, George-South Dakota State University; Larson, Jamie-Mississippi State University; Dahlen, Carl-North Dakota State University; Mercadante, Vitor-University of Florida; Schook, Mellissa-University of Florida; Black, Dani-North Dakota State University; Kozicki, Luis-University of Florida; Turzillo, Adelle-USDA; Ravlin, Bill-The Ohio State University; Steckler, Teresa, University of Illinois; Kessler, Darrel-University of Illinois

Brief Summary of Minutes

Please see the attached document with the complete Annual Meeting Minutes.

Accomplishments

Overall across the experiment stations participating in NC-1201, 13 experiments/projects were conducted to meet Objective 1 and 23 experiments/projects were conducted to meet Objective 2. Many of these projects were collaborative efforts among stations and many have impacted not only future research in the field but are directly applicable to producers and other Extension efforts in the U.S. Individual experiment station accomplishments for each objective are listed below.<br /> <br /> <br /> Objective 1. To determine mechanisms that regulate reproductive processes impacting production efficiency in cattle.<br /> <br /> <br /> Mississippi State University:<br /> Gestational environment may impact growth and some hemodynamic parameters in young calves. Further research can lead to understanding the correlations and implications they may have on the dairy industry. Additional analyses of data are being conducted to potentially elucidate the mechanisms of these initial results. <br /> <br /> <br /> South Dakota State University:<br /> Follicle size had a positive relationship with peak concentrations of estradiol, but only among cows that exhibited standing estrus. <br /> <br /> <br /> Cows with greater circulating concentrations of estradiol during the preovulatory period had increased ability to produce estradiol and increased numbers of visible antral follicles. Thus, selection for both follicle numbers and estradiol concentrations during the preovulatory period may be a better indicator of fertility than either trait alone.<br /> <br /> <br /> Initiation of standing estrus prior to TAI resulted in improved embryo stage and quality and tended to improve accessory sperm numbers and percentage of live cells.<br /> <br /> <br /> University of Minnesota:<br /> Immediate alterations in early embryonic development are observed in heifers that fail to receive adequate nutritional inputs following insemination and these alterations are likely due to insufficient oviduct and uterine support of the developing embryo. Therefore, nutritional management following AI may influence subsequent pregnancy success.<br /> <br /> <br /> Administration of FSH increased the number of follicles aspirated, oocytes collected, proportion of grade 1 to 3 oocytes, and number of grade 1 to 3 oocytes per cow. Administration of FSH, however, did not affect the ability of the oocyte to cleave or develop into a blastocyst or affect the characteristics of subsequently developed blastocysts. Reducing progesterone concentrations during follicular development increased the number of follicles present at aspiration but did not impact quality of oocytes recovered or the ability of the oocytes recovered to cleave and develop into a blastocyst. Of interest, blastocysts generated from oocytes collected in cows with low progesterone concentrations were advanced in development had greater number of blastomeres following in vitro embryo production.<br /> <br /> <br /> In beef heifers, reducing progesterone concentrations within an ultrasound-guided ovum pick-up protocol that included FSH administration resulted in more oocytes collected and increased the number of grade 1 to 3 oocytes recovered per female.<br /> <br /> <br /> Amount of rumen undegradable protein present in the diet of beef females affects ovarian follicular development. Additional research is required to determine if these alterations to follicle dynamics due to RUP amount influence fertility.<br /> <br /> <br /> USDA-MARC:<br /> We demonstrated that the previous published work on the GRIA1 polymorphism as a functional mutation that influences antral follicle count is erroneous and that this genetic test should be used with care.<br /> <br /> <br /> We demonstrated that a previously published GnRHr polymorphism reported to impact reproductive performance in cattle may in fact do that, although there is very little evidence that this polymorphism is functional.<br /> <br /> <br /> We demonstrated that the myostatin F94L polymorphism, which has positive influences on carcass traits, may cause delayed puberty in beef heifers.<br /> <br /> <br /> University of Nebraska:<br /> Supplementation during winter grazing does not appear to impact cow rebreeding or progeny, however, supplementation does benefit heifer calves and primiparous heifer during the breeding season in a May calving herd.<br /> <br /> <br /> Low input heifer development systems result in acceptable AI and final pregnancy rates.<br /> <br /> <br /> Objective 2. Increase the efficiency and predictability of sustainable reproductive management programs for cattle.<br /> <br /> <br /> South Dakota State University:<br /> A decrease in bPAGs but not progesterone, in heifers that experienced late embryonic/fetal mortality, suggests that failure to maintain pregnancy may be initiated by the conceptus rather than due to inadequate luteal secretion of progesterone.<br /> <br /> <br /> There was no difference in the overall accuracy of the test (percent of time correctly identified; 92, 86, 89, and 92%, for estrous detection, Genex, UM, and Biotracking, respectively). Therefore, several options are available to determine pregnancy status in cattle.<br /> <br /> <br /> Prior grazing experience can impact grazing behavior and heifer performance when heifers are moved to spring forage.<br /> <br /> <br /> Kansas State University:<br /> In 3 experiments in lactating dairy cows whose ovulation was synchronized with a 5-d Ovsynch protocol, we concluded that the single 50-mg dose of PG administered on d 6 was equivalent to the control in which 25 mg of PG was administered on d 5 and d 6 based on actual luteal tissue regression and decreased concentrations of progesterone to verify luteolysis.<br /> <br /> <br /> We concluded that fewer Presynch10 (two 25-mg injections of PGF2± (PG-1 and PG-2) 14 d apart (Presynch) than PG3G (one 25-mg injection of PG 3 d before 100 ¼g GnRH (G-1), with the PG injection administered at the same time as PG-2 cows) subsequently enrolled in a TAI protocol 10 d after PG-2 (Ovsynch; injection of GnRH 7 d before [G-2] and 56 or 72 h after [G-3] PG-3 with AI at 72 h after PG-3) ovulated and had LH surges at G-1. This observation is consistent with our earlier report (J. Dairy Sci. 95:1831-1844) in which PG3G cows had increased ovulation rates at G-1 and greater (P = 0.069) progesterone at G-2 (4.1 vs. 2.7 ± 0.5 ng/mL) than Pre10 cows.<br /> <br /> <br /> We concluded that effective use of the CIDR insert to increase P/AI is progesterone-dependent for cows initiating RES on d 34. Although d 31 PG3G increased luteolysis and greater ovulation rates before RES, no increase in P/AI compared with RES started on d 41 with or without a CIDR insert.<br /> <br /> <br /> A close relationship exists between onset of standing-to-be-mounted and increased physical activity as measured by neck-mounted accelerometers. Strong correlations were detected between estrual and ovulation traits as defined by standing-to-be-mounted and the activity monitors. Near perfect correlations between HW- and SD-defined onset and end of estrus were detected.<br /> <br /> <br /> Preliminary results indicated little if any effect of semen placement on pregnancy outcomes in heifers when inseminated with gender-biased semen.<br /> <br /> <br /> Mid-range progesterone concentrations (1 to 4 ng/mL) measured 10 d before the onset of the CO-Synch + CIDR protocol in suckled beef cattle tended to predict subseqeuent pregnancy per timed AI. Concentrations of progesterone at CIDR insert were not predictive of subsequent pregnancy outcome. A 3-way interaction of parity, days postpartum, and BCS indicated that older, more conditioned, and further postpartum cows were more likely to conceive in a CO-Synch + CIDR timed AI protocol than thinner contemporaries and those that inseminated earlier postpartum. Cows at greatest risk for not conceiving to AI were primiparous, thin, and earlier postpartum cows.<br /> <br /> <br /> University of Minnesota:<br /> Within the 5-day CO-Synch + CIDR protocol in beef heifers, the necessity to administer GnRH at CIDR insertion is questionable. Pregnancy rates were not affected when GnRH administration was withheld. Additional research, in larger numbers of heifers, is required to confirm this finding.<br /> <br /> <br /> University of Kentucky:<br /> Preliminary data indicts that cows with the AFI system had an additional 15 days to first service compared to cows on the OVSYNCH treatment.<br /> <br /> <br /> Milk-based PAG ELISA results were accurate in predicting pregnancy in 7 of 7 pregnant cows.<br /> <br /> <br /> University of Wisconsin-Madison:<br /> Presynchronization with a modified Ovsynch protocol increased P/AI by increasing synchrony to the Ovsynch56 protocol particularly during heat stress compared to presynchronization with a single injection of GnRH. <br /> <br /> <br /> A single dose of long-acting rbFSH (either 100 µg of A-rbFSH or 50 µg of B-rbFSH but not 50 µg of A-rbFSH) induced superovulation and produced the same quantity of good-quality embryos compared to pituitary-derived FSH. <br /> <br /> <br /> Supplementing RPC during the transition period did not affect milk components but increased milk yield for older cows during and beyond the postfresh supplementation period.<br /> <br /> <br /> USDA-MARC:<br /> In collaboration with two other Experiment Stations (SDSU and UNL), we published further supportive evidence that calving early as a heifer has positive influences on reproductive longevity and calf weaning weights through six parturitions.<br /> <br /> <br /> North Dakota State University:<br /> 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. <br /> <br /> <br /> Calves generated from respective breeding systems in Experiment 1 will serve as experimental units for studies that focus on post-weaning performance.<br /> <br /> <br /> University of Nebraska:<br /> Calving distribution impacts steer and heifer progeny.<br /> <br /> <br /> Synchronization systems improve early calving frequency.<br /> <br /> <br /> University of Missouri:<br /> Results from Experiment 1 indicate that greater FTAI pregnancy rates to sex-sorted semen may be achieved by delaying insemination of non-estrous cows. Use of an estrus detection aid may be useful for producers in classifying females as having expressed estrus or as having failed to express estrus prior to FTAI. Females classified as having expressed estrus could be inseminated at the standard time, and females classified as not having expressed estrus could receive GnRH followed by insemination 20 h later. This strategy offers producers the opportunity to achieve acceptable AI pregnancy rates to sex-sorted semen without the need to visually detect estrus and inseminate over multiple days as in an estrus detection system. <br /> <br /> <br /> <br /> Results summarized from the Missouri Show-Me-Select Replacement Heifer Program indicate that evaluation of reproductive status of heifers prior to the first breeding season is useful in determining success of the development period and in determining which protocol to use to synchronize estrus prior to FTAI. Results from these field data suggest that the 14-d CIDR-PG protocol provides an advantage in synchronizing estrus and ovulation prior to FTAI, primarily among non-cycling heifers.<br /> <br /> <br /> University of Florida:<br /> We determined that administration of PGF2± at CIDR insertion during the CO-Synch + CIDR estrus synchronization protocol failed to enhance pregnancy rates in cows and heifers. <br /> <br /> <br /> Based on actual experimental data a smart phone application was developed to assist beef cattle producers and industry professionals as a decision aid when deciding whether to utilize artificial insemination or purchase herd sires. The application allows user to utilize their own costs and anticipated outcomes. <br /> <br />

Publications

Please see the attached document.

Impact Statements

1. Development of a smart phone application utilizing data from a previous study (Rodgers et al., 2012) indicates that for every cow exposed to a timed artificial insemination (TAI) protocol a cattle producer will gain an additional $49 per cow after weaning. Today approximately 2 million cows are exposed to TAI, resulting in $98 million increase in value of weaned calf value per cow. The potential impact if all 30 million cows in the United States were exposed to TAI may result in an additional $1.5 billion dollars in calf value per cow compared to cows not exposed to TAI.
2. Utilizing activity monitors to predict estrus and ovulation is as effective as using rump-mounted radiotelemetric sensors that identify standing estrus at similar input costs. Further, labor inputs are significantly less in maintaining the rump-mounted sensors compared with neck-mounted accelerometers. Onset of estrus or onset of increased activity is accurately defined by both systems and ovulation is highly predictable based on time from onset or end of estrus or peak activity. Both systems can reduce inter-insemination intervals and increase pregnancy rates (shorted intervals from calving to pregnancy) compared with timed AI programs without detection of estrus.
3. NC-1201 researchers have established low input heifer development systems that have resulted in a $100/head savings per pregnant heifer over most conventional heifer development systems.
4. NC-1201 scientists established a system to monitor real-time pregnancy rates in the Upper Great Plains and enabled veterinarians to provide individual consultation on almost 500 beef cattle operations. This system capitalized on data generated by sentinel veterinary clinics and allowed researchers to evaluate the impact of best management practices on herd level reproductive performance.

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Report Information

Participants

Brief Summary of Minutes

See attached Copy of Minutes file for NC1201's annual report. External funding leveraged by NC1201 presented upon request.

Accomplishments

Publications

Impact Statements

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Report Information

Participants

Abel, Jillian – University of Missouri;
Carvalho, Paulo – University of Wisconsin;
Cooke, Reinaldo – Oregon State University;
Cushman, Robert – US-MARC;
Fricke, Paul – University of Wisconsin;
Garverick, Allen – University of Missouri;
Hamernik, Deb – University of Nebraska
(Administrative Adviser);
Hill, Scott – Kansas State University;
Lamb, Cliff – University of Florida;
Larson, Jamie – Mississippi State University;
Murphy, Cliff – University of Missouri;
Muth-Spurlock, Ashleigh – Mississippi State University;
Patterson, David – University of Missouri;
Rhoads, Michelle – Virginia Tech;
Soares, Emerson – US- MARC;
Steckler, Teresa, University of Illinois;
Stevenson, Jeffrey – Kansas State University;
Thomas, Jordan – University of Missouri;
Turzillo, Adelle – USDA-NIFA (by telephone)

Brief Summary of Minutes

Meeting called to order at 7:50 a.m. on September 9th by Dr. Teresa Steckler, Chair

Introductions of attendees

Welcome by Dr. Tom McFadden, Chair, Division of Animal Sciences

Announcements
2015 JAM Physiology and Endocrinology program. Two symposia are being planned: (1) Epigenetics of Growth organized by Kim Vonnahme, NDSU and (2) History and Contributions of the Dairy Cattle Reproduction Council (DCRC) and Applied Reproductive Strategies in Beef Cattle (ARSBC) organized by Cliff Lamb

Station reports
Florida by Dr. Cliff Lamb
US-MARC by Dr. Robert Cushman and Emerson Soares
Wisconsin by Paulo Carvahlo and Dr. Paul Fricke
Mississippi by Ashleigh Muth-Spurlock and Dr. Jamie Larson
Missouri by Jordan Thomas and Dr. David Patterson

Adjourned for catered lunch at 12:25 p.m.

Meeting resumed at 1:00 p.m.

Reports by NIFA and Administrative Advisers (Adelle Turzillo and Deb Hamernik)

?
Station Reports resumed
Kansas by Dr. Jeffrey Stevenson
Illinois by Dr. Teresa Steckler
Virginia by Dr. Michelle Rhoads

Adjourned to attend overview presentations by selected faculty from the University of Missouri (Drs. Randy Prather, Michael Smith, Tom Spencer, Jeremy Taylor, and Jared Decker)

Meeting adjourned for the day at 5:20 p.m.

Meeting called to order at 8:00 a.m. on September 10th by Dr. Teresa Steckler, Chair

Station Reports
Virginia by Dr. Michelle Rhoads (continued from the previous day)
Oregon by Dr. Reinaldo Cooke

Business Meeting

Reinaldo Cooke will serve as Secretary for the 2016 annual meeting
Jeffrey Stevenson will serve as Chair for the 2016 annual meeting

Two alternative locations and dates were discussed for the 2016 annual meeting:
1. Week of August 22, 2016 either preceding or following the ARSBC meeting in Des Moines, IA (Host: George Perry)
2. September 7-8 in Bloomington, IL at the Farm Bureau complex (Host: Teresa Steckler)
Dr. Patterson will follow-up on the dates for the ARSBC meeting and inform Dr. Stevenson. Dr. Stevenson will communicate with the committee and then set the date and location by vote.

Responsible parties for writing the new project:
Dr. Cushman will take lead for the Epigenetics-Fetal Programing section
Dr. Fricke will take lead for the dairy section
Drs. Lamb, Patterson, and Steckler will take lead for the beef section
Each station representative was tasked to ponder various ideas and provide a paragraph summary of potential station contributions to the new project.

Rewrite Schedule per Dr. Hamernik:
September 15, 2016 Intent to renew submitted to NIMS
Statement of Issues (Justification and Rationale)
October 15, 2016 Objectives
November 15, 2016 Appendix E filed for all station representatives
December 15, 2016 Project write-up is due

Meeting adjourned at 11:55 a.m.

Accomplishments

Objective 1. To determine mechanisms that regulate reproductive processes impacting production efficiency in cattle.<br /> Role of molecular pathways in regulating reproductive function (MN, SD, USDA-MARC)<br /> Impact of maternal environment on progeny (FL, MN, MS, ND, NE, ND, MN, USDA-MARC, FL)<br /> To examine the use of new technologies to assist with enhancing reproductive performance (KY, WI)<br /> <br /> North Dakota<br /> Nutrient transporters in bovine utero-placental tissues on days 16 to 50 of gestation were studied. The hypothesis was that transporters for glucose and amino acids in utero-placental tissues would be differentially expressed across days of early pregnancy. To test this hypothesis, crossbred Angus heifers (n = 46), were synchronized, bred via AI and then ovariohysterectomized on d 16, 22, 28, 34, 40, or 50 of gestation (n = 5 to 9/d), or were not bred and ovariohysterectomized on d 16 of the synchronized estrous cycle (n = 7) to serve as nonpregnant (NP) controls. These results support our hypothesis that there is an effect of day on the expression of glucose and amino acid transporter mRNAs in utero-placental tissues of heifers during early pregnancy.<br /> <br /> South Dakota<br /> Estradiol has been reported to play a critical role in pregnancy establishment and embryonic survival. Our objective was to focus on the role of preovulatory estradiol in embryo survival from fertilization to maternal recognition of pregnancy. Estrus was synchronized in beef cows (n = 29) with the CO-Synch protocol and inseminated (d 0). In summary, there were no differences between cows that did or did not express estrus in ISG expression, or in protein or glucose concentration of uterine flushes. Therefore, the increased embryo survival to d 30 of gestation among cows that express estrus is not associated with embryo survival until maternal recognition.<br /> <br /> Among cattle the LH surge that causes ovulation occurs shortly after the onset of a spontaneous estrus. In addition an injection of 100 ?g of GnRH can induce an LH surge capable of inducing ovulation. We hypothesized that different preovulatory estradiol profiles would result in different ovulatory LH surges, and that an injection of GnRH (100 ?g) would induce a secondary LH surge among cows that exhibited standing estrus prior to the GnRH injection. In order to establish the importance of estradiol on initiating an LH surge, ovariectomized multiparous cows (n=26) received estradiol cypionate (ECP), estradiol benzoate (EB) or no treatment (CON) to mimic a preovulatory period. There was an effect of treatment, time, and a treatment by time interaction (P < 0.01) on circulating concentrations of LH, with ECP treated cows having increased concentrations of LH at hour -16, -12, -8, and -4 compared to EB and CON. However, EB had greater concentrations of LH than ECP at 30, 60, 90, 120, and 150 min after GnRH and CON having greater concentrations of LH at 30 and 60 min after GnRH compared to ECP. In summary, exogenous estradiol influenced timing and peak concentrations of an LH surge.<br /> <br /> US-MARC-Nebraska<br /> Presentation concerning the marker assisted population?markers for growth and carcass traits, including the MSTN (myostatin allele). Presentation of information concerning their stair-step nutrition approach to study puberty and ovarian reserves (increase in primordial follicles, but no changes in primary or secondary follicles). During refeeding period, an increase in gene expression occurred suggesting a genomically directed change in ovarian function by feeding. Studies concerning the effects of body condition score and oocyte quality are underway in beef heifers.<br /> <br /> Aspiration of bovine follicles 12–36 hours after induced corpus luteum lysis serendipitously identified two populations of cows, one with High androstenedione (A4; > 40 ng/ml; mean = 102) and another with Low A4 (<20 ng/ml; mean = 9) in follicular fluid. We hypothesized that the steroid excess in follicular fluid of dominant follicles in High A4 cows would result in reduced fertility through altered follicle development and oocyte maternal RNA abundance. These data suggest that the dominant follicle environment of High A4 cows including reduced estrogen conversion and androgen excess contributes to infertility in part through altered follicular and oocyte development.<br /> Mississippi<br /> Research is underway to examine factors associated with each dominant follicle of the estrous cycle in the cow and how these factors influence oocyte fertility. Dominant follicles ipsilateral to the CL grow slower than those contralateral to the CL. Studies examining ovarian function in cows fed endophyte-infected seed (fescue toxicosis) and control MaxQ nontoxic fescue seed. Blood perfusion in the ovary measured by doppler is not affected by fescue treatments.<br /> <br /> Kansas<br /> An experiment was conducted with the objective to determine the effects of estradiol, progesterone, presence of a corpus luteum (CL), and (or) size of a dominant follicle on the characteristics and patterns of GnRH-induced LH release and subsequent ovulation during a timed artificial insemination (TAI) program. In 70 lactating dairy cows, a total of 163 blood collection periods resulting in a GnRH-induced LH release was analyzed. Measures of LH included: time to LH peak concentration during the 6-h blood collection period, the two largest concentrations of LH, mean, and variance of the 6 LH concentrations, baseline LH mean and variance, and area under each LH curve. Individual and combination effects of CL presence and a dominant follicle less than or >13.5 mm, in addition to individual and combination effects of progesterone: low (<0.45 ng/mL; n = 83), medium (0.53 to 2.41 ng/mL; n =25), and high (2.66 to 10.7 ng/mL; n =55), and estradiol: low (<4.0 pg/mL; n = 89) and high (>4.0 pg/mL; n = 74) were independent variables in models to determine their influence on characteristics of LH and ovulation. Measures of GnRH-induced LH concentration were inhibited at greater concentrations of progesterone and in the presence of a CL. In contrast, GnRH-induced LH concentrations were increased when estradiol was >4.0 pg/mL, but relatively unaffected by the size of dominant follicle. Furthermore, resulting incidences of ovulation were decreased at greater progesterone concentrations and presence of a CL, and increased at greater estradiol concentrations and presence of a follicle >13.5 mm. Peak GnRH-induced LH concentration was greater in cows with progesterone <0.45 ng/mL and ovulation incidence was increased from 70.4 to 85.1%. In cows with or without a CL, the presence of a follicle >13.5 mm did not increase mean LH concentration or incidence of ovulation. We conclude that presence of a CL and elevated progesterone concentration at the time of GnRH treatment of cows in TAI programs is inhibitory to subsequent LH responses and ovulation, but in the face of larger concentrations of estradiol and increased LH concentrations, more cows ovulated, and likely influences subsequent TAI pregnancy outcomes.<br /> <br /> Virginia<br /> Heat stress at the time of conception affects the subsequent milk production of primiparous Holstein cows; however, it is unknown whether these effects are maintained across multiple lactations. Therefore, the objective of the current study was to examine the relationship between periconceptional heat stress and measurements of milk production and composition in cows retained within a herd for multiple lactations. Milk production was significantly affected by periconceptional heat stress. When a significant difference or tendency for a difference was detected between the HSC and TNC cows, the TNC produced more milk in all but one comparison. The advantage in milk production for the TNC cows over the HSC cows ranged from 82 ± 42 to 399 ± 61 kg per lactation. Alterations in fat and protein percentage were variable and most often detected in first lactations (first > second or third). Overall, the most striking result of this study is the consistency of the relationship between HSC and milk production. The nature of this relationship suggests that heat stress at or around the time of conception impairs cow milk yield throughout her lifetime.<br /> <br /> Pre-pubertal exposure of the developing ovaries and reproductive tract (RT) to estrogen or xenoestrogens can have acute and long-term consequences that compromise the reproductive performance of cattle. This research examined effects of the selective estrogen receptor modulator tamoxifen (TAM) on gene and protein expression in pre-pubertal ovaries and RT with particular focus on signaling pathways that affect morphology. Results indicate that reproductive development in prepubertal Holstein heifer calves is TAM-sensitive, and that bovine RT and ovarian development are supported, in part, by ER-dependent mechanisms during the period studied here. Potential long-term consequences of such developmental disruption remain to be defined.<br /> <br /> Early weaning is a management strategy that has long-term benefits for the growth and development of cattle. Most research investigating the effects of early weaning has focused on terminal growth and carcass characteristics rather than traits that are important for replacement breeding heifers. In an effort to better understand the consequences of early weaning for heifers retained in the breeding herd, the following experiment was designed to investigate the impact on reproductive performance and metabolic function. Taken together, these results demonstrate that a lesser insulin response was necessary to properly clear the glucose in the EW heifers, and are indicative of greater insulin sensitivity in the EW heifers.<br /> <br /> Nebraska<br /> Effect of post-weaning heifer development on pregnancy rates and subsequent feed efficiency as a pregnant first calf heifer. To determine the impact of heifer development system on pregnancy rates and feed efficiency as a pregnant first calf heifer a 3 yr study was conducted. In Yr 1, weaned heifers either grazed corn residue (CR) or were fed in a drylot (DLHI). In Yr 2 and 3 heifers either grazed CR, upland range (RANGE), or were fed diets differing in energy, high (DLHI) or low (DLLO), in a drylot setting. Percent of mature BW prior to the breeding season was similar among treatments except DLHI which was significantly greater (P = 0.04) at 66.6% compared to 60.0, 61.0, and 61.7% for RANGE, CR, and DLLO treatments, respectively. Pregnancy rates to AI were similar (P = 0.62) among treatments (58.6, 66.3, 59.9, 52.6 ± 9.7%; RANGE, CR, DLHI, DLLO). A subset of AI-pregnant heifers from each development treatment were placed in a Calan gate system; they were allowed a 20 d acclimation and training period before beginning the 90 d ad libitum hay treatment period on approximately gestational d 170. Offerings were recorded daily and orts collected weekly. Initial BW was not different (P = 0.62) among treatments (458, 468, 473, 464 ± 9 kg; RANGE, CR, DLHI, DLLO). Body weight at the end of the treatment period was also not different ([P = 0.55] 485, 497, 503, 491 ± 17 kg; RANGE, CR, DLHI, DLLO). Intake did not differ among treatments, either as DMI ([P = 0.59] 9.2, 9.4, 9.5, 9.4 ± 0.7 kg; RANGE, CR, DLHI, DLLO) or as a percentage of BW ([P = 0.98] 1.96, 1.95, 1.95, 1.96 ± 0.15%; RANGE, CR, DLHI, DLLO). There was no difference (P = 0.61) in ADG (0.28, 0.33, 0.32, 0.28 ± 0.17; RANGE, CR, DLHI, DLLO) or residual feed intake (P = 0.41) (-0.095, -0.096, 0.144, 0.113 ± 0.156; RANGE, CR, DLHI, DLLO) among treatments. Although there was no difference (P = 0.41) in the 3-mo-development cost among treatments ($166.06, 141.66, 160.63, 171.80 ± 12.52; RANGE, CR, DLHI, DLLO), there was a $30.14 numerical difference between the most expensive treatment, DLHI, and the least costly treatment, CR. Post-weaning heifer development system did not impact heifer pregnancy rate or feed conversion as pregnant first calf heifers. <br /> <br /> Effect of MGA vs CIDR estrus synchronization on estrus response and pregnancy rates in 311 d old beef heifers. A study compared the effect of melengestrol acetate (MGA)-PG and 14-day controlled internal drug release (CIDR)-PG estrus synchronization protocols on estrus response and pregnancy rates of 311 d old Angus-based, crossbred heifers (n = 153). Fall-born heifers, at 10 mo of age, were assigned randomly to 1 of 2 estrus synchronization protocols in the spring (2 replications/treatment). Heifers in the MGA protocol received MGA for 14 d fed through the diet beginning on d 0 of the synchronization treatment period. Heifers in the CIDR treatment received the same diet as MGA heifers and were implanted with a CIDR (Eazi-breed CIDR) on d 2 of the treatment period and removed on d 16. Following estrus synchronization, heifers from both treatments were combined and received a single PG (Lutalyse) injection on d 32. All data was analyzed with the GLIMMIX procedure of SAS (SAS Inst. Inc., Cary, NC). Heifers with activated heat detection aids (Estrotect) were AI 12 h following observation. Group BW was measured at weaning (198 kg) and prior to breeding (273 kg). Pre-breeding BW was 50.1% of predicted mature BW. Heifer age at breeding was not different (P = 0.12) between MGA and CIDR treatment groups. Percentage of heifers demonstrating signs of estrus was similar (P = 0.42) between synchronization treatment groups (CIDR vs MGA, 71.5 vs 77.4 ± 1.0%). Heifers not expressing estrus were not given an opportunity to become pregnant and removed from the herd. Pregnancy rates to AI of heifers expressing estrus (n = 115) were similar (P = 0.27) between CIDR and MGA synchronization treatment (46.3 vs 36.1 ± 6.8%). Bulls were placed with heifers at a 1:25 ratio 10 d following AI. Final pregnancy rate was also similar (P = 0.96) between CIDR and MGA treatment groups (51.0 vs 51.5 ± 7.4%). Heifer BW at pregnancy diagnosis was not different (P = 0.45) between CIDR and MGA treatment groups (325 vs 321 ± 3.4 kg). The numerical 10% decrease in AI pregnancy rate in MGA compared with CIDR synchronization is not significant but is of interest. Approximately half of these 311 d old heifers exposed to AI and bulls became pregnant.<br /> <br /> Economic aspects of rebreeding non-pregnant cows. A study was conducted to evaluate the economic aspects of retaining ownership and rebreeding open spring-calving cows to be sold as pregnant fall-calving cows. Composite Red Angus × Simmental females diagnosed as non-pregnant after regular spring breeding season were utilized over a 2 yr period (Yr 1, n = 61; Yr 2, n = 72). Hay and supplement were fed from November to February. Cows diagnosed as non-pregnant after a second breeding season were sold in March. Pregnant cows grazed Sandhills meadow pastures until April, when they were sold. Cows were synchronized with a 7-d controlled internal drug release (CIDR)-PG protocol prior to a 60 d natural service breeding season beginning in November, utilizing a 1:25 bull to cow ratio. Pregnancy diagnosis was determined by ultrasound 30 d after bull removal. A partial budget analysis was performed for Yr 1 to compare the economics of selling non-pregnant cows immediately after pregnancy diagnosis or retaining ownership and rebreeding them to sell as pregnant cows in more favorable market prices. Total cost was calculated by adding the purchase price (cull cow value at first pregnancy diagnosis), feeding costs, meadow grazing and management cost, breeding cost, and 6% annual interest rate on the purchase price. The net cost of 1 pregnant cow was calculated as the difference between total cost and cull value, divided by the number of pregnant cows. The overall rebreeding pregnancy rate was 90.2% for Yr 1 and 81.9% for Yr 2, the percentage of the pregnant cows that conceived in the first 21 d of the breeding season was 89.1% for Yr 1 and 79.7% for Yr 2. The total cost/female was $1,186.38. Subtracting the cull value of the open cows sold in March, the net cost of one pregnant cow was $1,185.08. The pregnant cows were sold for $1,638.00, resulting in a $452.92 net gain/pregnant cow. While conventional wisdom has held open cows should be sold after pregnancy detection, we conclude rebreeding a non-pregnant cow to be sold at higher market prices may be an economic alternative.<br /> <br /> Objective 2. To increase the efficiency and predictability of sustainable reproductive management programs for cattle.<br /> Pre- and post-insemination strategies to optimize reproductive efficiency (FL, KS, KY, MN, MO, MS, ND, NE, SD, USDA-MARC, WI)<br /> Reproductive management programs to facilitate artificial insemination in cattle (FL, KS, KY, MN, MO, MS, ND, NE, SD, USDA-MARC, WI)<br /> <br /> North Dakota<br /> Strategies of synchronizing estrus for natural service breeding in suckled beef cows was studied (n = 1,520) in commercial operations in Uruguay and managed in grazing pastures. Cows were stratified by body condition score (mean of 3.94), then randomly assigned to one of four treatments in a 2×2 Latin square design with factors of PGF (yes or no) and CIDR (yes or no) to receive: (1) no treatment prior to initiation of the breeding season (Control, n = 389); (2) 25 mg prostaglandin F2? (PGF) i.m. on day of bull turnout (d 0, PGF, n = 383); (3) a controlled internal drug releasing insert (CIDR) 7 days prior to bull turnout (d -7) with removal on d 0 (CIDR, n = 375); or (4) a CIDR on d -7 followed on d 0 with CIDR removal and 25 mg PGF (CIDR-PG, n = 373). Mature bulls that passed a breeding soundness examination were placed in pastures with cows a rate of 25 cows per bull for the duration of the breeding season. Season ending pregnancy status was determined via palpation per rectum or transrectal ultrasonography. No interaction was present (P = 0.41) among PGF and CIDR factors for final pregnancy rate. Final pregnancy rates were greater (P < 0.01), however, for cows administered PGF (76.3%) compared with those not receiving PGF (69.4%). Administration of a CIDR had no impact (P = 0.21) on final pregnancy rates (71.3% and 74.6% for cows receiving a CIDR and cows not receiving a CIDR, respectively). At the time of calving (September-December 2015) the date will be recorded and used to evaluate calving distribution for each treatment. In addition, weight of each resultant calf will be recorded at the time of weaning.<br /> <br /> A Bull Test project was initiated at the request of veterinarians participating in the NDSU PregCard project. The goal of the project was to summarize incidence and reasons for failure of reproductive soundness examinations in yearling and mature bulls. Results: (1) BullTest cards were an effective way to collect data; (2) more yearling bulls failed tests because of semen morphology issues compared with mature bulls; (3) more mature bulls failed tests because of penile defects compared with yearling bulls; (4) failure rate was greater for yearling and mature bulls that were retested compared with bulls tested for the first time; (5) no statistical differences were observed in failure rates between tests that included a full BSE and tests that just evaluated semen; (6) no statistical differences were observed between herd tests and tests for bull sales; and (7) more data are needed to confirm results and to determine whether data tendencies are truly significant.<br /> <br /> South Dakota<br /> Cryopreservation allows for long-term storage of semen. However, cryopreservation and thawing imposes stress on spermatozoa, and prematurely initiates the process of capacitation; possibly decreasing sperm lifespan. Liquid semen is not exposed to these stressors, leading to a potential longer lifespan in the female reproductive tract and thus increasing the window for successful insemination. The objective of this study was to compare fertility of liquid and frozen semen when varying the interval from CIDR removal to insemination using the 7-day CO-Synch + CIDR protocol. In summary, there was no difference in pregnancy success between liquid and frozen semen. However, cows that exhibited estrus and inseminated at 60 h after CIDR removal had greater pregnancy success compared to cows that did not exhibit estrus.<br /> <br /> Virginia<br /> This experiment examined how follicular fluid affects the in vitro maturation of cumulus oocyte complexes. The magnitude of cumulus cell expansion during the maturation phase affects the ability of bovine oocytes to undergo fertilization and develop to the blastocyst stage in vitro. The objective of this study was to determine how inclusion of follicular fluid in maturation media would affect the trajectory and final rate of cumulus cell expansion. Preliminary studies indicate that when COC are subjected to in vitro fertilization (n=37-160 per treatment per replicate, 10 replicates), inclusion of follicle fluid at a rate of 75% does not increase cleavage rates nor improve blastocyst rates. Thus, even though maturation of COC in 75% follicle fluid resulted in the greatest amount of cumulus cell expansion during in vitro maturation it did not improve the apparent developmental potential of oocytes following fertilization.<br /> ?<br /> US-MARC<br /> The use of genetic markers to aid in selection decisions to improve carcass and growth characteristics is of great interest to the beef industry. However, it is important to examine potential antagonistic interactions with fertility in cows before widespread application of marker-assisted selection. The objective of the current experiment was to examine the influence of 2 commercially available markers currently in use for improving carcass traits, the myostatin (MSTN) F94L and ?-calpain (CAPN1) 316 and 4751 polymorphisms, on heifer development and reproductive performance. From these results, we concluded that the MSTN F94L and CAPN1 polymorphisms can be used to improve carcass traits without compromising fertility in beef heifers. The influence of these markers on cow performance and herd life remains to be determined. While the delay in puberty associated with the MSTN F94L polymorphism did not negatively impact reproductive performance in heifers, caution should be used when combining this marker with other markers for growth or carcass traits until the potential interactions are more clearly understood<br /> <br /> Florida<br /> Dr. Lamb reviewed the progress made at the North Florida Research and Extension Center in Marianna in reducing the breeding season of their station cow herd by introducing AI in 2006. Duration of the breeding season was reduced in a stair-step fashion from 120 days with all natural service to 72 days. A stringent culling strategy was followed (culling all cows not conceiving in breeding season; retaining only replacement heifers that conceived during the first 25 days of the breeding season). Results included reducing the mean calving day from 79.2 to 38.7 days and increasing the value of weaned calves from $87 in 2008 to $169 in 2013 (increased weaning weights resulting from more calves born earlier in successive breeding seasons). We conclude that exposing beef females to TAI and reducing the BS length for six years altered calving distribution, increased breeding season pregnancy rates, and increased calf value.<br /> <br /> A total of 190 multiparous suckled beef cows composed of Angus, Brangus, and Braford were enrolled in the experiment. All cows were subjected to the 7-d CO-Synch + CIDR estrus synchronization protocol. In brief, cows received a 100-?g injection of GnRH (2 mL Factrel; Zoetis Animal Health) at CIDR (1.38 g P4; Zoetis Animal Health) insertion [d -10] with a 25-mg injection of PGF (5 mL Lutalyse; Zoetis Animal Health) at CIDR removal [d -3], followed by an injection of 100-?g GnRH and TAI [d 0] at 66 h after CIDR removal. Cows were blocked by breed and stratified by DPP and BCS, and randomly assigned to receive one of the following treatments: 1) two injections of placebo (1 mL of 0.9% saline), one at TAI and a second injection 14 d after TAI (CTRL, n = 53); 2) two injections of 325 mg bST (Posilac, Elanco Animal Health, Greenville, IN, USA), one at TAI and a second injection 14 d after TAI (2bST, n = 40); 3) one injection of 325 mg bST at TAI and a placebo injection 14 d after TAI (TAIbST, n = 48); and 4) a placebo injection at TAI and one injection of 325 mg bST 14 d later (d14bST n = 49). We conclude that administration of 325 mg bST during the time of TAI to suckled beef cows enhanced concentrations of IGF-1, but failed to improve pregnancy rates, fetal size, PSPB concentrations, and had no effect on calf birth weight.<br /> <br /> ?<br /> Wisconsin<br /> Presentation of reproductive program used at the UW Dairy to push their herd 21-day pregnancy rates to34%. All cows are inseminated at first service using Double Ovsynch. Once inseminated, a pre-GnRH injection is administered 25 days later and pregnancy diagnosis at 32 days. Open cows with a corpus luteum received PGF2? (PG) at open check and a second dose 34 hours later. At 56 hours after the first PG injection GnRH is administered and occurs 16 hours later. Cows with no CL receive GnRH and a CIDR, PG 7 days later, GnRH in 56 hours and AI 16 hours after GnRH. Milk production (305-day) is in excess of 30,000 lbs.<br /> <br /> Studies are underway examining the incorporation of a second PG injection in the Ovsynch program to improve the risk of luteolysis in both 5 and 7day programs. Results are suggestive that improvements in pregnancy risk may come with increased luteolysis. Discussion of efforts to increase risk of ovulation after the first GnRH injection. Increased ovulation occurs in cows with low progesterone concentrations leading to increased timed AI pregnancy risk.<br /> <br /> Manipulating the reproductive cycle to achieve optimal progesterone during an Ovsynch protocol dramatically increases in fertility in lactating dairy cows.<br /> <br /> Manipulating progesterone at the first GnRH treatment of an Ovsynch protocol dramatically increased ovulatory response to GnRH but had a minimal effect on fertility. <br /> Addition of a second PGF2? treatment during an Ovsynch protocol dramatically increases fertility to timed AI, whereas reducing the duration of the protocol from 7 to 5 d does not. <br /> <br /> Cows that lost BCS before calving lost more back fat, had fewer P/AI, and had more health events during the first 120 d of lactation. <br /> <br /> Manipulating cows into a low progesterone environment during growth of the preovulatory follicle before TAI did not negatively affect fertility, pregnancy loss, or pregnancy-associated glycoprotein after TAI in Irish Holstein-Friesian dairy cows. <br /> <br /> Missouri<br /> The Missouri Show-Me Heifer program was reviewed. Since 1997, the value of replacement heifers has increased from $826 to $2944 in 2014. The program has penetrated nearly 100% of the 114 counties in Missouri and 18 other states. More than 90% of the heifers enrolled in the program are inseminated artificially. The results clearly show that heifers with reproductive tract scores (RTS) of 1 should be culled. Heifers with RTS of 3 or more have conception risks ranging from 46 to 52%. Presentation of the Missouri research involving split time AI for heifers and cows that are not in estrus at the recommended time AI breeding time. Results validate that GnRH is not needed for either heifers or suckled cows that are inseminated at the recommended timed AI time. Studies also are underway in Montana and Missouri examining the comparison of the long 14-day CIDR vs. 7-day CO-synch + CIDR program in 2-year-old cows. In summary, continued growth in the Show-Me-Select Heifer Program highlights the importance of economic incentives to drive technology utilization and improve heifer development practices statewide.<br /> The experiment was designed to evaluate timing of GnRH administration in beef heifers based on estrous status with split-time AI. Estrus was synchronized for 816 heifers across four locations using the 14-d CIDR-PG protocol (CIDR insert [1.38 gm progesterone] on d 0 with removal on d 14; 25 mg PGF2? (PG) 16 d after CIDR removal on d 30; and 100 ?g GnRH depending on treatment). Estrous detection aids (Estrotect) were applied at PG on d 30, with estrus recorded at 66 and 90 h after PG on d 33 and 34, respectively. These data suggest however that among heifers for which AI is delayed based on failure to exhibit estrus by 66 h after PG, timing of GnRH administration (66 vs 90 h after PG) may be more flexible.<br /> <br /> The experiment was designed to evaluate timing of GnRH administration in beef cows based on estrous status with split-time AI. Estrus was synchronized for 622 cows across six locations using the 7-d CO-Synch + CIDR protocol (100 ?g GnRH + CIDR insert [1.38 gm progesterone] on d 0; 25 mg PGF2? (PG) at CIDR removal on d 7; and 100 ?g GnRH depending on treatment). Estrous detection aids (Estrotect) were applied at CIDR removal and PG on d 7, with estrus recorded at 66 and 90 h after PG on d 10 and 11, respectively. These data suggest that delayed administration of GnRH to 90 h coincident with AI among cows failing to exhibit estrus by 66 h after PG results in a greater overall estrous response.<br /> <br /> Kansas<br /> Our objective was to determine the benefit of including GnRH and PGF2? (PG) as part of a presynchronization option before enrolling cows in a timed artificial insemination program. Holstein cows in one herd were assigned weekly at calving from January 2012 through August 2014 to a completely randomized design consisting of two presynchronization treatments (see figure on p. 4). Cows in the Presynch-11 (n = 290) control were administered two PGF2? injections (Presynch PG-1 and Presynch PG-2) 14 d apart starting at 39 ± 4 d postpartum (study Days 0 and 14). Cows receiving the experimental presynchronization treatment (Gsynch-11, n = 287) were treated with GnRH (Pre-GnRH) on study Day 7 and PG (Pre-PG) on study Day 14. On study Day 25, all cows were enrolled in the Ovsynch-56 timed AI program: GnRH-1 on study Day 25, PG on study Day 32, GnRH-2 on study Day 34, 56 h after PG, and timed artificial insemination (AI) on study Day 35, 16 h after GnRH-2. Pregnancy per AI at 32 and 60 d after AI did not differ between treatments, but were suppressed during summer months in both treatments to <70% of the P/AI of non-summer months. Because more than 90% of the cows were ovular as treatments were applied, the GnRH treatment of Gsynch-11 could not be assessed for its benefit in anovular cows. The Gsynch-11 presynchronization treatment performed comparably with the standard Presynch-11 program and may provide a viable presynchronization option for use before first AI in dairy herds.<br /> <br /> Illinois<br /> The experiment was conducted to determine if delaying timed AI, second GnRH injection, or both will increase pregnancy rates in nonestrous suckled beef cows exposed to the 7-d CO-synch + CIDR [GnRH (100 ?g) on d -7, PGF2? (25 mg) and CIDR removal on d 0, and a second injection of GnRH 60 h after PGF2? (d 2)] timed AI program. On day 0, all cows received an ESTROTECT™ heat detector patch. Patches score was assessed 60 h after CIDR removal and cows with activated patches assigned to the Estrus control (CON; n=80) group. The remaining cows were randomly assigned into three equal-sized groups balanced for parity, days postpartum, and BCS: Early GnRH and early AI (E-E; n=21), Early GnRH but delayed AI (E-D; n=24), or Delayed GnRH and delayed AI (D-D; n=24). Pregnancy diagnosis was performed via transrectal ultrasonagraphy 35 d after fixed-time AI. Pregnancy rates in the CON, E-E, E-D, and D-D averaged 64, 52, 42, and 50%.<br />

Publications

Peer-reviewed Journals<br /> <br /> Amundson, O. L., Fountain, T. H., Larimore, E. L., Richardson, B. N., McNeel, A .K., Wright, E. C., Keisler, D .H., Cushman, R. A., Perry, G. A., Freetly, H .C.. Post-weaning nutritional programming of ovarian development in beef heifers. J. Anim. Sci. In revision.<br /> <br /> Bridges, G. A., S. L. Lake, S. G. Kruse, S. L. Bird, B. J. Funnell, R. Aries, J. A. Walker, J. K. Grant, and G. A. Perry. 2014. Comparison of three CIDR-based fixed-time AI protocols in beef heifers. J. Anim. Sci. 92:3127-3133.<br /> <br /> Brown, B.M., J.W. Stallings, J.S. Clay and M.L. Rhoads. 2015. Milk production and composition of dairy cows that were exposed to heat stress at or around the time they were conceived. PLoS One. (in review).<br /> <br /> Brown, B.M., J.W. Stallings, J.S. Clay and M.L. Rhoads. 2015. Periconceptional heat stress of Holstein dams is associated with differences in daughter milk production during their first lactation. PLoS One. (in review).<br /> <br /> Calderón Diaz, J. A., Vallet, J. L., Lents, C. A., Nonneman, D .J., Miles, J. R., Wright, E. C., Rempel, L. A., Cushman, R. A., Freking, B. A., Rohrer, G. A., Phillips, C., DeDecker, A., Foxcroft, G., Stalder, K. Age at puberty, ovulation rate, and uterine length of developing gilts fed two lysine and three metabolizable energy concentrations from 100 d to 260 d of age. J. Anim. Sci. 2015; 93:3521-3527.<br /> <br /> Cappellozza, B. I., R. F. Cooke, M. M. Reis, R. Marques, T. A. Guarnieri Filho, G. A. Perry, D. B. Jump, K. A. Lytie, and D. W. Bohnert. 2015. Effects of protein Supplementation frequency on metabolic responses associated with reproduction of beef cows. Journal of Animal Science 93:386-394.<br /> <br /> Carvalho, P. D., M. C. Wiltbank, and P. M. Fricke. 2015. Manipulation of progesterone to increase ovulatory response to the first GnRH treatment of an Ovsynch protocol in lactating dairy cows receiving first timed artificial insemination. J. Dairy Sci. (accepted). <br /> <br /> Carvalho, P. D., M. J. Fuenzalida, A. Ricci, A. H. Souza, R. V. Barletta, M. C. Wiltbank, and P. M. Fricke. 2015. Modifications to Ovsynch improve fertility during resynchronization: Evaluation of presynchronization with GnRH 6 days before Ovsynch and addition of a second prostaglandin F2? treatment. J. Dairy Sci. (accepted). <br /> <br /> Cerny, K.L., L. Anderson, W.R. Burris, M. Rhoads, J.C. Matthews and P.J. <br /> Bridges. 2015. Form of Supplemental Selenium fed to cycling cows affects ovarian production of progesterone, but not estradiol. Theriogenology (in review).<br /> <br /> Cushman, R. A., McNeel, A. K., Souza, J. C., Britt, J. H. Applying ultrasonographic evaluation of antral follicle count to improve reproductive management in heifers. Clinical Theriogenology 2015; 7:223-227.<br /> <br /> Cushman, R. A., McNeel, A. K., Souza, J. C., Echternkamp, S. E., Britt, J. H., Freetly, H. C. Mechanisms influencing establishment of the ovarian reserve in heifers. Clinical Theriogenology 2015; 7:229-233.<br /> <br /> Cushman, R. A., R.G. Tait Jr., A.K. McNeel, E.D. Forbes, O.L. Amundson, C.A. Lents, A.K. Lindholm-Perry, G.A. Perry, J.R. Wood, A.S. Cupp, T.P.L. Smith, H.C. Freetly, and G.L. Bennett. 2015. A polymorphism in myostatin influences puberty but not fertility in beef heifers, whereas µ-calpain affects first calf birth weight. J. Anim. Sci. 93:117-126.<br /> <br /> Deaver, S.E., A.M. Felix and M.L. Rhoads. 2015. Reproductive performance of lactating dairy cattle after intrauterine administration of a prostaglandin F2? receptor antagonist four days after insemination. Theriogenology. 83(4):560-566.<br /> <br /> Freetly, H .C., Vonnahme, K. A., McNeel, A. K., Camacho, L. E., Amundson, O. L., Forbes, E. D., Lents, C. A., Cushman, R. A. The consequence of level of nutrition on heifer ovarian and mammary development. J. Anim. Sci. 2014; 92:5437-5443.<br /> <br /> Hill, S. L., G. A. Perry, V. R. G. Mercadante, G. C. Lamb, J. R. Jaeger, KC Olson, and J. S. Stevenson. 2014. Altered progesterone concentrations by hormonal manipulations before a fixed-time artificial insemination CO-Synch + CIDR program in suckled beef cows. Theriogenology 82:104-113<br /> <br /> Larimore, E. L., O. L. Amundson, S. L. Bird, B. J. Funnell, S. G. Kruse, G. A. Bridges, and G. A. Perry. 2015. Influence of estrus at fixed-time AI on accessory sperm numbers and embryonic development. J. Anim. Sci. 93: 2806-2812.<br /> <br /> Madsen, C. A., G. A. Perry, C. L. Mogck, R. F. Daly, M. D. Macneil, and T. W. Geary. 2015. Effects of Preovulatory Estradiol on Embryo Survival and Pregnancy Establishment in Beef Cows. Anim. Reprod. Sci. 158:96-103.<br /> <br /> McCracken, V.L., G. Xie, S.E. Deaver, L.H. Baumgard, R.P. Rhoads and M.L. Rhoads. 2015. Hepatic progesterone-metabolizing enzymes cytochrome P450 2C and 3A in lactating cows during thermoneutral and heat stress conditions. J. Dairy Sci. 98(5):3152-3157.<br /> <br /> McFee, R .M., Artac, R .A., Gomes, R .S., Kurz, S .G., Summers, A. F., Cushman, R .A., Wood, J. R., Cupp, A. S. Vascular endothelial growth factor A isoforms are differentially expressed prior to the LH surge, after the LH surge, and in persistent bovine dominant follicles and may be a marker of follicle health. Cell and Tissue Research. Submitted.<br /> <br /> McNeel, A. K., Cushman, R. A. Influence of puberty and antral follicle count on calving day in cross-bred beef heifers. Theriogenology 2015; 84:1061-1066.<br /> <br /> McNeel, A. K., Vallet, J. L., Snelling, W. M., Wright, E. C., Larimore, E. L., Amundson, O. L., Miles, J .R., Chase, C. C. Jr., Lents, C. A., Sonstegard, T .S., Schroeder, S. G., Wood, J. R., Cupp AS, Perry GA, Cushman RA. Effects of antral follicle count on gene expression and function of the bovine endometrium. Biol. Reprod. Submitted.<br /> <br /> Mercadante, V.R.G., L. E. Kozicki, F. M. Ciriaco, D. D. Henry, C. R. Dahlen, M. R. Crosswhite, J. E. Larson, B. E. Voelz, D. J. Patterson, G. A. Perry, R. N. <br /> <br /> Funston, T. L. Steckler, S. L. Hill, J. S. Stevenson, and G. C. Lamb. 2015. Effects of administration of prostaglandin F2? at initiation of the 7-d CO-Synch+CIDR ovulation synchronization protocol for suckled beef cows and replacement beef heifers. J. Anim. Sci. (Accepted: # E-2015-8967). <br /> <br /> Mercadante, VRG, LE Kozicki, FM Ciriaco, DD Henry, CR Dahlen, MR Crosswhite, JE Larson, BE Voelz, DJ Patterson, GA Perry, RN Funston, TL Steckler, SL Hill, JS Stevenson, and GC Lamb. 2015. Effects of administration of prostaglandin F2? at initiation of the 7-d CO-Synch+CIDR ovulation synchronization protocol for suckled beef cows and replacement beef heifers. J. Anim. Sci. (Accepted: # E-2015-8967). <br /> <br /> Perry, G. A. E. L. Larimore, B. L. Perry, and J. A. Walker. 2015. Grazing behavior of drylot developed beef heifers and the influence of post-AI Supplementation on AI pregnancy success. Prof. Anim. Sci 31:264-269.<br /> <br /> Perry, G. A., O. L. Swanson, E. L. Larimore, B. L. Perry, G. D. Djira, and R. A. Cushman. 2015. Relationship of follicle size and concentrations of estradiol among cows exhibiting or not exhibiting estrus during a fixed-time AI protocol. Dom. Anim. Endo. 48:15-20.<br /> <br /> Pinto, T. L., Nogueira, M. B., Sales, J. S., Goncalves, T .M., Carvalho, R. R., Cushman, R .A., Souza, J. C. Factors affecting pregnancy rates after ovum pick up (OPU)-derived embryo transfer in lactating Holstein recipients under tropical conditions. Ciência e Agrotecnologia 2015; In press.<br /> <br /> Pulley, S. L., and J. S. Stevenson. 2015. Five-day resynch programs in dairy cows including presynchronization and progesterone at two stages post-artificial insemination. J. Dairy Sci. 98:6243–6255.<br /> <br /> Pulley, S. L., D. H. Keisler, and J. S. Stevenson. 2015. Concentrations of luteinizing hormone and ovulatory responses in dairy cows before timed artificial insemination. J. Dairy Sci. 98:6188-6201.<br /> <br /> Rhoads, M.L., A.L. Zezeski, V.L. McCracken, G.A. Perry and A.D. Ealy. 2015. Maturation of bovine cumulus-oocyte complexes in varying concentrations of follicular fluid improves cumulus cell expansion without affecting the outcome of in vitro fertilization. Reprod. Fertil. Dev. (in review).<br /> <br /> Ricci, A., P. D. Carvalho, M. C. Amundson, R. H. Fourdraine, L. Vincenti, and P. M. Fricke. 2015. Factors associated with pregnancy-associated glycoprotein (PAG) levels in plasma and milk of Holstein cows during early pregnancy and their effect on the accuracy of pregnancy diagnosis. J. Dairy Sci. 98:2502-2514. <br /> <br /> Roberts, A.J., M.K. Petersen, and R.N. Funston. 2015. Can we build the cowherd by increasing longevity of females? J. Anim. Sci. <br /> <br /> Senturklu, S., D. G. Landblom, G. A. Perry, and T. Petry. 2015. Effect of Frame Score on Growth, Fertility, and Economics. Asian Australas. J. Anim. Sci. 28(1):69-78; HTTP//dx.doi.org/ 10.5713/ajas.13.0833.<br /> <br /> Stevenson, J. S., and G. C. Lamb. 2015. Contrasting effects of progesterone on fertility of dairy and beef cows. J. Dairy Sci. 99: Submitted.<br /> <br /> Stevenson, J. S., and S. L. Pulley. 2015. Ovulation and fertility responses to feedback effects of estradiol and progesterone on gonadotropin-releasing hormone-induced release of luteinizing hormone. J. Dairy Sci. 99: Submitted.<br /> <br /> Stevenson, J. S., S. L. Hill, G. A. Bridges, J. E. Larson, and G. C. Lamb. 2015. Progesterone status, parity, body condition, and days postpartum before estrus- or ovulation-5 synchronization in suckled beef cattle influences artificial insemination pregnancy outcomes. J. Anim. Sci 93:2111-2123.<br /> <br /> Summers, A. F., Pohlmeier, W. E., Sargent, K .M., Cole, B. D., Vinton, R. J., Kurz, S. G., McFee, R. M., Cushman, R. A., Cupp, A. S., Wood, J. R. Altered theca and cumulus oocyte gene expression, follicular arrest and reduced fertility in cows with dominant follicle follicular fluid androgen excess. PLoS ONE 2014; 9:e110683.<br /> <br /> Summers, A.F., A.D. Blair, and R.N. Funston. 2015. Impact of Supplemental protein source offered to primiparous heifers during gestation on. II. Progeny performance and carcass characteristics. J. Anim. Sci. 93:1871-1880. <br /> <br /> Summers, A.F., T.L. Meyer, and R.N. Funston. 2015. Impact of Supplemental protein source offered to primiparous heifers during gestation on. I. ADG, feed intake, calf birth weight, and rebreeding in pregnant beef heifers. J. Anim. Sci. 93:1865-1870. <br /> <br /> Tait, R. G. Jr., Cushman , R .A, McNeel, A. K., Casas, E., Smith, T. P. L., Freetly, H. C., Bennett, G. L. Casein alpha s1 and thyroglobulin genetic interaction effects on own performance, reproduction, and first calf performance traits in beef heifers selected for bigenic SNP equalization. J. Anim. Sci. Submitted.<br /> <br /> Waters, K. M., T. E. Black, V. R. G. Mercadante, G. H. L. Marquezini, N. DiLorenzo, R. O. Myer, A. T. Adesogan, and G. C. Lamb. 2015. Effects of feeding perennial peanut hay on growth, development, attainment of puberty, and fertility in beef replacement heifers. Prof. Anim. Sci. 31:40-49. <br /> <br /> Xie, M., S. McCoski, S. Johnson, M. Rhoads and A. Ealy. 2015. Combinatorial effects of epidermal growth factor, fibroblast growth factor 2, and insulin-like growth factor 1 on trophoblast cell proliferation and embryogenesis in cattle. Reprod. Fertil. Dev. (accepted).<br /> <br /> Abstracts/Posters/Professional Presentations<br /> <br /> Al Naib, A., A.Y. Wood, H.L.M. Tucker, C.M. Parsons, V.L. McCracken, A.L. Zezeski, S.E. Deaver, B.M. Brown, R.M. Akers and M.L. Rhoads. 2015. Effects of Tamoxifen on pre-pubertal heifer reproductive tissues: Potential for disruption of tract development through alteration of related signaling pathways. J. Dairy Sci. 98(Suppl 2):545.<br /> <br /> Amundson, O. L., T. G. Fountain, E. L. Larimore, B. N. Richardson, A. K. McNeel, E. C. Wright-Johnson, D. H. Keisler, R. A. Cushman, G. A. Perry, and H. C. Freetly. 2015. Post-weaning nutritional programming of ovarian development in beef cattle. J. Anim. Sci. Midwest ASAS<br /> <br /> Bishop, BE, JM Thomas, JM Abel, MR Ellersieck, SE Poock, MF Smith, and DJ Patterson. 2015. Timing GnRH administration based on estrous response in beef heifers following administration of the 14-d CIDR-PG protocol with split-time AI. J. Anim. Sci. 93, Suppl. s3:231.<br /> <br /> Black, D.N., M.R. Crosswhite, B.W. Neville, and C.R. Dahlen. 2015. Impact of managing cow-calf pairs on pasture or in a dry lot during a 10 day synchronization period on reproductive performance and weight change in cows and their calves. J. Anim. Sci. 93(Suppl. 2):188.<br /> <br /> Bridges, P.J., K.L. Cerny, M. Rhoads, L.H. Anderson, W.R. Burris and J.C. Matthews. 2015. Form of selenium in free-choice mineral mixes affects ovarian production of progesterone but not estradiol in cycling beef cows. J. Anim. Sci. 93(Suppl s3):88.<br /> <br /> Mogck, C.L., C. A. Madsen, T. W. Geary, and G. A. Perry. 2015. Role of exogenous estradiol in initiation of estrus and induction of an LH surge. J. Anim. Sci. Midwest ASAS.<br /> <br /> Carvalho, P. D. and P. M. Fricke. 2015. Association between changes in body condition score and back fat thickness during the transition period with fertility and health events in Holstein cows. J. Dairy Sci. 98(Suppl. 2):102. <br /> <br /> Carvalho, P. D., M. C. Wiltbank, and P. M. Fricke. 2015. Hormonal manipulation of progesterone before initiation of an Ovsynch protocol to increase ovulatory response to the first GnRH treatment in Holstein cows. J. Dairy Sci. 98(Suppl. 2):811.<br /> <br /> Carvalho, P. D., M. C. Wiltbank, and P. M. Fricke. 2015. Progesterone concentration at each treatment during an Ovsynch protocol affects fertility to timed AI in Holstein cows. J. Dairy Sci. 98(Suppl. 2):92. <br /> <br /> Carvalho, P. D., M. J. Fuenzalida, V. G. Santos, A. Ricci, M. C. Wiltbank, and P. M. Fricke. 2015. Progesterone concentration at initiation of an Ovsynch protocol and a second prostaglandin F2? treatment affect luteal regression and fertility to timed AI in Holstein cows. J. Dairy Sci. 98(Suppl. 2):811.<br /> <br /> Chase, Jr., C. C., R. A. Cushman, A. K. McNeel, E. C. Wright, O. L. Amundson, E. L. Larimore, B. N. Richardson, G. A. Perry, S. C. Tenley, J. R. Wood, A. S. Cupp, J. L. Vallet, D. D. Sypherd, and J. R. Miles. 2015. IN Vitro fertilization (IVF) from low or high antral follicle count pubertal beef heifers. J. Anim. Sci. <br /> <br /> Ciriaco, F. M., D. D. Henry, V. R. G. Mercadante, T. Schulmeister, G. C. Lamb, and N. DiLorenzo. 2014. Evaluation of a mixture of crude glycerol and molasses as an energy Supplement for beef cattle consuming bermudagrass hay. J. Anim. Sci 92(E-Suppl. 2):353 (Abstr.)<br /> <br /> Crosswhite, M.R., B.W. Neville, J.C. Rodgers, J.T. Seeger, and C.R. Dahlen. 2015. Impact of prebreeding vaccination with modified-live or inactivated viral vaccines on subsequent reproductive performance in crossbred beef females. J. Anim. Sci. 93(Suppl. 2):170.<br /> <br /> Crouse, M.S., K.J. McLean, L.P. Reynolds, C.R. Dahlen, B.W. Neville, P.P. Borowicz, and J.S. Caton. 2015. Nutrient transporters in bovine utero-placental tissues on days 16 to 50 of gestation. 2015 American Society of Animal Science Western Section Meeting.<br /> <br /> Cushman, R.A., K. McNeel, E. C. Wright, O. L. Amundson, S. C. Tenley, E. L. Larimore, B. N. Richardson, C. C. Chase Jr., G. A. Perry, and A. S. Cupp. 2015. Relationship between pre-weaning gain, age at puberty, and reproductive tract development in Angus heifers. J. Anim. Sci. Midwest ASAS.<br /> <br /> da Silva, A.G. and R.N. Funston. 2015. Economic aspects of rebreeding non-pregnant cows. J. Anim. Sci. 93(e-Suppl. 2).<br /> <br /> Dahlen, C.R. and C.L. Stoltenow. 2015. The PregCard study; assessing the impact of routine management strategies on reproductive performance of beef herds in the upper Great Plains. 2015 American Society of Animal Science Western Section Meeting.<br /> <br /> Fricke, P. M. 2015. 30:30 - How to achieve a 30% preg rate in a 30,000 lb. dairy herd. Zoetis Reproduction Meetings. August 26-27, Grand Rapids, MI and Fort Wayne, IN.<br /> <br /> Fricke, P. M. 2015. 30:30 - How to achieve a 30% preg rate in a 30,000 lb. dairy herd. Zoetis Pacific Coast Veterinary Meeting. April 10, Pismo Beach, CA. <br /> <br /> Fricke, P. M. 2015. 30:30 - How to achieve a 30% preg rate in a 30,000 lb. dairy herd. Central Plains Dairy Expo Zoetis preconference symposium. March 24, Sioux Falls, SD. <br /> <br /> Fricke, P. M. 2015. 4 Keys to reproductive success. Form-A-Feed Professional Dairy Conference, January 23, Morton, MN.<br /> <br /> Fricke, P. M. 2015. Can dairy cows eat their way to better reproduction? Form-A-Feed Professional Dairy Conference, January 22, Morton, MN. <br /> <br /> Fricke, P. M. 2015. Double-Vision: Management of twinning in dairy cows. Proc. AABP annual conference, September 19, New Orleans, LA.<br /> <br /> Fricke, P. M. 2015. Factors associated with pregnancy-associated glycoprotein levels in blood and milk of Holstein cows during early pregnancy and their impact on the accuracy of pregnancy diagnosis. IDEXX Advisory Board meeting, May 21-22, Westbrook, ME. <br /> <br /> Fricke, P. M. 2015. Five keys to reproductive success. Proc. Georgia Milk Producers Conference, January 13, Savannah, GA.<br /> <br /> Fricke, P. M. 2015. New Technologies to manage reproduction in dairy cows. Zoetis Reproduction Meetings. August 26-27, Grand Rapids, MI and Fort Wayne, IN.<br /> <br /> Fricke, P. M. 2015. Physiology and treatment of anovular and cystic dairy cows. Merck Animal Health Conference, May 29, Stare Jablonki, Poland.<br /> <br /> Fricke, P. M. 2015. Reproductive challenges of high producing dairy cows. Proc. North American Veterinary Conference. January 19, Orlando, FL. <br /> <br /> Fricke, P. M. 2015. Strategies for nonpregnancy diagnosis. Proc. North American Veterinary Conference. January 19, Orlando, FL.<br /> <br /> Fricke, P. M. 2015. Strategies for submitting cows for first insemination. Proc. North American Veterinary Conference. January 19, Orlando, FL.<br /> <br /> Fricke, P. M. 2015. Strategies for submitting cows for second and greater insemination. Proc. North American Veterinary Conference. January 19, Orlando, FL.<br /> <br /> Fricke, P. M. 2015. 30:30 - How to achieve a 30% preg rate in a 30,000 lb. dairy herd. Zoetis Dairy Meeting, May 3, Gettysburg, PA.<br /> <br /> Fricke, P. M., A. Ricci, and P. D. Carvalho. 2015. Factors associated with pregnancy-associated glycoprotein levels in plasma and milk of Holstein cows during early pregnancy and their impact on the accuracy of pregnancy diagnosis. Proc. Four-State Dairy Nutrition & Management Conference, June 10, Dubuque, IA, pp. 57-62.<br /> <br /> Fricke, P. M., A. Ricci, P. D. Carvalho, and M. C. Amundson. 2015. Milk vs. Blood – which is best for PAG pregnancy prediction? Proc. 12th Western Dairy Management Conference, March 4-5, Reno, NV, pp. 177-185. <br /> <br /> Fricke, P. M., A. Valenza, G. Lopes Jr., M. C. Amundson, and J. O. Giordano. 2015. Expression and detection of estrus in dairy cows: The role of activity monitoring systems. Proc. Georgia Milk Producers Conference, January 14, Savannah, GA.<br /> <br /> Fuenzalida, M. J., P. D. Carvalho. M. C. Wiltbank, P. L. Ruegg, and P. M. Fricke. 2015. Etiology of early pregnancy losses in Holstein dairy cows based on serum pregnancy-associated glycoprotein and progesterone concentrations. J. Dairy Sci. 98(Suppl. 2):426. <br /> <br /> Funston, R.N., E.E. Grings, A.J. Roberts, and B.T. Tibbitts. 2015. Selection of a calving season. J. Anim. Sci. 93(e-Suppl. 2, invited). <br /> <br /> Geppert, T. C. G. A. Perry and P. J. Gunn. 2015. Effects of Supplementing excess amounts of rumen undegradable protein on ovarian function of beef cows consuming low quality forage. J Anim Sci<br /> <br /> Geppert, T. C., G. A. Perry and P. J. Gunn. 2015. Effects of excess dietary MP from corn gluten meal or soybean meal on ovarian function of beef cows consuming low quality forage. J. Anim. Sci. <br /> <br /> Geppert, T.C., A. M. Meyer, G. A. Perry and P. J. Gunn. 2015. Relationship between circulating plasma amino acid profile and reproductive function around the time of ovulation in beef cows. J. Anim. Sci. <br /> <br /> Gunn, P.J., A. L. Lundberg, R. A. Cushman, H. C. Freetly, O. L. Amundson, J. A. Walker, and G. A. Perry. 2015. Effect of circulating blood urea nitrogen concentrations on reproductive efficiency in beef heifers and cows. J. Anim. Sci.<br /> <br /> Henry, D. D., F. M. Ciriaco, V. R. G. Mercadante, T. Schulmeister, D. Demeterco, A. Marin, G. C. Lamb, and N. DiLorenzo. 2014. Effects of feeding chitosan on nutrient digestibility in beef heifers. J. Anim. Sci 92(E-Suppl. 2):326 (Abstr.)<br /> <br /> Henry, D. D., V. R. G. Mercadante, F. M. Ciriaco, P. M. Mercadante, T. Schulmeister, N. DiLorenzo, and G. C. Lamb. 2014. Potential bull buyers perceive increased value to their operations when purchasing bulls from the Florida Bull Test. J. Anim. Sci 92(E-Suppl. 2):517 (Abstr.)<br /> <br /> Hill, S. L., D. M. Grieger, KC Olson, J. R. Jaeger, C. R. Dahlen, S. R. Underdahl, G. A. Bridges, J. E. Larson, J. K. Ahola, M. C. Fischer, G. A. <br /> Perry, T. L. Steckler, W. D. Whittier, J. F. Currin, and J. S. Stevenson. 2015. Using estrus-detection patches to optimally time artificial insemination (AI) improved pregnancy rates in suckled beef cows in a timed AI program. J. Anim. Sci. 93(E-Suppl. s3):90 (Abstr.).<br /> <br /> Kincheloe, J.K., R.N. Funston, A.D. Blair, K. Olson. 2015. Impact of maternal protein restriction in first-calf heifers during mid- to late-gestation on dam and suckling calf performance through weaning. Proc. West. Sec. Am. Soc. Anim. Sci. 66: <br /> <br /> Manthey, A. K., J. L. Anderson, and G. A. Perry. 2015. Evaluation of growth performance in dairy heifers fed reduced fat distillers grains in replacement of forage in limit-fed rations. J. Anim. Sci.<br /> <br /> Manthey, A. K., J. L. Anderson, G. A. Perry, and D. H. Keisler. 2015. Metabolic profile and onset of puberty in dairy heifers fed reduced-fat distillers grains in replacement of forage. J Anim Sci.<br /> <br /> McNeel, A. K., E. L. Larimore, O. L. Amundson, C. C. Chase Jr, G. A. Perry, and R. A. Cushman. 2015. Differences in antral follicle counts in pubertal Angus cattle are associated with differences in the uterine transcriptome during the late luteal phase. Society for the Study of Reproduction<br /> <br /> Mercadante, V. R. G., D. D. Henry, F. M. Ciriaco, P. M. Mercadante, J. C. Rodgers, N. DiLorenzo, and G. C. Lamb. 2014. Development and utilization of the AI Cowculator: A decision-aid application to determine whether to utilize fixed-time artificial insemination (TAI) or purchase herd sires for natural service. J. Anim. Sci 92(E-Suppl. 2):524 (Abstr.)<br /> <br /> Mercadante, V. R. G., L. E. Kozicki, F. M. Ciriaco, D. D. Henry, C. R. Dahlen, R. N. Funston, J. E. Larson, G. A. Perry, T. L. Steckler, and G. C. Lamb. 2014. Effects of administration of prostaglandin F2? at initiation of the 7-d CO-Synch + CIDR estrus synchronization protocol for replacement beef heifers. J. Anim. Sci 92(E-Suppl. 2):261 (Abstr.) <br /> <br /> Mercadante, V. R. G., L. E. Kozicki, F. M. Ciriaco, D. D. Henry, C. R. Dahlen, J. E. Larson, B. E. Voelz, D. J. Patterson, G. A. Perry, T. L. Steckler, J. S. Stevenson, and G. C. Lamb. 2014. Effects of administration of prostaglandin F2? at initiation of the 7-d CO-Synch+CIDR estrus synchronization protocol for suckled beef cows. J. Anim. Sci 92(E-Suppl. 2):269 (Abstr.)<br /> <br /> Nielson, H.R., D.J. Kelly, and R.N. Funston. 2015. Comparison of TAI at GnRH injection and delayed insemination of non-estrus beef heifers. J. Anim. Sci. 93(e-Suppl. 2). <br /> <br /> Nielson, H.R., R.V. Anderson, and R.N. Funston. 2015. Effect of MGA vs CIDR estrus synchronization on estrus response and pregnancy rates in 311 d old beef heifers. J. Anim. Sci. 93(e-Suppl. 2). <br /> <br /> Nielson, H.R., T.L. Meyer, and R.N. Funston. 2015. Effect of post-weaning heifer development on pregnancy rates and subsequent feed efficiency as a pregnant first calf heifer J. Anim. Sci. 93(e-Suppl. 2). <br /> <br /> Northrop, E. J., O. L. Amundson, B. N. Richardson, A. K. McNeel, R. A. Cushman, and G. A. Perry. 2015. Influence of estrus expression prior to fixed-time AI on embryo survival to maternal recognition of pregnancy. J. Anim. Sci. <br /> <br /> Perry, G.A., O. L. Amundson, and R. A. Cushman. 2015. Use of ultrasonography to make management decisions. J. Anim. Sci. <br /> <br /> Rasby, R.J., and R.N. Funston. 2015. Nutrition and management of cows – Supplementation and feed additives. J. Anim. Sci. 93(e-Suppl. 2, invited).<br /> <br /> Richardson, B.N., E. L. Larimore, J. A. Walker, M. Utt, M. DeJarnette, and G.A. Perry. 2015. Comparison of fresh-extended and conventional semen on fertility when varying the interval from CIDR removal to insemination in a 7-day CO-Synch + CIDR protocol. J. Anim. Sci.<br /> <br /> Roberts, A.J., E.E. Grings, M.K. Peterson, R.N. Funston. 2015. Developmental programming of fertility. J. Anim. Sci. 93(e-Suppl. 2, invited). <br /> <br /> Rocha, L., J. S. Stevenson, and L. G. D. Mendonça. 2015. Presynchronization strategy using prostaglandin F2? and GnRH to improve fertility in a resynchronization program based on detection of estrus. J. Dairy Sci. 98(E-Suppl. 2):91-92 (Abstr.).<br /> <br /> Safranski, T., M.C. Lucy, J.N. Rhoades, M. Estienne, J.G. Wiegert, M. Rhoads, R.P. Rhoads, L.H. Baumgard and J.W. Ross. 2015. Reproductive performance of gilts having developed in heat stressed dams. J. Anim. Sci. 93(Suppl 2):85.<br /> <br /> Santos, V. G., P. D. Carvalho, C. Maia, B. Carneiro, A. Valenza, E. M. Bettencourt, and P. M. Fricke. 2015. Effect of decreasing the duration of a PRID-synch protocol and addition of a second prostaglandin F2? treatment on fertility after resynchronization of ovulation in lactating Holstein cows. J. Dairy Sci. 98(Suppl. 2):543. <br /> <br /> Schook, M.R., P. L. Steichen, V. R. G. Mercadante, G. C. Lamb, B. W. Neville, and C. R. Dahlen. 2014. Effects of breeding system of origin (natural service or AI) on growth, attainment of puberty, and pregnancy rates in crossbred beef heifers. J. Anim. Sci 92(E-Suppl. 2):68 (Abstr.)<br /> <br /> Steichen, P. L., S. I. Klein, Q. Larson, K. M. Bischoff, V. R. G. Mercadante, G. C. Lamb, C. S. Schauer, B. W. Neville, and C. R. Dahlen. 2014. Effects of artificial insemination and natural service breeding systems on calving characteristics and weaning weights of resultant progeny. J. Anim. Sci 92(E-Suppl. 2):263 (Abstr.)<br /> <br /> Stevenson, J. S., and G. C. Lamb. 2015. Contrasting effects of progesterone on fertility of dairy and beef cows. J. Dairy Sci. 98(E-Suppl. 2):306 (Abstr.).<br /> <br /> Thomas, JM, BE Bishop, JM Abel, JE Decker, SE Poock, DS Brown, MF Smith, and DJ Patterson. 2015. The Missouri Show-Me-Select Replacement Heifer Program: Improving heifer development practices and increasing technology utilization through economic incentives. J. Anim. Sci. 93, Suppl. s3:526.<br /> <br /> Thomas, JM, SE Poock, MR Ellersieck, MF Smith, and DJ Patterson. 2014. Delayed insemination of non-estrous beef heifers and cows when using conventional semen in timed artificial insemination. J. Anim. Sci. 92:4189-4197.<br /> <br /> Tibbitts, B.T., C.A. Welchons, R.G. Bondurant, F.H. Hilscher, J.C. MacDonald, R.N. Funston. 2015. Effects of Supplemental energy and protein source on performance of steers grazing irrigated corn residue. J. Anim. Sci. 93(e-Suppl. 2). <br /> <br /> Valenza, A., P. M. Fricke. 2015. Expression and detection of estrus in dairy cows: The role of new technologies. Ceva publication.<br /> <br /> Voelz, B. E., L. Rocha, F., J. S. Stevenson, and L. G. D. Mendonça. 2015. Treatment of primiparous lactating dairy cows with GnRH before first insemination during summer heat stress. J. Dairy Sci. 98(E-Suppl. 2):91 (Abstr.).<br /> <br /> Wiegert, J.G., R.H. Preisser, M.C. Lucy, T.J. Safranski, R.P. Rhoads, J.W. Ross, L.H. Baumgard, M.J. Estienne and M.L. Rhoads. 2015. Effects of in utero heat stress on subsequent lactational performance of gilts and transgenerational effects on offspring. J. Anim. Sci. 93(Suppl 2):166.<br /> <br /> Extension Reports/Publications<br /> <br /> Crouse, M.S., K.J. McLean, L.P. Reynolds, C.R. Dahlen, B.W. Neville, P.P. Borowicz, and J.S. Caton. 2015. Nutrient transporters in bovine utero-placental tissues on days 16 to 50 of gestation. Proc. West. Sec. Amer. Soc. Anim. Sci. 66:44-47.<br /> <br /> Dahlen, C.R. and C.L. Stoltenow. 2015. The PregCard study; assessing the impact of routine management strategies on reproductive performance of beef herds in the upper Great Plains. Proc. West. Sec. Amer. Soc. Anim. Sci. 66:151-154.<br /> <br /> Dahlen, C.R., and G.L Stokka. 2015. Bull Breeding Soundness Examinations. NDSU AS-1755. Available at http://www.ag.ndsu.edu/pubs/ansci/livestoc/as1755.pdf<br /> <br /> Dahlen, C.R., D.N. Black, and M.R. Crosswhite. 2015. Maximizing Pregnancy Rates to AI. NDSU AS-1749. Available at: http://www.ag.ndsu.edu/pubs/ansci/livestoc/as1749.pdf<br /> <br /> Patterson, DJ, and JE Decker. 2015. Phenotypic data collection for reproductive traits in replacement beef heifers. In: Proceedings, Beef Improvement Federation. June 10, Biloxi, MS. <br /> <br /> Patterson, DJ, JM Thomas, BE Bishop, JM Abel, and MF Smith. 2014. Control of estrus and ovulation in heifers. In: Proceedings, Applied Reproductive Strategies in Beef Cattle. October 7-8, Stillwater, OK. pp. 75-109.<br /> <br /> Patterson, DJ, JM Thomas, BE Bishop, JM Abel, and MF Smith. 2015. Control of estrus and ovulation in heifers. In: Proceedings, Applied Reproductive Strategies in Beef Cattle. August 17-88, Davis, CA. pp. 36-67. In: Proceedings, Applied Reproductive Strategies in Beef Cattle. August 17-88, Davis, CA. pp. 67-105.<br /> <br /> Patterson, DJ, JM Thomas, BE Bishop, JM Abel, JE Decker, and MF Smith. 2015. Control of estrus and ovulation in beef cows. In: Proceedings, Applied Reproductive Strategies in Beef Cattle. August 17-18, Davis CA. pp. 67-105.<br /> <br /> Patterson, DJ, JM Thomas, JM Abel, BE Bishop, JE Decker, and MF Smith. 2014. Control of estrus and ovulation in beef cows. In: Proceedings, Applied Reproductive Strategies in Beef Cattle. October 7-8, Stillwater, OK. pp. 111-154.<br /> <br /> Schnabel, R.D., .JF. Taylor, A.L. Van Eenennaam, D.S. Brown, M.F. Smith, M.M. Rolf, M.D. MacNeil, B.P. Kinghorn, and D.J. Patterson. Reducing the incidence of early embryonic mortality in beef cattle. Proceedings, 10th World Congress of Genetics Applied to Livestock Production. August, 2014. Vancouver, BC, Canada.<br /> <br /> Schook, M.R., P.L. Steichen, V.R.G. Mercadante, G.C. Lamb, B.W. Neville, and C.R. Dahlen. 2014. Effects of breeding system of origin (natural service or artificial insemination) on growth, attainment of puberty, and pregnancy rates in crossbred beef heifers. North Dakota Beef Report:46-48.<br /> <br /> Smith, M..F, G.A. Perry, K.G. Pohler, R.M. Wallace, SE Dickinson, AO Gatea, and DJ Patterson. 2014. Physiological principles underlying synchronization of estrus. In: Proceedings, Applied Reproductive Strategies in Beef Cattle. October 7-8, Stillwater, OK. pp. 22-48.<br /> <br /> Thomas, J.M., and D..J Patterson. 2014. The importance and challenges of a beef sire fertility system. In: Proceedings, 25th National Association of Animal Breeders (NAAB) Annual Convention and Technical Conference. September 25-26, Green Bay, WI. pp. 27-45.<br /> <br /> Articles in the Popular Press (non-peer reviewed)<br /> <br /> Steckler T. L. Aug 2015. Health Considerations When Weaning Calves. Mid-America Farmer Grower<br /> <br /> Steckler T. L. Dec 2014. Limping in Cattle May Indicate Foot Rot. Mid-America Farmer Grower<br /> <br /> Steckler T. L. Dec 2014. Livestock Care Increases as Temperatures Drop. Illinois AgriNews<br /> <br /> Steckler T. L. Jan 2015. Management Tips for the Calving Season. Mid-America Farmer Grower<br /> <br /> Steckler T. L. July 2015. Alternative Grazing. Mid-America Farmer Grower<br /> <br /> Steckler T. L. July 2015. Its West Again this Year. Illinois AgriNews<br /> <br /> Steckler T. L. Mar 2015. Is he really earning his keep or just getting by? Mid-America Farmer Grower<br /> <br /> Steckler T. L. May 2015. Ticks and flies – the scourge of man and cattle alike! Mid-America Farmer Grower<br /> <br /> Steckler T. L. Nov 2014. Watch for Cold Stress in Cattle This Winter. Mid-America Farmer Grower<br /> <br /> Steckler T. L. Sept 2015. Consider Grazing Cornstalks. Mid-America Farmer Grower<br /> <br /> Stevenson, J. S. 2014. Five-day Ovsynch deserves a good look. Hoard’s Dairyman 159:744.<br /> <br /> Stevenson, J. S. 2014. Heat detection pays dividends. Hoard’s Dairyman 159:649.<br /> <br /> Stevenson, J. S. 2014. Timed A.I. marks 20-year anniversary. Hoard’s Dairyman 159:580.<br /> <br /> Stevenson, J. S. 2015. Do larger doses improve Ovsynch? Hoard’s Dairyman 160:162.<br /> <br /> Stevenson, J. S. 2015. Keep A.I. breeding benchmarks easy. Hoard’s Dairyman 160:506.<br /> <br /> Stevenson, J. S. 2015. More on mastitis and fertility. Hoard’s Dairyman 160:414.<br /> <br /> Stevenson, J. S. 2015. New milk and blood pregnancy tests can improve A.I. Hoard’s Dairyman 160:15.<br /> <br /> Stevenson, J. S. 2015. Refining your timed AI program. Hoard’s Dairyman 160:93.<br /> <br /> Stevenson, J. S. 2015. What about progesterone? Hoard’s Dairyman 160:345.<br /> <br /> Stevenson, J. S. 2015. When to breed or not to breed. Hoard’s Dairyman 160:256.<br /> <br /> Student Theses and/or Dissertations<br /> <br /> Amundson, O. 2015. Post-weaning nutritional programming of ovarian development and role of elevated blood urea on uterine environment and pregnancy success in beef heifers. MS thesis, South Dakota State University.<br /> <br /> Crego, S. 2015. Factors that impact pregnancy success with sexed-semen in dairy cows. MS thesis, South Dakota State University.<br /> <br /> McCracken, V. 2015. The effects of dietary fructose and fat on the reproductive parameters of prepubertal and pregnant gilts. MS thesis, Virginia Tech.<br /> <br /> Zezeski, A. 2014. Utilization of early weaning and intrafollicular insemination as methods to improve the reproductive performance of cattle. MS thesis, Virginia Tech.<br /> <br /> Funding (include grants and contracts)<br /> <br /> 1. Missouri. Facilitating expansion and genetic improvement of the Missouri beef cow herd through use of sex-sorted semen in timed artificial insemination of beef heifers. University of Missouri Commercial Agriculture. 2015. $25,000. PI.<br /> <br /> 2. Missouri. Database enhance: Missouri Show-Me-Select Replacement Heifer program. University of Missouri Commercial Agriculture. 2015. $25,000. Co-PI.<br /> <br /> 3. Missouri. University of Missouri Thompson Research Center. 2015. Research Incentive Grant. $15,000. PI.<br /> <br /> 4. Missouri. Multistate Project NC-1201: Methods to Increase Reproductive Efficiency in Cattle. 2015. USDA. $10,000 PI.<br /> <br /> 5. Missouri. Identification and management of alleles impairing heifer fertility while optimizing genetic gain in Angus cattle. USDA-NIFA-AFRI #2013-68004-20364 (01/01/2013 to 12/31/2017; $2,997,040). PD.<br /> <br /> 6. Kansas. Enhancing Expression of Estrus before Artificial Insemination of Lactating Dairy Cows. Kansas Dairy Commission. 2014-201. $5,000. PI.<br /> <br /> 7. Kansas. Administration of Prostaglandin F2? at Timed Artificial Insemination of Lactating Dairy Cows to Increase Pregnancy Outcomes. Select Sires. 2015-2016. $8,800. Co-PI.<br /> <br /> 8. Kansas. The Effect of Multimin Injectable Trace Mineral Solution on Semen Quality of Young Breeding Beef Bulls. Multimin. 2014-2015. $25,000. Co-PI.<br /> <br /> 9. Kansas. Delayed Insemination of Beef Cows Not Yet in Estrus by 60 hours after CIDR Insert Removal and Lutalyse Injection. Zoetis. $5,000. PI.<br /> <br /> 10. Kansas. Multistate Project NC-1201: Methods to Increase Reproductive Efficiency in Cattle. USDA Hatch. 2014-2015. $10,000. PI.<br /> <br /> 11. Wisconsin. Manipulating progesterone to increase fertility to timed AI in lactating dairy cows. USDA NC-1201 Regional Research project/Hatch project. $123,481. PI<br /> <br /> 12. Wisconsin. Ceva Animal Health. 2014. Unrestricted gift. $10,000. <br /> <br /> 13. Wisconsin. Genetic, nutritional and management approaches to improve fertility in lactating dairy cattle. Ireland Department of Agriculture, Food and the Marine. 12-11-2013 to 11-30-2017. €961,125.40. CoPI.<br /> <br /> 14. Wisconsin. Strategies to improve reproductive performance in the beef cattle industry. USDA NIFA NLGCA proposal. 11-01-2013 to 10-31-2016. UW subcontract: $150,328. CoPI.<br /> <br /> 15. Florida. Fetal Versus Maternal Contributions of Bos indicus genetics to offspring growth. USDA-NIFA AFRI. 2015-2017, $450,000.<br />

Impact Statements

1. Proper ovarian steroid production is crucial for fertility in cows; however, the influence of specific steroids and the mechanisms of action remain unclear. Research performed by ARS researchers at Clay Center, NE, in collaboration with the University of Nebraska at Lincoln and the Federal University of Lavras in Lavras, Brazil indicated that improper ovarian function led to altered steroid production that was associated with altered gene abundance in the egg. This altered gene abundance in the egg can lead to decreased fertility. Attempts to shift the profile of steroid hormones produced did not improve fertility, but did provide evidence that estrogen may be the steroid hormone most likely to improve fertility in beef cows. This lack of an improvement in fertility indicates that improper steroid production may be a function of poor egg quality and not a contributor to poor egg quality, thereby explaining why shifting the steroid profile does not improve the fertility.
2. Caution must be taken when using genetic markers to increase production efficiency to insure that selection for production does not cause a decline in fertility in the cow herd. A change in the sequence of the myostatin gene that is associated with greater rib eye area and decreased fat depth in steers was determined to be associated with an increased age at puberty in heifers by ARS researchers at Clay Center, NE. This gene variant did not change the percent of heifers that became pregnant and did not delay the date of calving. Results indicate that selection for this genetic marker alone may not greatly impair reproductive function in the cow herd; however, the interaction of this gene with other genetic markers for production efficiency and the influence of this gene on reproductive longevity remain to be evaluated.
3. 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.
4. Selecting only cows that have exhibited estrus before timed artificial insemination can improve pregnancy success.
5. Split-time artificial insemination (STAI) involves a single insemination performed at one of two time points and allows beef heifers to be managed based on estrous status following the administration of an estrus synchronization protocol.
6. When considering STAI in beef heifers after synchronization of estrus with the 14-day CIDR-PG protocol? o It is not necessary to administer GnRH to heifers that express estrus prior to 66 hours after PG o GnRH may be administered concurrent with AI 24 hours later for heifers that failed to express estrus prior to 66 hours after PG
7. It is not necessary to administer GnRH to heifers that express estrus prior to 66 hours after PG ? GnRH may be administered concurrent with AI 24 hours later for heifers that failed to express estrus prior to 66 hours after PG
8. Based on the case study at the University of Florida, after six years of exposure to applied reproductive technologies calves were valued at $169 per calf more than prior to incorporating reproductive management technologies. Therefore, in FL alone, if every cow herd were to incorporate reproductive management tools such as estrus synchronization, AI, and reducing the length of the breeding season the overall impact would exceed $150 million per year.
9. In previous reports the AI Cowculator was introduced. Based on economic research, the AI Cowculator is a smartphone application for Android and iPhone/iPad users that may be downloaded free of charge and is a decision aid tool to assist producers to determine whether they should consider TAI rather than purchasing herd sires for their cow herds. This application has been downloaded by 3,429 people in 42 states and six countries. In addition, the excel version of the economic model has been downloaded 242 times by industry professionals. The Facebook page developed as a support Supplement to the AI Cowculator has received 430 ?likes? and reaches between 50 and 900 readers for every post.
10. We continue to monitor real-time pregnancy rate and bull breeding soundness examination data in the Upper Great Plains. Our system of monitoring and reporting enabled out team and participating veterinarians to provide individual consultation to over 2,000 beef operations with data reported from over 300,000 beef females and over 12,000 breeding bulls.
11. Low input heifer development systems have resulted in a significant savings per pregnant heifer over conventional heifer development systems.
12. Synchronization systems decrease date of conception during the breeding season.
13. A system of monitoring and reporting results of bull breeding soundness examinations was developed and implemented successfully.
14. Using prostaglandin F2? at the initiation of a natural service breeding system improved final pregnancy rates in cattle with low body condition managed on expansive pasture
15. The centralized data base developed in support of the Show-Me-Select Replacement Heifer Program facilitates tracking of reproductive data on replacement beef heifers generated from the program. ? The Show-Me-Select Replacement Heifer Program draws on the fundamentals upon which Extension and the Land Grant System were founded: the use and application of what we know to create knowledge. ? The Show-Me Select Replacement Heifer Program facilitates transfer of science-based knowledge to beef producers in Missouri enabling participants to make practical production and management decisions based on economics.

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Report Information

Participants

Attendees:
Cooke, Reinaldo – Oregon State University
Cushman, Robert – US-MARC
Dahlen, Carl – North Dakota State Univ.
Fricke, Paul – University of Wisconsin
Lamb, Cliff – University of Florida
Mercadante, Vitor – Virginia Tech
Patterson, David – University of Missouri
Perry, George – South Dakota State Univ.
Steckler, Teresa, University of Illinois
Stevenson, Jeffrey – Kansas State University
Thomas, Jordan – University of Missouri
Turzillo, Adele -- USDA NIFA

Excused:
Funston, Rick – University of Nebraska (schedule conflict)
Gunn, Patrick – Iowa State University (ill)
Hamernik, Deb – Administrative Adviser (out of the country on assignment for ASAS)
Larson, Jamie – Mississippi State University (schedule conflict)

Brief Summary of Minutes

Accomplishments

<p>Accomplishments<br />Objective 1. To determine mechanisms that regulate reproductive processes impacting production efficiency in cattle.</p><br /> <p>Nebraska<br />Comparison of timed insemination vs. modified estrus- detection protocol in beef heifers. Angus-based, crossbred heifers (n = 972, 346 kg &plusmn; 14 kg) were assigned to either a fixed timed AI (FTAI) protocol or modified estrus detection with fixed-time AI (M) to evaluate synchronization, conception, and pregnancy rates. During the prebreeding development period, heifers were fed to achieve a target of 60 &plusmn; 5% mature BW at breeding. Heifers were synchronized via melengestrol acetate-prostaglandin (MGA-PG) protocol and received an estrus detection aid (patch) at PG administration. A patch score was recorded for each heifer at AI to reflect what percentage of rub-off coating had been removed. Heifers in the FTAI treatment received 2 mL GnRH injection and were AI 72 &plusmn; 2 h following PG. Heifers in MTAI treatment were observed for estrus at 58 &plusmn; 2 and 70 &plusmn; 2 h after PG. Approximately 72 &plusmn; 2 h after PGF2, heifers in MTAI were AI in the following order: heifers in estrus at 58 h post-PG, heifers in estrus at 70 h post-PG, and heifers not expressing estrus at either estrus observation. Heifers not expressing estrus received GnRH at AI. Pregnancy was determined via transrectal ultrasonography. Heifers exhibiting estrus had greater (P &lt; 0. 01; 71 and 66 &plusmn; 5% for FTAI vs. MTAI, respectively) AI conception rates than heifers not expressing estrus in both FTAI and MTAI treatments vs. 47 and 53 &plusmn; 9% AI conception rates in nonestrus heifers for FTAI and MTAI, respectively. However, overall AI conception rate (62 &plusmn; 5%, P = 0. 49) and final pregnancy rates were similar (P = 0. 98; 96 and 97 &plusmn; 3% for FTAI vs. MTAI, respectively). Similar AI conception rates were achieved without estrus detection.</p><br /> <p>Growth and reproductive performance of yearling beef heifers implanted with Revalor G in the Nebraska Sandhills. Crossbred beef heifers (n = 3,242), approximately 12 mo of age, were managed at 3 locationsin the Nebraska Sandhills and randomly assigned to be implanted with Revalor G (40 mg of trenbolone acetate and 8 mg estradiol, IMP), whereas the control (CON) did not receive an implant. Heifers (238 &plusmn; 2 kg) grazed native Sandhills range for the duration of the trial (164 &plusmn; 4 d). Eighty-two &plusmn; 2 d following trial initiation, heifers were synchronized for estrus and AI followed with clean-up bulls as part of a 25 d breeding season. Body weight was measured at the beginning and end of trial. Pregnancy detection occurred 45 d following bull removal at the conclusion of the summer grazing period. Implanted heifers gained more and were heavier (P &lt; 0. 05; 0. 68 vs. 0. 64 &plusmn; 0. 01 kg/d and 347 vs. 340 &plusmn; 3 kg, IMP vs. CON, respectively) at the end of the trial. In contrast, pregnancy rate was greater (P &lt; 0. 01) for CON vs. IMP (64 vs. 46 &plusmn; 3%, respectively). Implanted heifers also had a lower pregnancy rate in their second breeding season (P = 0. 02; 93 vs. 96 &plusmn; 2%, IMP vs. CON, respectively). Implanting beef heifers with Revalor G at approximately 12 mo of age increased ADG and summer BW gain; however, it decreased initial and subsequent pregnancy rate compared with heifers not implanted.</p><br /> <p>Impact of heifer development system on subsequent ADG and reproduction in two different breeding seasons. A 4-yr study was conducted to determine the impact of heifer development system on subsequent growth and reproductive performance in 2 breeding seasons. In Exp. 1, March born, crossbred (5/8 Red Angus, 3/8 Continental; n = 225) heifers were stratified by BW and randomly assigned to of 2 post-weaning nutritional treatments (2 pasture-treatment&middot;yr) from mid-January to mid-April. Heifers were offered ad libitum meadow hay (HAY) and 1. 81 kg/d (29% CP, DM) Supplement or allowed to graze meadow (MDW) and offered 0. 45 kg/d Supplement. Heifers were managed as a single herd before and following treatment. Heifers were synchronized with a single PG injection 5 d after being placed with bulls for a 45 d breeding season. HAY heifers had greater (P = 0. 01) ADG during the treatment period than MDW heifers (0. 77 vs. 0. 51 &plusmn; 0. 03 kg/d; HAY, MDW). At pregnancy diagnosis, HAY heifers tended to have greater BW compared with MDW heifers (P = 0. 06; 377 vs. 367 &plusmn; 3 kg; HAY, MDW). Percent of mature BW before the breeding season was greater (P = 0. 02) for HAY compared with MDW (58% vs. 55% &plusmn; 1%; HAY, MDW). Pregnancy rates were similar for HAY and MDW heifers (P = 0. 97, 88 &plusmn; 4%). In Exp. 2, May-born, crossbred (5/8 Red Angus, 3/8 Continental; n = 258) heifers were stratified by BW and randomly assigned to HAY or MDW treatments. Similar to Exp. 1, heifers on HAY treatment had greater (P = 0. 01) ADG during the treatment period (0. 63 vs. 0. 39 &plusmn; 0. 03 kg/d; HAY, MDW), resulting in greater prebreeding BW (P = 0. 02) for HAY heifers compared with MDW heifers (320 vs. 305 &plusmn; 3 kg, respectively). At pregnancy diagnosis, BW was similar (P = 0. 16) between treatments (368 vs. 356 &plusmn; 4 kg; HAY, MDW). Percent of mature BW before the breeding season was greater (P = 0. 02) for HAY (58%) compared with MDW (54%). Pregnancy rates were similar (P = 0. 44) between treatments (72 vs. 68 &plusmn; 4%; HAY, MDW). Heifer development system did not impact pregnancy rate in the March or May replacement heifers; however, March heifer pregnancy rate was greater (P &lt; 0. 01) than May (87 vs. 70 &plusmn; 3%). The lower pregnancy rate in May heifers may be due to declining forage quality during the breeding season.<br />Effect of postweaning heifer development system on average daily gain, pregnancy rates, and subsequent feed efficiency as a pregnant heifer. A 4-yr study was conducted using Angus-based, spring born heifers. In yr 1, weaned heifers grazed corn residue (CR, n = 50) or were fed in a dry lot (DLHI, n = 50). In yr 2, 3, and 4, heifers grazed CR (n = 75), upland range (RANGE, n = 75), or were fed diets differing in energy, high (DLHI, n = 75) or low (DLLO, n = 75), in a dry lot. Percentage of mature BW before the breeding season was greater (P = 0. 01) for DLHI (67%) compared with Range (59%), CR (60%), and DLLO (63%). Pregnancy rates to AI were similar (P = 0. 39) among treatments (67, 63, 61, 49 &plusmn; 7. 2%; RANGE, CR, DLHI, DLLO), and final pregnancy rates were also similar (84, 90, 91, 91 &plusmn; 5. 4%; Range, CR, DLHI, DLLO; P = 0. 59). A subset of AI pregnant heifers from each treatment was placed in a Calan gate system. Heifers were allowed a 20 d acclimation period before beginning the 90 d trial at approximately gestational d 170. Heifers were offered ad libitum hay; amount offered was recorded daily and orts collected weekly. Initial BW was not different (P = 0. 35) among treatments (451, 457, 472, 464 &plusmn; 10 kg; RANGE, CR, DLHI, DLLO). Body weight at the end of the trial was also similar (P = 0. 24; 488, 497, 511, 502 &plusmn; 14 kg; RANGE, CR, DLHI, DLLO). Intake was similar, either as DMI (P = 0. 27; 9. 74, 9. 97, 10. 18, 10. 00 &plusmn; 0. 76 kg; RANGE, CR, DLHI, DLLO) or residual feed intake (P = 0. 61; 0. 094, 0. 091, &ndash; 0. 056, &ndash;0. 0743 &plusmn; 0. 160 kg; RANGE, CR, DLHI, DLLO). There was no difference in ADG (P = 0. 36; 0. 38, 0. 45, 0. 43, 0. 41 &plusmn; 0. 17 kg/d; RANGE, CR, DLHI, DLLO) among treatments. Although the development cost was not different among treatments (P = 0. 41; $166, 141, 160, 171 &plusmn; 12, RANGE, CR, DLHI, DLLO), there was a $30 numerical difference between the most (DLHI) and least (CR) expensive treatment. Developing heifers to a greater prebreeding BW did not influence subsequent AI or overall pregnancy rates or feed efficiency as a pregnant heifer.</p><br /> <p>North Dakota<br />A technique to ovariohysterectomize cattle for use in gestational research. The time period from conception through the embryonic stage of development is critical in terms of establishment, recognition, and maintenance of pregnancy to term. Research on factors influencing embryonic development up to d 14 is relatively simple. Much less is known about the influences on conceptus (embryo and membranes) development from the time embryo flushing becomes impossible to the end of the embryonic stage (~d 16 to d 50 in bovine). This technique offers a plethora of opportunities to explore factors related to pregnancy success and document embryo and placental development in detail.</p><br /> <p>Before the establishment of trans-placental exchange, nutrients must be transported to the embryo via nutrient transporters. Glucose transporter GLUT3 is known as a greater affinity, facilitated diffusion glucose transporter found in high glucose demanding tissues such as the brain, placenta, sperm, preimplantation embryos and some cancers. The objectives of our current study were 1) develop an immunohistochemistry technique to localize GLUT3 in bovine utero-placental tissues, and 2) confirm the presence and location of GLUT3 in bovine utero-placental tissues. We hypothesized that GLUT3 would be present in utero-placental tissues from d 16 to 50 of gestation. These results accomplished our objectives and clearly supported our hypothesis that GLUT3 is present in uterine tissues from d 16 to 50 of gestation. Further research and more detailed measurements using fluorescence intensity in utero-placental tissues across day and treatments is needed to determine impacts of maternal nutrition status and day of early gestation on localization as well as concentration of the GLUT3 transporter within utero-placental tissues.<br />The objectives of this study were to evaluate the effects of maternal nutrient restriction and day of gestation on mRNA expression of syncytin-Rum1, bovine endogenous retrovirus K1 (BERV-K1), interferon-tau (INF-&tau;), and pregnancy specific protein B (PSP-B). At breeding (0 d), crossbred heifers (n = 49; ~15 mo of age; initial BW = 324. 9 kg) were assigned to dietary treatments, control (fed to gain 0. 45 kg/d BW gain) or restricted (60% of control). Heifers were ovariohysterectomized at d 16, 34, or 50 resulting in a 2 &times; 3 factorial. Our results indicate that both BERV-K1 and syncytin-Rum1 may interact with PSP-B during the establishment of the fetomaternal interface and syncytial plaques.</p><br /> <p>We hypothesized that maternal nutrition and day of gestation would impact mRNA expression of nutrient transporters GLUT1, CAT-1, CAT-2, and CAT-3 in beef heifers. Crossbred Angus heifers (n = 49) were synchronized, bred via AI, assigned to nutritional treatment (CON = 100% of requirements for 0. 45 kg/d gain and RES = 60% of CON) and ovariohysterectomized on d 16, 34, or 50 of gestation (n = 6 to 9/d); non-pregnant (NP) controls were not bred and ovariohysterectomized on d 16 of the synchronized estrous cycle (n = 6). The resulting arrangement of treatments was a 2 &times; 3 factorial + 1. Our results partially support our hypothesis and indicate that day was a more influential factor for mRNA expression of utero-placental glucose and cationic amino acid transporters than maternal nutritional status in heifers during early pregnancy.<br /><br />Oregon<br />Impacts of stocking density on development and puberty attainment of replacement beef heifers. We hypothesized that elevated stocking density impairs welfare and reproductive development in beef heifers. We compared growth, physical activity, stress-related and physiological responses, and puberty attainment in heifers reared on high (dry lots) or low (pastures) stocking densities from weaning until the start of their first breeding season. Rearing replacement beef heifers in dry lots with high stocking density negatively impacted stress-related and physiological responses, and delayed puberty attainment compared with rearing heifers in pastures with low stocking density. Moreover, these outcomes were independent of heifer nutritional status and growth rate, but were associated with reduced physical activity and increased chronic stress caused by high stocking density. Therefore, stocking density should be considered in heifer development programs to optimize reproductive and overall efficiency of cow-calf operations.</p><br /> <p>Effects of vaccination against foot-and-mouth disease (FMD) virus on reproductive performance of Bos indicus beef cows. We hypothesized that administration of a FMD vaccine during early pregnancy stimulates an acute-phase protein reaction and results in increased pregnancy loss in vaccinated cattle. Our objectives were to compare reproductive performance of Bos indicus cows vaccinated against FMD virus before timed-AI or during early pregnancy (Exp. 1), as well as rectal temperature and plasma concentrations of the acute-phase protein haptoglobin in cattle vaccinated or not against the FMD virus (Exp. 2). We concluded that vaccinating B. indicus beef cows against FMD virus resulted in a 4-fold increase in pregnancy loss when the vaccine was administered 30 d after timed-AI compared with 31 d before timed-AI. These outcomes can be associated with inflammatory and acute-phase reactions elicited by the FMD vaccine, which are known to impair pregnancy maintenance in cattle.<br />Expression of estrus modifies the gene expression profile in reproductive tissues on d 19 of gestation in beef cows. We hypothesized that expression of estrus is associated with a complete maturation and function of the preovulatory mechanisms. Our objectives were to test the effects of behavioral expression of estrus before AI on gene expression of target transcripts in the endometrium, CL, and conceptus on Day 19 of gestation. We concluded that estrus expression at the time of AI favorably altered the gene expression profile in reproductive tissues during the preimplantation phase toward a more receptive state to the elongating conceptus. These effects seem to be more evident in the endometrium during the time of dynamic remodeling for embryo implantation.</p><br /> <p>South Dakota<br />Influence of preovulatory estradiol on conceptus survival and uterine glucose transporter expression. Glucose is an essential component of uterine secretions and is delivered into the uterine luminal fluid (ULF) by glucose transporters. We have previously reported increased concentrations of glucose in the ULF of cows that exhibited estrus. Our objective was to determine effects of preovulatory estradiol on abundance of glucose transporters in uterine endometrium. Glucose transporter abundance in the endometrium of beef cows was influenced by preovulatory estradiol and presence of a conceptus. This may serve as a possible mechanism to regulate glucose concentrations into the uterine lumen where it can be utilized by the developing conceptus.<br />Differences in abundance of GnRH-I and GnRH-II among bovine antral follicles. Estradiol plays a critical role in fertility among cattle, specifically it has been reported that preovulatory estradiol regulates uterine pH, sperm transport, and uterine secretions that impact embryo development and survival. Both GnRH and GnRH receptors have been reported in granulosa cells of cattle, and among other species GnRH has been reported to modulate follicular steroidogenesis. Thus, the objective of the current study was to determine changes in the relative abundance of GnRH-I and GnRH-II mRNA within granulosa cells of bovine follicles. Thus, decreased abundance of GnRH-I and GnRH-II mRNA may play a role in increased production of estradiol. USDA is an equal opportunity provider and employer.<br /><br />US-MARC-Nebraska<br />Mechanisms of improved reproductive function in heifers with increased numbers of antral follicles. Heifers with increased numbers of antral follicles detectable by ultrasonography conceive earlier in their first breeding season. To investigate whether this is due to improved uterine function or improved oocyte quality, a four year study was initiated. Angus heifers (120/yr) were submitted for ultrasonographic examination to determine antral follicle number at 325 d of age and 355 d of age. Each year, the 10 pubertal heifers with the greatest average number of antral follicles and the 10 heifers with the lowest average number of antral follicles were synchronized with two i.m. shots of Lutalyse administered 11 d apart, and reproductive tracts were harvested on d 6 or d 16 after behavioral estrus. Uterine weights were greater for heifers with increased numbers of antral follicles compared with heifers with diminished numbers of antral follicles (P &lt; 0. 01). Uterine protein concentrations were greater in heifers with greater numbers of antral follicles (P &lt; 0. 01). Oocytes were aspirated from follicles (&lt; 7 mm) and used for in vitro embryo production. No difference was detected in the percentage of oocytes that cleaved; however, a greater (P &lt; 0. 01) percentage of oocytes from High AFC heifers developed to the blastocyst stage compared with oocytes from Low AFC heifers.<br />Ovarian phenotype and function differ in Bos indicus cows and may contribute to differences in reproductive capacity. Past research has demonstrated that antral follicle numbers are increased in Bos indicus cattle, but there is no corresponding increase in fertility. In fact, uterine protein concentrations are lower in Bos indicus cattle. In addition, several studies have indicated no difference in primordial follicle numbers in Bos indicus ovaries; however, Bos indicus ovaries are larger. Bos taurus heifers with diminished numbers of primordial follicles have smaller ovaries with fewer primordial follicles per gram of ovarian tissue, and decreased uterine protein concentrations. Therefore, we hypothesized that Bos indicus cows would have fewer primordial follicles per gram of ovarian tissue. From our results, differences exist in the ovarian function in Bos indicus that may contribute to differences in fertility and reproductive longevity.</p><br /> <p>Genetic marker effects and type of inheritance are estimated with poor precision when minor marker allele frequencies are low. An Angus population was subjected to marker assisted selection for multiple years to equalize CAPN1 haplotypes, CAST, and GHR genetic marker frequencies. The objective was to estimate the pleiotropic effects of these carcass quality oriented markers for BW, reproduction, and first calf performance traits in replacement beef females (n = 174) which were managed under 2 post-weaning development protocols. This study characterizes an important genetic effect for maternal heterosis advantages in expected maintenance requirements and highlights the importance of understanding genetic marker pleiotropy when incorporating genetic markers into selection decisions.</p><br /> <p>Virginia<br />Maturation of bovine cumulus-oocyte complexes with follicle fluid varying in estradiol content affects cumulus cell expansion without affecting subsequent embryo development in vitro. The objective of this work was to determine how characteristics of bovine follicle fluid (FF; especially estradiol content) affect cumulus cell expansion and oocyte competence. Results of our studies indicate that although FF improves cumulus cell expansion during maturation in vitro, it does not result in greater rates of cleavage or blastocyst development regardless of estradiol content.</p><br /> <p>Effects of administration of ovulation induction factor on CL volume, concentration of progesterone (P4), and conceptus development. The objective of this study was to determine if systemic administration of ovulation induction factor (OIF), also known as nerve growth factor beta (NGF), to cows at the time of artificial insemination would affect CL volume, concentration of P4, and conceptus development. A total of 60 suckled beef cows were synchronized using a 7 d CO-Synch + CIDR protocol and were randomly assigned to one of two treatments at the time of insemination: i.m. injection of 5 mL of saline (CON; n = 30); or intramuscular injection of 5 mL (250 &mu;g) of purified NGF (NGF; n =30). Treatment of cows with NGF at timed AI did not affect CL volume, but increased concentration of P4.</p><br /> <p>Objective 2. To increase the efficiency and predictability of sustainable reproductive management programs for cattle.</p><br /> <p>Florida<br />Presynchronization with PGF2 7-d before initiation of the 7-d CO-Synch+CIDR protocol alters estrus expression, but fails to enhance pregnancy rates to TAI.</p><br /> <p>Use of a high concentrate, subcutaneous dose of PGF2 compared with a conventional 25 mg dose of PGF2 does not alter estrus response or pregnancy rates in replacement beef heifers exposed to the 7-d CIDR + CO-Synch protocol.</p><br /> <p>Use of estrus synchronization and timed AI in Bos indicus beef heifers increased the percentage of heifers pregnant early in the breeding season compared with heifers not exposed to estrus synchronization and TAI.<br />Administration of bST before artificial insemination increased IGF1 at fixed-time AI (TAI), but failed to increase fetal growth and decreased pregnancy rates to TAI.</p><br /> <p>Bos taurus recipients exposed to an energy and protein restriction during early gestation experienced greater embryonic loss compared with Bos indicus influenced cows.</p><br /> <p>Bos taurus embryos had greater embryonic loss when the dam underwent feed restriction during early gestation.<br />Iowa</p><br /> <p>GnRH administration may not be needed at the initiation of the 5-d CO-Synch + CIDR ovulation synchronization program to achieve acceptable timed-artificial insemination pregnancy rates. A greater proportion of Angus heifers that were desirable for both average daily gain (above average) and residual feed intake (below average) during their yearling feed efficiency test remained in the herd at 3 and 4 yr of age compared with all other contemporaries.</p><br /> <p>Quantification of varying trace mineral concentrations in spermatozoa, seminal plasma, and whole semen samples indicate that semen may be a viable biomarker for trace mineral status.</p><br /> <p>&nbsp;</p><br /> <p>Kansas<br />Using an activity monitoring system (AMS) equipped with an accelerometer, 2 experiments were conducted to test the hypotheses that: (1) enhancing P4 before inducing luteolysis or (2) exposing cows to estradiol cypionate (ECP) or testosterone propionate (TP) after luteolysis would increase occurrence and intensity of estrus. Only ECP was successful in inducing more expression and intensity of estrus, but proportions of cows detected in estrus barely exceeded 80%. Given the large proportion of cows equipped with AMS collars ovulating in the absence of estrus, further research is warranted to determine if more pregnancies can be achieved by inseminating those cows not detected in estrus at an appropriate time after PGF2&alpha;-induced luteolysis.<br />Gonadotropin-releasing hormone increased pregnancy risk in suckled beef cows not detected in estrus and subjected to a split-time artificial insemination program. We hypothesized that GnRH would increase pregnancy risk in a split-time AI program for cows in which estrus was not detected. A total of 1,236 suckled beef cows at 12 locations in 3 states (CO, KS, and ND) were enrolled. Before applying the fixed-time AI program, BCS was assessed. Cows were treated on d &ndash;7 with a P4 insert concurrent with 100 &mu;g GnRH and on d 0 with 25 mg PGF2&alpha; plus removal of the insert. Cows had greater PR when they had been detected in estrus before AI, and PR was improved by administration of GnRH at 65 h after insert removal in cows that were not detected in estrus and inseminated at 84 h. The split-time AI program serves as a compromise between conventional AI after detection of estrus and a standard one-fixed time AI program. Depending on the cost of GnRH (range of $2.22 to $3.10 per dose) and 60% of cows in estrus by 65 h, the economic trade-off of using estrus-detection patches in a split-time AI program is favorable and saved $0.33 to $0.86 per cow, but does not account for the extra time and cow-calf handling invested to carry-out the second AI at 84 h. Furthermore, cost of semen and sire selection for cows detected in estrus having resulting greater pregnancy risk compared with those not detected in estrus having lesser pregnancy risk, could provide other favorable options and economic advantages for employing a split-time AI program.</p><br /> <p>Mississippi<br />Characteristics of ovulatory and non-ovulatory dominant follicles among beef cows exhibiting two and three follicular waves. During an estrus synchronization and timed artificial insemination (TAI) protocol in cattle, ovulation of the dominant follicle of any wave is possible depending on what day of the estrous cycle the protocol is initiated. The first follicular wave emerges around the time of ovulation when the circulating concentration of P4 is low but increasing, whereas the second follicular wave emerges during diestrus when the circulating concentration of P4 is greatest. The primary objective of this study was to characterize intra-follicular concentrations of E2 and P4 in dominant follicles of each wave in females exhibiting 2 or 3 waves of follicular development. Ovulatory follicles contained greater concentrations of E2 than non-ovulatory follicles after 4 d of dominance; however, when comparing non-ovulatory follicles from females exhibiting 2 or 3 waves and comparing ovulatory follicles from females exhibiting 2 or 3 waves, concentrations of steroid hormones were similar. In addition, concentrations of steroid hormones in follicular fluid did not differ between females classified as low antral follicle count or moderate antral follicle count. Blood perfusion of the dominant follicle tended to be greater in dominant follicles from the second nonovulatory wave in females exhibiting 3 waves. Diameters of dominant follicles of the second non-ovulatory wave in females exhibiting 3 waves were smallest in diameter and no differences in diameter were observed among dominant follicles from other waves.<br />The dominant follicle of the first follicular wave (FFW) develops when the concentration of P4 is increasing whereas the dominant follicle of the second follicular wave (SFW) develops under maximal concentrations of P4. We hypothesized that females synchronized to ovulate the dominant follicle of the SFW at AI would have improved fertility characteristics compared with females synchronized to ovulate the dominant follicle of the FFW. The objectives of this experiment were to determine the effects of follicular wave (first or second) on diameter of the dominant follicle, concentrations of P4 and estradiol and the hepatic enzymes that inactivate them, thickness of the endometrium, as well as pregnancy rates to AI. Cows inseminated to the FFW had an increased diameter of the dominant follicle compared with cows inseminated to the SFW. Treatment did not impact the thickness of the endometrium. Concentrations of P4 were greater and concentrations of estradiol tended to be lesser in females assigned to the SFW, although of the liver enzymes measured, only concentrations of CYP1A differed between treatments. When considering all females and only those that were effectively presynchronized, pregnancy rates were similar between treatments. When evaluating females that ovulated to the assigned follicular wave, heifers in the SFW had greater pregnancy rates than heifers in the FFW, whereas pregnancy rates in cows did not differ among treatments, and this interaction warrants further evaluation.</p><br /> <p>Missouri<br />This experiment was designed to evaluate split-time artificial insemination (STAI) in beef heifers following administration of the 14-d controlled internal drug release (CIDR)-prostaglandin F2&alpha; (PG) protocol and to compare pregnancy rates among non-estrous heifers based on administration of GnRH at AI. Estrus was synchronized for 1,138 heifers across 6 locations. When split-time AI was used in conjunction with the 14-d CIDR-PG protocol in heifers, comparable pregnancy rates were achieved without administering GnRH.</p><br /> <p>This experiment was designed to compare pregnancy rates in postpartum beef cows following split-time (STAI) or fixed-time (FTAI) artificial insemination. Estrus was synchronized for 671 cows at 7 locations following administration of the 7-d CO-Synch + CIDR protocol (100 &mu;g GnRH + CIDR insert [1. 38 g P4] on d 0; 25 mg prostaglandin F2&alpha; [PG] at CIDR removal on d 7). In summary, following administration of the 7-d CO-Synch + CIDR protocol, total estrous response increased and pregnancy rates resulting from AI tended to be greater among cows assigned to STAI versus FTAI treatments.</p><br /> <p>This experiment was designed to compare the 14-d CIDR-PG (14-d) and 7-d CO-Synch + CIDR (7-d) protocols on the basis of estrous response, pregnancy rates resulting from fixed-time AI (FTAI), and final pregnancy rates at the end of the breeding season in primiparous 2-yr-old beef cows. Our results indicated that the 14-d CIDR-PG and 7-d CO-Synch + CIDR protocols may be used to effectively synchronize estrus before FTAI in primiparous 2-yr-old beef cows.</p><br /> <p>Another experiment was designed to test the hypothesis that estrous response and pregnancy rate following synchronization of estrus with the 14-d CIDR-PG protocol in primiparous 2-yr-old beef cows would be improved using split-time AI (STAI) compared with fixed-time AI (FTAI). Estrus was synchronized for 523 primiparous, postpartum beef cows at 5 locations. Estrus expression was increased when STAI was used following synchronization of estrus with the 14-d CIDR-PG protocol in primiparous 2-yr-old beef cows; however, this strategy did not result in significant improvements in AI pregnancy rates compared with FTAI.<br />Although the 14-d CIDR-PGF2 (PG) protocol can be effectively used in mature cows with either a 16- or 19-d interval from CIDR removal to PG, producers may be reluctant to adopt this protocol because: (1) the duration of the treatment schedule; and (2) low estrus-response rates by the time of FTAI at 72 h after PG. To address these considerations, Thomas et al. (2016a) evaluated a modified presynchronization approach in which PG was administered at CIDR insertion. Inducing luteolysis among responsive cows in this manner facilitated a shortened duration of progestin treatment from 14 to 9 d while achieving similar size dominant follicles at CIDR removal. To account for cows whose CL may not have responded to the PG administered at CIDR insertion (e. g., cows who had ovulated &lt; 5 d before CIDR insertion), PG is administered again to all cows at CIDR removal in the 9-d CIDR-PG protocol. As in the standard 14-d CIDR-PG protocol, PG is administered 16 d after CIDR removal. Preliminary results (Thomas et al., 2016a) indicated a tendency for increased estrus-response rate after CIDR removal following the 9-d CIDR-PG treatment schedule compared with the 14-d CIDR-PG. In addition, estrous response after PG was significantly greater among 9-d CIDR-PG treated cows, and synchrony of estrus expression was noteworthy. Split-time AI was conducted, with cows having expressed estrus receiving timed AI at 72 h after PG, and cows not expressing estrus by 72 h receiving timed AI 24 h later at 96 h. In this pilot study, greater pregnancy rates were observed for 9-d CIDR-PG treated cows (77%; 33/43) compared with 14-d CIDR-PG treated cows (60%; 25/42). A subsequent field trial with larger numbers evaluated the 9-d CIDR-PG versus 14-d CIDR-PG protocols on the basis of pregnancy rate to FTAI performed at 72 h after PG. Greater pregnancy rates were again obtained by cows treated with the 9-d CIDR-PG protocol (63%; 100/158) compared with cows treated with the 14-d CIDR-PG protocol (53%; 86/163).</p><br /> <p>Two long-term, CIDR-based estrus-synchronization protocols were evaluated among Bos indicus-influenced and Bos taurus beef heifers. Treatments were evaluated on the basis of estrous response and pregnancy rate resulting from fixed-time artificial insemination, and these outcomes were analyzed retrospectively relative to reproductive tract score at treatment initiation. The long-term CIDR-based protocols provide a simple, effective method of estrus synchronization in Bos indicus-influenced and Bos taurus beef heifers. Moreover, these results highlight the importance of management practices that result in high rates of estrous cyclicity before protocol initiation, particularly among later maturing breeds and biological types.</p><br /> <p>North Dakota<br />Effects of breeding system of origin (natural service or artificial insemination) on pregnancy rates, distribution of calving, and calf weaning weights of commercial beef cow herds in North Dakota. Objectives of this study were to compare pregnancy rates, calving distribution, and calf weaning weights of commercial beef cows exposed to two different breeding systems. Producers recruited (n = 10) had never implemented estrus synchronization and AI into their reproductive management plan. Use of timed AI in commercial beef herds increased the number of calves born earlier in the calving season and increased the weaning weights of calves.</p><br /> <p>Effects of pre-breeding administration of injectable trace mineral supplements on subsequent reproductive performance in beef herds. Commercial beef cows (n = 1,311) originating from 4 herds in North Dakota were stratified within herd by days postpartum, then randomly assigned to receive either of 2 treatments: 1) cows received no additional treatments before bull turnout (CON; n = 638); or 2) cows were administered an injectable trace mineral supplementation (60, 10, and 15 mg/mL of zinc, manganese and copper as disodium EDTA chelates, and 5 mg/mL selenium as sodium selenite) subcutaneously on d 30 relative to bull turnout (TM; n = 673). When evaluating the distribution of calves born in the calving season by 21-d increments, the proportion of calves born in the first 21, 22 to 42, or more than 42 d of the calving season were similar (P = 0.40) between treatments.</p><br /> <p>Evaluating results of pre-breeding reproductive examinations in yearling and mature beef bulls via the BullTest data reporting system. Over a 2-yr period data were collected to summarize incidence and reasons for failure of reproductive soundness examinations in yearling and mature beef bulls. Upon completion of examinations, participating veterinarians completed the BullTest card by indicating the number of yearling and mature bulls evaluated and the number of bulls in each age class that failed the examination. Examination failures were further classified by indicating number of bulls failing for each of the following reasons: semen motility, semen morphology, excess white blood cells present in ejaculate, penile injury/defects, wart proliferation, feet and leg conformation, scrotal circumference, and &ldquo;other&rdquo;. In addition, practitioners indicated the type of examination conducted; simple semen exam or full breeding soundness exam (BSE), whether the test was for a breeding herd or production sale, and whether the test was the initial evaluation of bulls or a retest. The BullTest system provided an excellent platform to summarize results of pre-breeding reproductive evaluations in beef bulls.</p><br /> <p>Oregon<br />Effects of post-AI supplementation with Ca salts of soybean oil (CSSO) on pregnancy establishment parameters in Bos indicus beef cows. We hypothesized that CSSO supplementation during early gestation favors maternal and embryonic responses required for pregnancy establishment, including PGE2 synthesis and the IFNt-signaling cascade. Our objectives were to investigate the effects of CSSO Supplementation during early gestation on hormonal, uterine, and conceptus parameters associated with pregnancy establishment in B. indicus beef cows. We concluded that post-AI CSSO supplementation to beef cows increased plasma concentration of linoleic acid and enhanced pregnancy establishment variables, which includes CL development and plasma P4 concentrations, conceptus growth and mRNA expression of interferon-tau, as well as blood mRNA expression of interferon-stimulated genes.</p><br /> <p>Impacts of meloxicam before temporary calf weaning on physiological and reproductive responses of Bos indicus beef cows. We hypothesized that meloxicam administration to beef cows mitigates inflammatory reactions induced by temporary calf weaning (TCW) and further improves pregnancy rates to timed AI.<br /><br />Our objectives were to evaluate temperament, physiological, and reproductive variables in B. indicus beef cows assigned to an estrus synchronization + timed-AI protocol including eCG administration, TCW, or TCW + meloxicam administration. We concluded that TCW during estrus synchronization did not impact temperament or serum haptoglobin concentrations in B. indicus beef cows, but increased serum cortisol concentrations compared with cows not assigned to TCW, although such outcome was not sufficient to impact pregnancy rates to timed-AI. Moreover, administration of meloxicam did not alleviate the TCW-induced increase in serum cortisol concentrations, and failed to benefit pregnancy rates to timed AI in B. indicus beef cows.<br />Creep-feeding to stimulate metabolic imprinting in nursing beef heifers: Impacts on heifer growth, reproductive, and physiological parameters. We hypothesized that management to stimulate metabolic imprinting, such as creep-feeding, may accelerate puberty in heifers by enhancing nutrient utilization and lipogenesis. Our objectives were to compare growth, reproductive, and physiological responses of beef heifers with or without access to a creep-feeder while nursing their dams, as a manner to stimulate metabolic imprinting. We concluded that supplementing nursing heifers via creep-feeding for 50 d altered physiological and biochemical variables suggestive of a metabolic imprinting effect, but did not hasten their puberty attainment.<br />Effects of protein supplementation frequency on physiological responses associated with reproduction in beef cows. We hypothesized that beef cows supplemented with protein infrequently would have reduced uterine pH and circulating P4 concentrations following a supplementation event. Our objectives were to determine the effects of protein supplementation frequency on physiological responses and hepatic expression of genes associated with metabolism and reproductive function of beef cows. We concluded that decreasing frequency of protein supplementation did not reduce uterine flushing pH or plasma P4 concentrations, which are known to impact reproduction in beef cows.</p><br /> <p>South Dakota<br />The role of preovulatory estradiol in maternal recognition of pregnancy and embryonic survival has not been well established among beef cows. Our objective was to determine the effects of preovulatory estradiol on regulating the uterine environment from fertilization to maternal recognition of pregnancy. Embryo recovery rates and uterine flush protein content did not differ between cows that did or did not exhibit estrus, but uterine flush glucose content was greater in cows that exhibited estrus. There was no difference in uterine flush glucose content between cows that did and did not have an embryo, but uterine flush protein content was greater in cows from which an embryo was recovered.</p><br /> <p>Wisconsin<br />Treatment with 12.5 mg of PGF2&alpha; 5 d after induction of ovulation temporarily decreased P4 concentrations from 6 to 11 d after timed AI without inducing luteal regression. Decreasing P4 after decreased expression of ISG15 in blood leukocytes 20 d after timed AI, serum PSPB concentrations 25 to 67 d after, and embryo size 46 d after timed AI but did not affect pregnancy per AI (P/AI) in lactating Holstein cows.</p><br /> <p>Addition of a second PGF2&alpha; (dinoprost) treatment during a Resynch protocol tended to increase P/AI to timed AI by increasing the percentage of cows with complete luteal regression at GnRH-2, whereas doubling the dose of PGF2&alpha; did not.<br />Synchronization of ovulation and timed AI for first service increased the percentage of cows inseminated within 7 d after the VWP, and timed AI cows had greater fertility at first service than cows inseminated after estrus at a similar DIM range.</p>

Publications

<p>Publications<br />Peer-reviewed Journals</p><br /> <p>Abel, J. M., B. E. Bishop, J. M. Thomas, M. R. Ellersieck, S. E. Poock, M. F. Smith, and D. J. Patterson. 2016. Comparing strategies to synchronize estrus and ovulation before fixed-time artificial insemination in primiparous two-year-old beef cows. Theriogenology. (Submitted).</p><br /> <p>Al Naib, A., H. L. Tucker, G. Xie, D. H. Keisler, F. F. Bartol, R. P. Rhoads, R. M. Akers and M. L. Rhoads. 2016. Prepubertal tamoxifen treatment affects development of heifer reproductive tissues and related signaling pathways. J. Dairy Sci. 99:5780-5792.</p><br /> <p>Amundson, O. L. E. L. Larimore, A. K. McNeel, C. C. Chase, Jr., R. A. Cushman, H. C. Freetly, and G. A. Perry. 2016. Uterine environment and pregnancy rate of heifers fed different levels of protein. Anim. Reprod. Sci. (R1 Submitted).</p><br /> <p>Amundson, O. L. T. G. Fountain, E. L. Larimore, B. N. Richardson, A. K. McNeel, E. C. Wright, D. H. Keisler, R. A. Cushman, G. A. Perry, H. C. Freetly. 2015. Post-weaning nutritional programming of ovarian development in beef heifers. J. Anim. Sci. 93:5232-5239.</p><br /> <p>Anderson, J. L., K. F. Kalscheur, J. A. Clapper, G. A. Perry, D. H. Keisler, A. D. Garcia, and D. J. Schingoethe. 2015. Feeding fat from distillers dried grains with solubles to dairy heifers: metabolic profile. J. Dairy Sci. 98:5709-5719.</p><br /> <p>Bishop, B. E., J. M. Thomas, J. M. Abel, S. E. Poock, M. R. Ellersieck, M. F. Smith, and D. J. Patterson. 2016. Split-time artificial insemination in beef cattle: I. Using estrous response to determine optimal time(s) at which to administer GnRH in beef heifers and postpartum cows. Theriogenology 86: 1102-1110.</p><br /> <p>Bishop, B. E., J. M. Thomas, J. M. Abel, S. E. Poock, M. R. Ellersieck, M. F. Smith, and D. J. Patterson. 2016. Split-time artificial insemination in beef cattle. II. Comparing pregnancy rates among non-estrous heifers based on administration of GnRH at AI. Theriogenology. In press.</p><br /> <p>Bolzenius, J. K., R. A. Cushman, and G. A. Perry. 2016. Expression of Na+/H+ exchanger isoforms 1, 2, 3, and 4 in bovine endometrium and the influence of uterine pH at fixed-timed AI of pregnancy success. Anim. Reprod. Sci. 171:98-107.</p><br /> <p>Brown, B. M., J. W. Stallings, J. S. Clay and M. L. Rhoads. 2015. Periconceptional heat stress of Holstein dams is associated with differences in daughter milk production and composition during multiple lactations. PLOS ONE. 10: e0133574.</p><br /> <p>Brown, B. M., J. W. Stallings, J. S. Clay and M. L. Rhoads. 2016. Periconceptional heat stress of Holstein dams is associated with differences in daughter milk production during their first lactation. PLOS ONE. 11:e0148234.</p><br /> <p>Cappellozza, B. I., R. F. Cooke, M. M. Reis, R. S. Marques, T. A. Guarnieri Filho, G. A. Perry, D. B. Jump, K. A. Lytle, and D. W. Bohnert. 2015. Effects of protein Supplementation frequency on physiological responses associated with reproduction in beef cows. J. Anim. Sci. 93:386-394.</p><br /> <p>Cerny, K. L., L. Anderson, W. R. Burris, M. Rhoads, J. C. Matthews and P. J. Bridges. 2016. Form of Supplemental selenium fed to cycling cows affects systemic concentrations of progesterone but not those of estradiol. Theriogenology 85:800-806.</p><br /> <p>Cipriano, R. S. M. C. V. Miguel, M. A. Maioli, L. M. Pavanello, D. Giraldo-Arana, R. F. Cooke, M. L. Day, and G. P. Nogueira. 2015. Follicular profile, LH and leptin concentrations in prepubertal Nellore heifers treated with fat acids or high energy. Braz. J. Vet. Res. (In press).</p><br /> <p>Cipriano, R. S., R. F. Cooke, A. D. Rodrigues, L. G. T. Silva, D. W. Bohnert, R. S. Marques, J. L. M. Vasconcelos, A. V. Pires, and R. L. A. Cerri. 2016. Effects of post-AI Supplementation with Ca salts of soybean oil on pregnancy establishment parameters in Bos indicus beef cows. J. Anim. Sci. (In review).</p><br /> <p>Cline, G. F., A. M. Muth-Spurlock, B. E. Voelz, C. O. Lemley, and J. E. Larson. 2016. Evaluating blood perfusion of the corpus luteum in beef cows during fescue toxicosis. J. Anim. Sci. 94:90-95.</p><br /> <p>Cooke, R. F., R. F. G. Peres, R. S. Cipriano, T. A. Guarnieri Filho, R. S. Marques, M. C. Rodrigues, R. S. Carvalho, D. W. Bohnert, and J. L. M. Vasconcelos. 2016. Impacts of meloxicam before temporary calf weaning on physiological and reproductive responses of Bos indicus beef cows. J. Anim. Sci. 94:406-411.</p><br /> <p>Crouse, M. S., J. S. Caton, K. J. McLean, P. P. Borowicz, L. P . Reynolds, C. R. Dahlen, B. W. Neville, and A. K. Ward. 2016. Rapid Communication: Isolation of glucose transporters GLUT3 and GLUT14 in bovine utero-placental tissues from d 16 to 50 of gestation. doi: 10. 2527/jas. 2016-0808; Date posted: August 12, 2016</p><br /> <p>da Silva, A. G., D. C. Adams, and R. N. Funston. 2016. Fall-breeding beef females failing to conceive during spring breeding. Prof. Anim. Sci. 32:243-247.</p><br /> <p>Daetz, R., F. Cunha, J. H. Bittar, C. A. Risco, F. Magalhaes, Y. Maeda, J. E. P. Santos, K. C. Jeong, R. F. Cooke, and K. N. Galv&atilde;o. 2016. Safety of chitosan microparticles administration and efficacy in preventing metritis in lactating dairy cows. J. Dairy Sci. 10. 3168/jds. 2016-11400.</p><br /> <p>Dahlen, Carl R. and Charles L. Stoltenow. 2015. The PregCard study; assessing the impact of routine management strategies on reproductive performance of beef herds in the upper Great Plains. Bov. Pract. 49:152-155.</p><br /> <p>Davoodi, S., R. F. Cooke, A. C. C. Fernandes, B. I. Cappellozza, J. L. M. Vasconcelos, and R. L. A. Cerri. 2015. Expression of estrus modifies the gene expression profile in reproductive tissues on day 19 of gestation in beef cows. Theriogenology 85:645-655.</p><br /> <p>Deaver, S. E., A. M. Felix and M. L. Rhoads. 2015. Reproductive performance of lactating dairy cattle after intrauterine administration of a prostaglandin F2&alpha; receptor antagonist four days after insemination. Theriogenology 83:560-566.</p><br /> <p>Dohlman, T. M., D. M. Madson, P. E. Phillips, C. A. Clark, and P. J. Gunn. 2016. Effects of label-dose permethrin administration in yearling beef cattle: II. Bull reproductive function and testicular histopathology. Theriogenology 85:1534-1539.</p><br /> <p>Dohlman, T. M., M. M. Jahnke, J. K. West, P. E. Phillips, and P. J. Gunn. 2016. Effects of label-dose permethrin administration in yearling beef cattle: I. Reproductive function and embryo quality of superovulated heifers. Theriogenology 85:1528-1533.</p><br /> <p>Ferreira, L. C. L., R. F. Cooke, R. S. Marques, H. J. Fernandes, C. E. Fernandes, R. Stelato, G. L. Franco, and R. A. A. Lemos. 2016. Effects of vaccination against foot-and-mouth disease virus on reproductive performance of Bos indicus beef cows. J. Anim. Sci. 94:401-405.</p><br /> <p>Fricke, P. M., P. D. Carvalho, M. C. Lucy, F. Curran, M. M. Herlihy, S. M. Waters, J. A. Larkin, M. A. Crowe, and S. T. Butler. 2016. Effect of manipulating progesterone before timed artificial insemination on reproductive and endocrine parameters in seasonal‐calving pasture‐based Holstein‐Friesian cows. J. Dairy Sci. 99:6780‐6792.</p><br /> <p>Funston, R. N., E. E. Grings, A. J. Roberts, and B. T. Tibbitts. 2016. Choosing a calving date. Prof. Anim. Sci. 32:145-153.</p><br /> <p>Gaievski, F. R., G. C. Lamb, R. R. Weiss, M. A. F. Bertol, M. S. Sequi, A. C. M. R. Abreu, L. E. Kozicki. 2015. Gonadotropin releasing hormone (GnRH) and equine chorionic gonadotropin (eCG) improve the pregnancy rate on protocols for timed-artificial insemination in beef cattle. Vet. E. Zootech. 22:471-480.</p><br /> <p>Geppert, T. C. A. M. Meyer, G. A. Perry, and P. J. Gunn. 2016. Effects of excess dietary metabolizable protein from corn gluten meal or soybean meal on ovarian function and circulating amino acid concentrations of beef cows consuming low quality forage. Animal (In Press)</p><br /> <p>Geppert, T. C. A. M. Meyer, G. A. Perry, and P. J. Gunn. 2016. Effects of supplementing excess amounts of metabolizable protein from a moderately abundant rumen undegradable source on ovarian function and circulating amino acid concentrations of beef cows consuming low quality forage. Animal (In Press)</p><br /> <p>Geppert, T. C., A. M. Meyer, G. A. Perry, and P. J. Gunn. 2016. Effects of excess metabolizable protein on ovarian function and circulating amino acids of beef cows: 1. Excessive Supply from corn gluten meal or soybean meal. Animal (Accepted).</p><br /> <p>Grazul-Bilska, A., C. S. Bass, S. L Kaminski, G. A. Perry, and D. A Redmer. 2015. Progesterone secretion by ovine granulosa cells: effects of nitric oxide and plane of nutrition. Can. J. Phys. Pharm. 93:973-978.</p><br /> <p>Gunn, P. 2016. Optimizaci&oacute;n de la nutrici&oacute;n de ganado de carne de concepci&oacute;n hasta consumo. Ceiba. 54:14-22.</p><br /> <p>Gunn, P. J., R. P. Lemenager, K. C. Culp, and G. A. Bridges. 2016. Efficacy of the 5 day CO-Synch estrous synchronization protocol with or without the inclusion of a CIDR in beef cows. Prof. Anim. Sci. 32:82-89.</p><br /> <p>Hill, S. L., D. M. Grieger, K. C. Olson, J. R. Jaeger, C. R. Dahlen, G. A. Bridges, F. Dantas, J. E. Larson, A. M. Muth-Spurlock, J. K. Ahola, M. C. Fischer, G. A. Perry, E. L. Larimore, T. L. Steckler, W. D. Whittier, J. F. Currin, and J. S. Stevenson. 2016. Using estrus-detection patches to optimally time insemination improved pregnancy risk in suckled beef cows enrolled in a fixed-time artificial insemination program. J. Anim. Sci. 94:doi: 10. 2527/jas. 2016-0469; Published: June 14, 2016.</p><br /> <p>Hill, S. L., D. M. Grieger, K. C. Olson, J. R. Jaeger, C. R. Dahlen, M. R. Crosswhite, N. Negrin Pereira, S. R. Underdahl, B. W. Neville, J. Ahola, M. C. Fischer, G. E. Seidel, and J. S. Stevenson. 2016. GnRH increased pregnancy risk in suckled beef cows not detected in estrus and subjected to a split-time artificial insemination program. J. Anim. Sci. 94:doi:10. 2527/jas. 2016-0582, Published: August 11, 2016.</p><br /> <p>Kramer, R. W., D. R. Smith, G. R. Rupp, D. D. Griffin, and R. N. Funston. 2016. Estimation of calving date in beef cattle with real time ultrasound. Prof. Anim. Sci. 32:322-327.</p><br /> <p>Kruse, S. G., G. A. Bridges, B. J. Funnell, S. L. Bird, S. L. Lake, R. P. Arias, O. L. Amundson, E. L. Larimore, D. H. Keisler, and G. A. Perry. 2016. Influence of post-insemination nutrition on embryonic development in beef heifers. Theriogenology (R1 Submitted)</p><br /> <p>Lamb, G. C., V. R. G. Mercadante, D. D. Henry, P. L. P. Fontes, C. R. Dahlen, J. E. Larson, and N. DiLorenzo. 2016. Advantages of current and future reproductive technologies for beef cattle production. Prof. Anim. Sci. 32:162-171.</p><br /> <p>Larimore, E. L., O. L. Swanson, G. A. Bridges, A. K. McNeel, R. A. Cushman, and G. A. Perry. 2016. Changes in ovarian function associated with circulating concentrations of estradiol before a GnRH-induced ovulation in beef cows. Domest. Anim. Endo. (In press).</p><br /> <p>Leiva, T. R. F. Cooke, A. P. Brand&atilde;o, U. Pardelli, R. O. Rodrigues, F. N. Corr&aacute;, and J. L. M. Vasconcelos. 2016. Effects of concentrate type and chromium propionate Supplementation on insulin sensitivity parameters, milk production, and reproductive outcomes of lactating dairy cows consuming excessive energy. Animal 10. 1017/S1751731116001713</p><br /> <p>Leiva, T., R. F. Cooke, A. P. Brand&atilde;o, A. C. Aboin, J. Ranches, and J. L. M. Vasconcelos. 2015. Effects of excessive energy intake and Supplementation with chromium propionate on insulin resistance and reproductive parameters in lactating dairy cows. Livest. Prod. Sci 180:121-128.</p><br /> <p>Manthey, A. K., J. L. Anderson, and G. A. Perry. 2016. Feeding distillers dried grains in replacement of forage in limit-fed dairy heifer rations: Effects on growth performance, rumen fermentation, and total tract digestibility of nutrients. J. Dairy Sci. 99:7206&ndash;7215.</p><br /> <p>Marques, R. S., R. F. Cooke, M. C. Rodrigues, B. I. Cappellozza, C. K. Larson, P. Moriel, and D. W. Bohnert. 2016. Effects of organic or inorganic Co, Cu, Mn, and Zn Supplementation to late-gestating beef cows on productive and physiological responses of the offspring. J. Anim. Sci. 94:1215-1226.</p><br /> <p>Marques, R. S., R. F. Cooke, M. C. Rodrigues, P. Moriel, and D. W. Bohnert. 2016. Impacts of cow body condition score during gestation on weaning performance of the offspring. Livest. Prod. Sci. 191:174-178.</p><br /> <p>Mayer, J. J., J. D. Davis, J. L. Purswell, E. J. Koury, N. H. Younan, J. E. Larson, and T. M. Brown-Brandl. 2016. Development and characterization of a continuous tympanic temperature logging (CTTL) probe for bovine animals. Transactions of the ASABE. 59:703-714. (DOI: 10. 13031/trans. 59. 11367).</p><br /> <p>McCracken, V. L., G. Xie, S. E. Deaver, L. H. Baumgard, R. P. Rhoads and M. L. Rhoads. 2015. Hepatic progesterone-metabolizing enzymes cytochrome progesterone50 2C and 3A in lactating cows during thermoneutral and heat stress conditions. J. Dairy Sci. 98:3152-3157.</p><br /> <p>McLean, K. J. M. S. Crouse, M. R. Crosswhite, D. N. Black, C. R. Dahlen, P. Borowicz, L. R. Reynolds, A. K. Ward, B. W. Neville, and J. S. Caton. 2016. Rapid Communication: Expression of an endogenous retroviral element, syncytin-Rum1, during early gestation in beef heifers. doi: 10. 2527/jas. 2016-0793; Date posted: August 12, 2016.</p><br /> <p>Mercadante, V. R. G., L. E. Kozicki, F. M. Ciriaco, D. D. Henry, C. R. Dahlen, M. R. Crosswhite, J. E. Larson, B. E. Voelz, D. J.Patterson, G. A. Perry, R. N. Funston, T. L. Steckler, S. L. Hill, J. S. Stevenson, and G. C. Lamb. 2015. Effects of administration of prostaglandin F2&alpha; at initiation of the seven-day COSynch+ controlled internal drug release ovulation synchronization protocol for suckled beef cows and replacement heifers. J. Anim. Sci. 93:5204-5213.</p><br /> <p>Mercadante, V. R. G., P. L. P. Fontes, F. M. Ciriaco, D. D. Henry, P. Moriel, A. D. Ealy, S. E. Johnson, N. DiLorenzo, and G. C. Lamb. 2016. Effects of recombinant bovine somatotropin administration at breeding on cow, conceptus and subsequent offspring performance of beef cattle. J. Anim. Sci. 94:2128-2138.</p><br /> <p>Meyer, A. M., and P. J. Gunn. 2015. Making more but using less: The future of the U. S. beef industry with a reduced cow herd and the challenge to feed the United States and world. J. Anim. Sci. 93:4223-4226.</p><br /> <p>Muth-Spurlcok, A. M., J. A. Dix, M. P. T. Coleson, C. G. Hart, C. O. Lemley, T. M. Schulmeister, G. C. Lamb, and J. E. Larson. 2016. The effect of follicular wave on fertility characteristics in beef cattle. J. Anim. Sci. (Submitted).</p><br /> <p>Muth-Spurlock, A. M., A. N. Montgomery, T. M. Schulmeister, G. C. Lamb, J. Block, C. O. Lemley, J. M. Feugang, and J. E. Larson.2016. Characteristics of ovulatory and non-ovulatory dominant follicles among beef cows exhibiting two and three follicular waves. Domest. Anim. Endo. (Submitted).</p><br /> <p>Nielson, H. R., A. F. Summers, and R. N. Funston. 2016. A comparison of two implant protocols; Synovex-Choice/Synovex-Plus vs. Synovex-S/Revalor-S on steer feedlot performance and carcass characteristics. Prof. Anim. Sci. 32:63-66.</p><br /> <p>Nielson, H. R., D. J. Kelly, and R. N. Funston. 2016. Effect of delayed insemination of nonestrus beef heifers in a melengestrol acetate-prostaglandin F2&alpha; timed artificial insemination protocol. Prof. Anim. Sci. 32:445-447.</p><br /> <p>Perry, G. A. 2016. Factors affecting puberty in replacement beef heifers. Theriogenology 86:373-378.</p><br /> <p>Perry, G. A. and R. A. Cushman. 2016. Use of ultrasonography to make management decisions. Prof. Anim. Sci. Prof. Anim. Sci. 32:154-161.</p><br /> <p>Perry, G. A. B. L. Perry, and J. A. Walker. 2016. Post-insemination diet change on reproductive performance in beef heifers. Prof. Anim. Sci. Prof. Anim. Sci. 32:316-321.</p><br /> <p>Perry, G. A., and R. A. Cushman. 2016. Use of ultrasonography to make reproductive management decisions. Prof. Anim. Sci. 32:154-161.</p><br /> <p>Reese, S. T., M. C. Pereira, J. L. Vasconcelos, M. F. Smith, J. A. Green, T. W. Geary, R. F. G Peres, G. A. Perry, and K. G. Pohler. 2016. Markers of pregnancy: how early can we detect pregnancies using pregnancy-associated glycoproteins (PAGs) and microRNAs. Anim. Reprod. Sci. (In press).</p><br /> <p>Reis, M. M., R. F. Cooke, B. I. Cappellozza, R. S. Marques, T. A. Guarnieri Filho, M. C. Rodrigues, J. S. Bradley, C. J. Mueller, D. H. Keisler, S. E. Johnson, and D. W. Bohnert. 2015. Creep-feeding to stimulate metabolic imprinting in nursing beef heifers: Impacts on heifer growth, reproductive, and physiological parameters. Animal 9:1500-1508.</p><br /> <p>Richardson, B. N., S. L. Hill, J. S. Stevenson, G. D. Djira, and G. A. Perry. 2016. Expression of estrus before fixed-time AI affects conception rates and factors that impact expression of estrus and the repeatability of expression of estrus in sequential breeding seasons. Anim. Reprod. Sci. 166:133-140.</p><br /> <p>Roberts, A. J., R. N. Funston, E. E. Grings, and M. K. Petersen. 2016. Beef heifer development systems and lifetime productivity. J. Anim. Sci. 94:2705-2715.</p><br /> <p>Santos, V. G., P. D. Carvalho, C. Maia, B. Carneiro, A. Valenza, P. M. Crump, and P. M. Fricke. 2016. Adding a second prostaglandin F2&alpha; treatment to but not reducing the duration of a PRID‐Synch protocol increases fertility after resynchronization of ovulation in lactating Holstein cows. J. Dairy Sci. 99:3869‐3879.</p><br /> <p>Sauls, J. A., B. E. Voelz, S. L. Hill, L. G. D. Mendon&ccedil;a, and J. S. Stevenson. 2016. Increasing estrus expression in the lactating dairy cow. J. Dairy Sci. 99 (Accepted).</p><br /> <p>Schubach, K. M., R. F. Cooke, A. P. Brand&atilde;o, K. D. Lippolis, L. G. T. da Silva, R. S. Marques, and D. W. Bohnert. 2016. Impacts of stocking density on development and puberty attainment of replacement beef heifers. J. Anim. Sci. (In review).</p><br /> <p>Schulz, L. L., C. E. Andresen, and P. J. Gunn. 2016. Factors affecting timing and intensity of calving season of beef cow-calf producers in the Midwest. Prof. Anim. Sci. 32:430-437.</p><br /> <p>Stevenson, J. S. 2016. Ovarian characteristics and timed artificial insemination pregnancy risk after presynchronization with gonadotropin-releasing hormone 7 days before PGF2a in dairy cows. Theriogenology 85:1139-1146.</p><br /> <p>Stevenson, J. S. 2016. Synchronization and artificial insemination strategies in dairy herds. Vet. Clin. Food Anim. http://dx. doi. org/10. 1016\j. cvfa. 2016. 01. 007.</p><br /> <p>Stevenson, J. S., and G. C. Lamb. 2015. Contrasting effects of progesterone on fertility of dairy and beef cows. J. Dairy Sci. 99:5951-5964.</p><br /> <p>Stevenson, J. S., and S. L. Pulley. 2016. Feedback effects of estradiol and progesterone on ovulation and fertility after gonadotropin-releasing hormone-induced release of luteinizing hormone. J. Dairy Sci. 99:3003-3015.</p><br /> <p>Stevenson, J. S., S. L. Hill, G. A. Bridges, J. E. Larson, and G. C. Lamb. 2015. Progesterone status, parity, body condition, and days postpartum before estrus or ovulation synchronization in suckled beef cattle influence artificial insemination pregnancy outcomes. J. Anim. Sci. 93:2111-2123.</p><br /> <p>Swanson, T. J., L. A. Lekatz, M. L. Van Emon, G. A. Perry, C. S. Schauer, K. R. Maddock Carlin, C. J. Hammer, and K. A. Vonnahme. 2016. Supplementation of metabolizable protein during late gestation on ewe organ mass and blood parameters. Domest. Anim. Endo. (In press)</p><br /> <p>Tait, R. G., Jr., R. A. Cushman, A. K. McNeel, E. Casas, T. P. L. Smith, H. C. Freetly, and G. L. Bennett. 2016. Estimates of epistatic and pleiotropic effects of casein alpha s1 (CSN1S1) and thyroglobulin (TG) genetic markers on beef heifer performance traits enhanced by selection. J. Anim. Sci. 94:920-926.</p><br /> <p>Thomas, J. M., B. E. Bishop, J. M. Abel, M. R. Ellersieck, M. F. Smith, and D. J. Patterson. 2016. The 9-day CIDR-PG protocol: Incorporation of PGF2&alpha; pretreatment into a long-term progestin based estrus synchronization protocol for postpartum beef cows. Theriogenology 85: 1555-1561.</p><br /> <p>Tucker, H. L., C. L. Parsons, S. Ellis, M. L. Rhoads and R. M. Akers. 2016. Tamoxifen impairs prepubertal mammary development and alters expression of estrogen receptor &alpha; (ESR1) and progesterone receptors (PGR). Domest. Anim. Endo. 54:95-105.</p><br /> <p>Vallet, J. L., J. A. Calder&oacute;n-D&iacute;az, K. J. Stalder, C. Phillips, R. A. Cushman, J. R. Miles, L. A. Rempel, G. A. Rohrer, C. A. Lents, B. A. Freking and D. J. Nonneman. 2016. Litter-of-origin trait effects on gilt development. J. Anim. Sci. 94:96-105.</p><br /> <p>Voelz, B., C. E. Payne, L. Hulbert, J. S. Stevenson, M. Brouk, and L. G. D. Mendon&ccedil;a. 2016. Kansas dairy producers&rsquo; needs survey: Reproductive management of Kansas dairy farms. J. Extension. (Submitted.)</p><br /> <p>Voelz, B., L. Rocha, F. Scortegagna, J. S. Stevenson, and L. G. D. Mendon&ccedil;a. 2016. Treatment of lactating dairy cows with gonadotropin-releasing hormone before first insemination during summer heat stress. J. Dairy Sci. 99: Published online: June 8, 2016.</p><br /> <p>Xie, G., L. C. Cole, L. D. Zhao, M. V. Skrzypek, S. R. Sanders, M. L. Rhoads, L. H. Baumgard and R. P. Rhoads. 2016. Skeletal muscle and hepatic insulin signaling is maintained in heat-stressed lactating Holstein cows. J. Dairy Sci. doi: 10. 3168/jds. 2015-10464.</p><br /> <p>Xie, M., S. R. McCoski, S. E. Johnson, M. L. Rhoads and A. D. Ealy. 2015. Combinatorial effects of epidermal growth factor, fibroblast growth factor 2, and insulin-like growth factor 1 on trophoblast cell proliferation and embryogenesis in cattle. Reprod. Fertil. Dev. doi: 10. 1071/RD15226.<br /><br /></p><br /> <p>Extension Reports/Publications</p><br /> <p>Cline, G. F., A. M. Muth-Spurlock, B. E. Voelz, C. O. Lemley, and J. E. Larson. 2016. Evaluating blood perfusion of the corpus luteum in beef cows during fescue toxicosis. MSU Beef Unit 2016 Research Roundup pp. 7.</p><br /> <p>Cooke, R. F. 2015. Dystocia in Beef Females. In: Cattle Producer&rsquo;s Handbook, 456.</p><br /> <p>Cooke, R. F. 2015. Feeding gestating beef cows trace minerals aids calf. Feedstuffs 87(40):12-14.</p><br /> <p>Cooke, R. F. 2015. Handling Calving Difficulties. In: Cattle Producer&rsquo;s Handbook, 447.</p><br /> <p>Cooke, R. F. 2015. Hot to select cattle for temperament. In: Cattle Producer&rsquo;s Handbook, 830.</p><br /> <p>Cooke, R. F. 2015. Impacts of organic and inorganic Co, Cu, Mn, and Zn supplementation to gestating beef cows on offspring performance: potential fetal programming effects? Oregon Beef Producer, December 2015, pp. 28-32.</p><br /> <p>Cooke, R. F. and J. Sprinkle. 2015. How to select and manage replacement heifers. In: Cattle Producer&rsquo;s Handbook, 745.</p><br /> <p>Cooke, R. F. Beef cattle nutrition: opportunities for improving reproductive efficiency. Select Sires Roy Wallace Symposium, Plain City, OH (10/2015).</p><br /> <p>Cooke, R. F. Impacts of temperament on reproductive performance of Bos indicus and B. taurus beef females. Beef Improvement Federation &ndash; NAAB Symposium, Biloxi, MS (06/2015)</p><br /> <p>Cooke, R. F. Impacts of temperament on reproductive performance of Bos indicus and B. taurus beef females. Joint Annual Meeting, Extension symposium, Salt Lake City, UT (07/2016).</p><br /> <p>Cooke, R. F. Influences of cattle temperament on performance. Montana Nutrition Conference 2016, Bozeman, MT (04/2016).</p><br /> <p>Cooke, R. F. Ionophores to optimize reproductive efficiency in beef females. Zoetis Research Group Brazil, Caldas Novas, OG, Brazil (8/2016).</p><br /> <p>Cooke, R. F. Nutrition of Gestating Beef Cows to Optimize Offspring Productivity. Coos County Cattlemen&rsquo;s Meeting, Myrtle Point, OR (11/2015).</p><br /> <p>Cooke, R. F. Nutrition of Gestating Beef Cows to Optimize Offspring Productivity. Oregon 2015 Beef Industry Tour (4 presentations total; 12/2015).</p><br /> <p>Cooke, R. F. Nutritional and management strategies for developing beef heifers: post-weaning phase. Annual conference novos enfoques na producao e reproducao de bovinos. Uberlandia, MG, Brazil (03/2016).</p><br /> <p>Cooke, R. F. Nutritional and management strategies for developing beef heifers: pre-weaning phase. Annual conference novos enfoques na producao e reproducao de bovinos. Uberlandia, MG, Brazil (03/2016).</p><br /> <p>Cooke, R. F. Nutritional and management strategies to optimize productivity of beef cows. Annual conference novos enfoques na producao e reproducao de bovinos. Uberlandia, MG, Brazil (03/2016). Impacts of temperament on reproductive performance of Bos indicus and B. taurus beef females. Lane County Cattlemen&rsquo;s Meeting, Eugene, OR (02/2015)</p><br /> <p>Cooke, R. F. Supplementing Trace Minerals to Beef Cows. National Cattlemen&rsquo;s Beef Association Cattlemen&rsquo;s College, San Diego, CA (01/2016).</p><br /> <p>Dairy Cattle Reproduction Council, Columbus, OH (November 8-9, 2016)</p><br /> <p>Dohlman, T. and P. Gunn. Research update: Use of pyrethroids in heifers. Iowa Beef Center &ndash; Growing Beef Newsletter. April, 2016. Available at: http://www.iowabeefcenter.org/growingbeef.html</p><br /> <p>Dohlman, T. M., M. Jahnke, J. West, P. E. Phillips, and P. J. Gunn. 2016. Effects of Label-Dose Permethrin Administration on Reproductive Function and Embryo Quality on Superovulated Beef Heifers. Animal Industry Report: AS 662, ASL R3050. Available at: http://lib.dr.iastate.edu/ans_air/vol662/iss1/11</p><br /> <p>Fricke, P. M. 2016. Alta Dairy Showcase. June 17, Forestville, WI.</p><br /> <p>Fricke, P. M. 2016. Barriers to high fertility in high‐producing dairy herds. Zoetis Veterinarian Dairy Owner meeting, April 29, Madison, WI.</p><br /> <p>Fricke, P. M. 2016. Double‐Vision: Management of twinning in dairy cows. Proc. Ontario Association of Bovine Practitioners, April 14, Guelph, ON.</p><br /> <p>Fricke, P. M. 2016. Fertility programs to achieve high 21‐d pregnancy rates in high producing Holstein dairy herds. Zoetis Pennsylvania Dairy meetings, March 7‐10, Somerset, Strasburg, Spring Mills, Bedford, and Elliottsburg, Pennsylvania.</p><br /> <p>Fricke, P. M. 2016. Managing Fertility in Expanding Dairy Herds. MSD Ireland dairy vet meetings, May 24‐26, Armagh, Northern Ireland, Mullingar, Ireland, and Tipperary, Ireland.</p><br /> <p>Fricke, P. M. 2016. Managing reproduction in dairy cattle. Cornell Summer Dairy Institute, July 28, Ithaca, NY.</p><br /> <p>Fricke, P. M. 2016. Managing reproduction in dairy herds. AltaU UK, May 23, Bristol, U.K.</p><br /> <p>Fricke, P. M. 2016. Repro update. Alta Genetics / VAS meeting, March 30, Tulare, CA.</p><br /> <p>Fricke, P. M. 2016. Repro update. CRI Distributor University, May 17, Mt. Horeb, WI.</p><br /> <p>Fricke, P. M. 2016. Repro update. CRI University, May 17, Mt. Horeb, WI.</p><br /> <p>Fricke, P. M. 2016. Repro update. Zoetis UK Westpoint Farm Vets meeting, May 21, Dorking, UK.</p><br /> <p>Fricke, P. M. 2016. Reproductive programs to maximize fertility in dairy cows. Proc. Large Dairy Herd Management Conference, May 2‐4, Oakbrook, IL.</p><br /> <p>Fricke, P. M. and J. R. Pursley. 2016. BRED Veterinary Workshop. June 9, Montebello, Quebec, Canada.</p><br /> <p>Fricke, P. M. and M. C. Wiltbank. 2016. Managing reproduction using the latest technologies. Parnell dairy farmer and vet meetings, July 12‐14, Napa Valley, CA.</p><br /> <p>Fricke, P. M. M. C. Wiltbank, P. D. Carvalho, and J. O. Giordano. 2016. Fertility programs to achieve high 21‐d pregnancy rates in high‐producing dairy herds. Elanco Dairy Meetings, April 25‐27, Decorah, IA, St. Cloud, MN, Red Wing, MN.</p><br /> <p>Fricke, P. M., A. Ricci, and P. D. Carvalho. 2016. Factors associated with pregnancy associated glycoprotein levels in plasma and milk of Holstein cows during early pregnancy and their impact on the accuracy of pregnancy diagnosis. Proc. Central Canadian Veterinary Conference, February 5, Winnipeg, MB.</p><br /> <p>Fricke, P. M., M. C. Wiltbank, P. D. Carvalho, and G. O. Giordano. 2015. Fertility programs to achieve high 21‐d pregnancy rates in high‐producing Holstein dairy herds. Proc. Minnesota Veterinary Medical Association Meeting, February 6, Minneapolis, MN.</p><br /> <p>Fricke, P. M., M. C. Wiltbank, P. D. Carvalho, and J. O. Giordano. 2016. Fertility programs to achieve high 21‐d pregnancy rates in high‐producing dairy herds. Proc. Central Canadian Veterinary Conference, February 5, Winnipeg, MB.</p><br /> <p>Fricke, P. M., M. C. Wiltbank, P. D. Carvalho, and J. O. Giordano. 2016. Fertility programs to achieve high 21‐d pregnancy rates in high‐producing dairy herds. Proc. Mid‐Atlantic States Bovine Conference, April 1, Hagarstown, MD.</p><br /> <p>Fricke, P. M., M. C. Wiltbank, P. D. Carvalho, and J. O. Giordano. 2016. Fertility programs to achieve high 21‐d pregnancy rates in high‐producing dairy herds. Proc. Ontario Association of Bovine Practitioners, April 14, Guelph, ON.</p><br /> <p>Fricke, P. M., P. D. Carvalho, and J. O. Giordano. 2016. Fertility programs to achieve high 21‐d pregnancy rates in high‐producing dairy herds. Proc. Four‐State Dairy Nutrition &amp; Management Conference, June 15‐16, Dubuque, IA. pp. 68‐74.</p><br /> <p>Funston, R., American Association of Bovine Practitioners Annual Meeting, AABP, Baton Rouge, LA, "Fetal Programming-Implications for Beef Production", Outreach, Workshop, Regional, Invited. (September 18, 2015).</p><br /> <p>Funston, R., Arthur County Producer Meeting. Arthur, NE. Increasing Production Efficiency Through Reproductive Management. (2/17/2016).</p><br /> <p>Funston, R., Boehringer Ingleheim producer meeting. Dallas, TX. Increasing Production Efficiency Through Reproductive Management. (2/27/2016).</p><br /> <p>Funston, R., Boehringer Ingleheim producer meeting. Eden, SD. Increasing Production Efficiency Through Reproductive Management. (2/23/2016).</p><br /> <p>Funston, R., Boehringer Ingleheim producer meeting. Miller, SD. Increasing Production Efficiency Through Reproductive Management. (1/21/2016).</p><br /> <p>Funston, R., Boehringer Ingleheim producer meeting. Zell, SD. Increasing Production Efficiency Through Reproductive Management. (1/21/2016).</p><br /> <p>Funston, R., Calving Distribution Conference, UNL, MARC, Clay Center, MARC, "Importance of calving distribution", Extension, Seminar, Regional, Invited. (September 3, 2015).</p><br /> <p>Funston, R., Chile Producer Tour, UNL Extension, North Platte, "Beef Systems Research", Extension, Other, Regional, Invited. (September 2, 2015).</p><br /> <p>Funston, R., Great Plains Livestock Consulting meeting, Denison, IA. Heifer Development Systems. (1/13/2016).</p><br /> <p>Funston, R., Great Plains Livestock Consulting meeting, Emmetsburg, IA. Heifer Development Systems. (1/12/2016).</p><br /> <p>Funston, R., Husker Harvest Days, Nebraska Gelbvieh Association, Grand Island, NE, "Beef Cattle Depreciation", Outreach, Workshop, Regional, Invited. (September 15, 2015).</p><br /> <p>Funston, R., Idaho FFA Tour, UNL Extension, North Platte, "Beef Systems Research", Extension, Other, Regional, Invited. (October 24, 2015).</p><br /> <p>Funston, R., Irish Producer Tour, UNL Extension, Gudmundsen Sandhills Laboratory, "Beef Systems Research", Extension, Other, Regional, Invited. (October 6, 2015).</p><br /> <p>Funston, R., Kentucky Veterinary Association Annual Convention, KVMA, Louisville, KY, "Increasing Beef Production Efficiency", Outreach, Workshop, National, Invited. (September 26, 2015).</p><br /> <p>Funston, R., Kentucky Veterinary Association Annual Meeting, KVMA, Louisville, KY, "Synchronization Systems", Outreach, Workshop, National, published in proceedings, Invited. (September 26, 2015).</p><br /> <p>Funston, R., KY Cattlemen&rsquo;s Convention. Owensborro, KY. Increasing Production Efficiency Through Reproductive Management. (1/15/2016).</p><br /> <p>Funston, R., Minnesota Veterinary Medical Association Annual Meeting. Minneapolis, MN. Increasing Production Efficiency Through Reproductive Management. (2/6/2016).</p><br /> <p>Funston, R., ND Stockgrowers Cattlemen's College, Zoetis, Bismarck, ND, "Heifer Development Systems", Extension, Seminar, Regional, Invited. (September 24, 2015).</p><br /> <p>Funston, R., NE College of Technical Agriculture Vet Tech CE Meeting, NCTA, Curtis, "Increasing Beef Production Efficiency", Outreach, Workshop, National, Invited.</p><br /> <p>Funston, R., Northwest Oklahoma Beef Conference, OSU, Enid, OK, "Heifer Development Systems", Extension, Seminar, Regional, Invited. (October 29, 2015).</p><br /> <p>Funston, R., Panama Study Group. North Platte, NE. Beef Systems Research. (3/12/16).</p><br /> <p>Funston, R., Panhandle Cattlemen's Day, Merck, Merial, Zoetis, Boehringer, Gordon, "Beef Cattle Depreciation", Outreach, Workshop, Regional, Invited. (October 26, 2015).</p><br /> <p>Funston, R., Purina Producer Meeting, Purina, Holyoke, CO, "Increasing Beef Production Efficiency", Outreach, Workshop, National, Invited. (September 29, 2015).</p><br /> <p>Funston, R., Sandhills NE Cattlemen Affiliate Field Day, Sandhills Affiliate, Gudmundsen Sandhills Laboratory, "Beef Cattle Depreciation", Outreach, Workshop, National, Invited. (October 3, 2015).</p><br /> <p>Funston, R., Steele Veterinary Clinic Meeting, Zoetis, Steele, ND, "Beef Cattle Depreciation", Outreach, Workshop, Regional, Invited. (September 23, 2015).</p><br /> <p>Funston, R., Ultrasound Training for Veterinarians, UNL, MARC, Clay Center, MARC, "Importance of calving distribution", Extension, Seminar, Regional, Invited. (2/25/2016).</p><br /> <p>Funston, R., Western Canadian Veterinary Association Annual Convention, CANWEST, Bannff, Alberta, Canada, "Synchronization Systems", Outreach, Workshop, National, Invited. (October 19, 2015).</p><br /> <p>Funston, R., Zoetis Producer Meeting, Zoetis, Killdeer, ND, "Increasing Beef Production Efficiency", Outreach, Workshop, National, Invited. (September 22, 2015).</p><br /> <p>Grings, E. E., A. N. Sackey, D. W. Brake, and G. A. Perry. Comparison of camelina meal and distiller&rsquo;s dried grains with solubles in diet of beef replacement heifers. SDSU 2015 Beef Report 2015-04.</p><br /> <p>Grussing, T., A. Meyer, and P. J. Gunn. 2016. Effects of Supplementing Excess Amounts of Metabolizable Protein from a Moderately Abundant Rumen</p><br /> <p>Grussing, T.; A. Meyer, G. Perry, and P. J. Gunn. 2016. Relationship between Plasma Amino Acid Profile and Ovarian Function around the Time of Ovulation in Beef Cows. Animal Industry Report: AS 662, ASL R3046. Available at: http://lib.dr.iastate.edu/ans_air/vol662/iss1/7</p><br /> <p>Gunn, P. Beef production in the U.S. and function of the Iowa Beef Center: USFAO sponsored trip of Ukranian Farmers. November 13, 2015.</p><br /> <p>Gunn, P. Building a herd for the long haul. Iowa Beef Center &ndash; Growing Beef Newsletter. July, 2016. Available at: http://www.iowabeefcenter.org/growingbeef.html</p><br /> <p>Gunn, P. Bull selection philosophy. Dysart, IA. (March 7, 2016).</p><br /> <p>Gunn, P. Can feed efficiency and fertility co-exist? Missouri Livestock Symposium. (December 5, 2015).</p><br /> <p>Gunn, P. Cornstalks and fall breeding. Angus Journal- Angus Advisor. October, 2015, pp 164-165.</p><br /> <p>Gunn, P. Distillers grains in beef cow diets. Brazilian producer and academic group hosted by Summit Farms. Ames, IA. (July 29, 2016).</p><br /> <p>Gunn, P. Excess protein not a problem this breeding season? Iowa Beef Center &ndash; Growing Beef Newsletter. April, 2016. Available at: http://www.iowabeefcenter.org/growingbeef.html</p><br /> <p>Gunn, P. Getting serious about colostrum. Angus Journal- Angus Advisor. February, 2016, pp 190-191.</p><br /> <p>Gunn, P. Heifer selection- How to Target Longevity and Profit. Iowa Cattlemen&rsquo;s Association BeefMeets. Independence, Atlantic, and Riverside, IA. (June 23, 28, and 29, 2016).</p><br /> <p>Gunn, P. J., G. Dahlke, and Werner Family Angus. 2016. Managing Fertility and Longevity in the Beef Herd through Feed Efficiency. Driftless Region Beef Conference. Dubuque, IA, pp22-23.</p><br /> <p>Gunn, P. J.; A. L. Lundberg, R. A. Cushman, H. C. Freetly, O. L. Amundson, J. A. Walker, and G. A. Perry. 2016. Effect of Circulating Blood or Plasma Urea Nitrogen Concentrations on Reproductive Efficiency in Beef Heifers and Cows. Animal Industry Report: AS 662, ASL R3066. Available at: http://lib.dr.iastate.edu/ans_air/vol662/iss1/27</p><br /> <p>Gunn, P. Management to reduce calving difficulty. McNay Update for Veterinarians. Chariton, IA. (May 24, 2016)</p><br /> <p>Gunn, P. Managing Fertility and Longevity in the Beef Herd through Feed Efficiency. Driftless Region Beef Conference. Dubuque, IA. (February 4-5, 2016</p><br /> <p>Gunn, P. Maximizing your breeding season. McNay Fall field day. Chariton, IA. (August 2, 2016)</p><br /> <p>Gunn, P. Optimizing beef cattle nutrition from conception to consumption. Ensminger international conference for enhanced livestock production. Jointly conducted by Iowa State and Zamarano Universities. Zamarano, Honduras. (May 13-14, 2016).</p><br /> <p>Gunn, P. Pregnancy checking pays the bills. Iowa Cattleman- Cow-Calf Commentary August, 2016. p. 18.</p><br /> <p>Gunn, P. The post-AI nutrition slump. Iowa Beef Center &ndash; Growing Beef Newsletter. May, 2016. Available at: http://www.iowabeefcenter.org/growingbeef.html</p><br /> <p>Gunn, P. What is a bull worth? 2016 edition. Iowa Beef Center &ndash; Growing Beef Newsletter. March, 2016. Available at: http://www.iowabeefcenter.org/growingbeef.html</p><br /> <p>Gunn, P. Why deworm the cow? Merial Bovine Veterinary Symposium. San Diego, CA. (April 7-10, 2016).</p><br /> <p>Gunn, P. Why deworm the cow? Merial sales meeting. Postville, IA. (March 31, 2016).</p><br /> <p>Gunn, P., and L. Schulz. A heightened need for longevity in the cowherd. Iowa Beef Center &ndash; Growing Beef Newsletter. January, 2016. Available at: http://www.iowabeefcenter.org/growingbeef.html</p><br /> <p>Lamb, G. C. Advantages of current and future reproductive technologies for beef cattle production, Joint Annual Meeting, ARPAS Symposium, Orlando, FL</p><br /> <p>Lamb, G. C. Fetal Programming in Beef Cattle - Merial Producer Seminars, Crystal River, FL.</p><br /> <p>Lamb, G. C. Herd improvement utilizing AI vs. buying high quality bulls, Florida Heritage Beef Group &ndash; Okeechobee, FL</p><br /> <p>Lamb, G. C. Impacts of changing calving distribution on economic and reproductive efficiency. Alabama Farmers Federation Commodity Organizational Meeting, Montgomery, AL</p><br /> <p>Lamb, G. C. Impacts of estrous synchronization on cowherd performance. The Range Beef Cow Symposium XXIV, Loveland, CO</p><br /> <p>Lamb, G. C. Reproductive Management Considerations for Herd Expansion. Montana Nutrition Conference, Bozeman, MT.</p><br /> <p>Lamb, G. C. Reproductive Management for Beef Cattle (16 presentations in KS, IA, MT, OK, SD). ABS Global Inc. technical service training.</p><br /> <p>Lamb, G. C. Synchronization programs for heifers and cows, Florida Heritage Beef Group &ndash; Okeechobee, FL.</p><br /> <p>Lamb, G. C. The impacts of estrus synchronization on calving distribution. Kansas State University Cattlemen&rsquo;s Day, Manhattan, KS.</p><br /> <p>Lamb, G. C. The Reproduction and nutrition connection. National Cattlemen&rsquo;s Beef Association Cattlemen&rsquo;s College, San Diego, CA</p><br /> <p>Lamb, G. C. The role of reproductive technologies for herd expansion. American Angus Association Bootcamp, Marianna, FL.</p><br /> <p>Lamb, G. C. Use of reproductive technologies to improve economic efficiency of beef operations. Oregon Cow/Calf Seminar Series (4 presentations Oregon)</p><br /> <p>Lamb, G. C. Using Decision aids to implement AI in the beef herd. Alabama Farmers Federation Commodity Organizational Meeting, Montgomery, AL</p><br /> <p>Lamb, G. C. What Does It Take to Start an AI Program? &ndash; Beef Cattle Short Course, Gainesville, FL</p><br /> <p>Lamb, G. C., D. D. Henry, N. DiLorenzo, F. M Ciriaco, P. L. P. Fontes, V. R. G. Mercadante, and D. Mayo. 2015. Understanding Pregnancy Diagnosis in Beef Cattle. University of Florida, IFAS, Florida Coop. Ext</p><br /> <p>Lamb, G. C. 2015. W15th Annual Florida Bull Test Summary and Sale Information. Panhandle Ag e-News. http://nwdistrict.ifas.ufl.edu/phag/2015/01/09/15th-annual-florida-bull-test-summary-and-sale-information/</p><br /> <p>Lamb, G. C. 2015. What are the long-term impacts of estrus synchronization and artificial insemination? Panhandle Ag e-News. http://nwdistrict.ifas.ufl.edu/phag/2015/10/09/what-are-the-long-term-impacts-of-es</p><br /> <p>Lamb, G. C. 2015. What does it take to start an AI program? University of Florida Beef Cattle Short Course http://animal.ifas.ufl.edu/beef_extension/bcsc/2015/speaker_proceedings/lamb.pdf</p><br /> <p>Lamb. G. C. Economics of AI vs. natural service: Using decision-aid tools. Applied Reproductive Strategies in Beef Cattle Symposium, Davis, CA</p><br /> <p>Lamb. G. C. Reproductive Management of Commercial Cows, North Florida Cattlemen&rsquo;s Association Quarterly Meeting, Live Oak, FL.</p><br /> <p>Larson, J. Assessing the Economic Impacts of Estrus Synchronization and Fixed-Time AI in Beef Production Systems. Beef Improvement Federation &ndash; NAAB Symposium, Biloxi, MS.</p><br /> <p>Larson, J. E. 2015. Using ultrasonography in research applications. Mississippi</p><br /> <p>Larson, J. E. 2016. Using ultrasonography in research applications. Louisiana Farm Bureau Member Tour, Mississippi State, MS.</p><br /> <p>Larson, J. E. 2016. Using ultrasonography in research applications. Mississippi Hereford Association Field Day, Mississippi State, MS.</p><br /> <p>Larson, J. E. Farm Bureau Federation Board of Directors, Mississippi State, MS.</p><br /> <p>Mercadante, V. ABS Global Beef Meetings, Madison and Jefferson City, MO. Speaker: The economic advantages of implementing TAI. March 9 and 10, 2016.</p><br /> <p>Mercadante, V. Blue Ridge Cattlemen&rsquo;s Association. Beef 20/20 series. Upperville, VA. Speaker: Improving reproductive efficiency with applied reproductive technologies, fetal programming and how it can effect beef production. April 6, 2016.</p><br /> <p>Mercadante, V. KSU, Southeast Research and Extension Center. Heifer and Cow Breeding Meeting. Parsons, KS. Speaker: Managing cow synchronization with a real-life cow herd. February 23, 2016.</p><br /> <p>Mercadante, V.R.G., D.D. Henry, F.M. Ciriaco, P.L.P. Fontes, N. Oosthuizen, and G.C. Lamb. 2016. Estrous Synchronization and Fixed-Time Artificial Insemination. University of Florida, IFAS, Florida Coop. Ext.</p><br /> <p>Montgomery, A., A. M. Muth-Spurlock, C. Hart, M. Coleson, C. O. Lemley, and J. E. Larson. 2016. Effect of antral follicle count on growth characteristics of follicles and concentrations of steroid hormones in follicular fluid of beef cows. MSU Beef Unit 2016 Research Roundup pp. 9.</p><br /> <p>Muth-Spurlock, A. M., C. Hart, C. O. Lemley, and J. E. Larson. 2016. The effects of follicular wave on characteristics of fertility in beef cattle. MSU Beef Unit 2016 Research Roundup pp. 10.</p><br /> <p>Muth-Spurlock, A. M., C. O. Lemley, and J. E. Larson. 2016. Differences in blood perfusion, growth characteristics, and steroid hormones among anovulatory dominant follicles that emerge under basal or luteal concentrations of progesterone in beef cattle. MSU Beef Unit 2016 Research Roundup pp. 8.</p><br /> <p>Patterson, D. J. Control of estrus and ovulation in beef cows. American Veterinary Medical Association Meetings. August 8, 2016. San Antonio, TX.</p><br /> <p>Patterson, D. J. Control of estrus and ovulation in beef heifers. American Veterinary Medical Association Meetings. August 8, 2016. San Antonio, TX.</p><br /> <p>Patterson, D. J. Expediting genetic improvement in beef cattle with fixed-time artificial insemination. Georgia Angus Convention. January 23, 2016. Athens, GA.</p><br /> <p>Patterson, D. J. Management strategies for adding value to beef heifers: A working model. American Veterinary Medical Association Meetings. August 8, 2016. San Antonio, TX.</p><br /> <p>Patterson, D. J. Management strategies for adding value to beef heifers: A working model. Food Animal Conference, University of Georgia College of Veterinary Medicine. March 19, 2016. Tifton, GA.</p><br /> <p>Patterson, D. J. Opportunities to enhance pregnancy rates resulting from fixed-time AI. Food Animal Conference, University of Georgia College of Veterinary Medicine. March 19, 2016. Tifton, GA.</p><br /> <p>Patterson, D. J. Physiological and management advances enhancing adoption of applied reproductive management procedures in beef cattle. Joint Annual Meeting American Societies of Animal and Dairy Science. July 21, 2016. Salt Lake City, UT.</p><br /> <p>Patterson, DJ, JM Thomas, BE Bishop, JM Abel, and MF Smith. 2015. Control of estrus and ovulation in beef heifers. In: Proceedings, Applied Reproductive Strategies in Beef Cattle. August 17-18, 2015. Davis, CA. pp. 36-67.</p><br /> <p>Patterson, DJ, JM Thomas, BE Bishop, JM Abel, JE Decker, and MF Smith. Control of estrus and ovulation in beef cows. In: Proceedings, Applied Reproductive Strategies in Beef Cattle. August 17-18, 2015. Davis, CA. pp. 68-105.</p><br /> <p>Perry, G. A. 2015 Interstate Veterinary Conference. Alternative Management Systems: The Good and The Bad; Current Advances in Estrous Synchronization; Fetal Programing: What do we know?</p><br /> <p>Perry, G. A. 2015 Science and Solutions Symposium. Banff, Canada. Title &ldquo;Vaccinating with a Modified Live &ndash; How it can Impact Reproductive Efficiency&rdquo;</p><br /> <p>Perry, G. A. Academy of Veterinary Consultants conference Kansas City, Mo August 2016</p><br /> <p>Perry, G. A. Applied Reproductive Strategies in Beef Cattle Conference. 2015. Davis, California &ldquo;Management Factors that Impact the Efficiency and Applied Reproductive Technologies&rdquo;</p><br /> <p>Perry, G. A. British Society of Animal Science. Chester, England. 2016. Title&rdquo; Reproductive management of beef heifers.&rdquo;</p><br /> <p>Perry, G. A. Merial 2016 Bovine Veterinary Symposiums. Tempe, Arizona and Miami, Florida &ldquo;Impact of Nutrition on Reproductive Success and Fetal Programing.&rdquo;</p><br /> <p>Rhoads, M. American Association of Bovine Practitioners Hands on Embryo Transfer School; Physiology of superovulation and synchronization. Instructor, Virginia-Maryland College of Veterinary Medicine, August 10, 2016.</p><br /> <p>Rhoads, M. American Association of Bovine Practitioners Hands on Embryo Transfer School; Physiology of superovulation and synchronization. Instructor, Virginia-Maryland College of Veterinary Medicine, August 17, 2015.</p><br /> <p>Richardson, B.N., S. L. Hill, J. S. Stevenson, G. D. Djira, and G. A. Perry. Importance of estrus expression before fixed-time AI on conception rates in beef cattle. SDSU 2015 Beef Report 2015-01.</p><br /> <p>Schulz, L. L., C. E. Andresen, and P. J. Gunn. 2016. Factors Affecting Timing and Intensity of Calving Season of Beef Cow-Calf Producers in the Midwest. Animal Industry Report: AS 662, ASL R3053. Available at: http://lib.dr.iastate.edu/ans_air/vol662/iss1/14</p><br /> <p>Smith, MF, GA Perry, KG Pohler, SE Dickinson, and DJ Patterson. 2015. Establishment of pregnancy in beef cattle: Application of basic principles. In: Proceedings, Applied Reproductive Strategies in Beef Cattle. August 17-18. Davis, CA. pp. 9-35.</p><br /> <p>Stevenson, J. S. 70th Annual Conference for Veterinarians (KVMA) (June 7-8, 2016)</p><br /> <p>Stevenson, J. S. Parnell Sales Meeting, Overland Park, KS (May 24, 2016)</p><br /> <p>Stevenson, J. S. Physiological and management advances enhancing adoption of applied reproductive management procedures in dairy cattle. Joint Annual Meeting American Societies of Animal and Dairy Science. July 21, 2016. Salt Lake City, UT.<br /><br /></p><br /> <p>Stevenson, J. S. KSU College of Veterinary Medicine AABP student group (February 8, 2016)</p><br /> <p>&nbsp;</p><br /> <p>Articles in the Popular Press (non-peer reviewed)</p><br /> <p>Fricke, P. M. 2016. Strategies for Nonpregnancy Diagnosis in Dairy Cows. Hoard&rsquo;s Dairyman Webinar, May 9.</p><br /> <p>Gunn, P. Maximizing the value of estrous synchronization. Angus Journal- Angus Advisor. May, 2016. Pp 82-83.</p><br /> <p>Gunn, P. New management practices for the New Year. Angus Journal- Angus Advisor. January, 2016. Pp 124-125.</p><br /> <p>Gunn, P. New Year&rsquo;s resolutions. Angus Journal- Angus Advisor. December, 2015. Pp 77-78.</p><br /> <p>Gunn, P. nutritionally preparing for spring calving. Angus Journal- Angus Advisor. November, 2015, pp 84-85.</p><br /> <p>Gunn, P. Parasite control Part 1. Angus Journal- Angus Advisor. June, 2016. p.68.</p><br /> <p>Gunn, P. Parasite control Part 2. Angus Journal- Angus Advisor. July, 2016. p.58.</p><br /> <p>Gunn, P. Revisiting vitamins. Angus Journal- Angus Advisor. September, 2015. p.252.</p><br /> <p>Lamb, G.C. 2015. How have early reproductive developments affected beef production systems? The Florida Cattlemen and Livestock Journal 80:42-46.</p><br /> <p>Lamb, G.C. 2015. Options for diagnosis of pregnancy for beef cattle. The Florida Cattlemen and Livestock Journal 79:8-14.</p><br /> <p>Lamb, G.C. 2015. Pregnancy diagnosis options for beef cattle producers. Panhandle Ag e-News. http://nwdistrict.ifas.ufl.edu/phag/2015/05/22/pregnancy-diagnosis-options-for-beef-cattle-producers/</p><br /> <p>Lamb, G.C. 2015. Reducing the breeding season using reproductive technologies &ndash; A case study. The Florida Cattlemen and Livestock Journal 79:32-33.</p><br /> <p>Lamb, G.C. 2015. Repro Tracks &ndash; Advantages of Reproductive Technologies (1). Angus Journal (September 2015:264-266)</p><br /> <p>Lamb, G.C. 2015. Repro Tracks &ndash; Advantages of Reproductive Technologies (2). Angus Journal (October 2015:178-179)</p><br /> <p>Lamb, G.C. 2015. Repro Tracks &ndash; Heifer Development. Angus Journal (February 2015:140-141)</p><br /> <p>Lamb, G.C. 2015. Repro Tracks &ndash; Planning for the Breeding Season. Angus Journal (April 2015:134-136).</p><br /> <p>Lamb, G.C. 2015. Reducing the breeding season using reproductive technologies &ndash; A case study. The Florida Cattlemen and Livestock Journal 79:32-33.</p><br /> <p>Lamb, G.C. 2015. Repro Tracks &ndash; Sexed Semen. Angus Journal (March 2015:202-204).</p><br /> <p>Lamb, G.C. 2015. Repro Tracks &ndash; Stress and Reproduction. Angus Journal (August 2015:90-93).</p><br /> <p>Lamb, G.C. 2015. What should producers consider when implementing an artificial insemination program in their operations? Braford News, Fall 2015, pp 16-18.</p><br /> <p>Lamb, G.C. 2016. Advanced reproductive technologies that may impact beef production systems in the near future. The Florida Cattlemen and Livestock Journal 80:52-56.</p><br /> <p>Stevenson, J. S. 2015. GnRH enhances presynch programs and preg rates. Hoard&rsquo;s Dairyman 160:632. October 10, 2016.</p><br /> <p>Stevenson, J. S. 2015. Research validates timed A.I. programs. Hoard&rsquo;s Dairyman 160:573. September 10, 2015.</p><br /> <p>Stevenson, J. S. 2015. When is the optimal time to run new-age preg tests? Hoard&rsquo;s Dairyman 160:726. November, 2015.</p><br /> <p>Stevenson, J. S. 2016. Body condition and body weight predict fertility. Hoard&rsquo;s Dairyman 161:253. April 10, 2016.</p><br /> <p>Stevenson, J. S. 2016. Celebrating 10 years of stepped-up reproduction. Hoard&rsquo;s Dairyman 161:25. January 10, 2016.</p><br /> <p>Stevenson, J. S. 2016. Critical points to monitor in your timed A.I. program. Hoard&rsquo;s Dairyman 161:90. February 10, 2016.</p><br /> <p>Stevenson, J. S. 2016. Delay timing of A.I. with sexed semen. Hoard&rsquo;s Dairyman 161:400. June, 2016.</p><br /> <p>Stevenson, J. S. 2016. Prepare for better summer production and reproduction. Hoard&rsquo;s Dairyman 161:333. May 10, 2016.</p><br /> <p>Stevenson, J. S. 2016. We&rsquo;re getting more cystic and aborted cows pregnant. Hoard&rsquo;s Dairyman 161:164. March 10, 2016.<br /><br /></p>

Impact Statements

1. Supplementing protein to beef cows as infrequent as once weekly did not reduce uterine flushing pH or plasma progesterone concentrations, which are known to impact reproduction in beef cows.

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Report Information

Participants

Cameron Locke – University of Missouri
Dave Patterson – University of Missouri
Emma Knickmeyer – University of Missouri
George Smith – Michigan State University
Jamie Larson – Mississippi State University
Jeff Stevenson – Kansas State University
Jordan Thomas – University of Missouri
Maria Haag – University of Missouri
Nicky Oosthuizen – University of Florida
Paul Fricke – University of Wisconsin
Pedro Fontes – University of Florida
Reinaldo Cooke – Oregon State University
Richard Pursley – Michigan State University
Rick Funston – University of Nebraska
Teresa Steckler – University of Illinois
Vitor Mercadante – Virginia Tech

Absent from the meeting
Turzillo, Adele – USDA-NIFA
Carl Dahlen – North Dakota State University
George Perry – South Dakota State University
Robert Cushman – USDA-MARC

Brief Summary of Minutes

See attached file for full NC1201 2016/2017 annual report.

 

--

NC 1201 – Annual Meeting (Portland, OR) – Minutes

 

2017 Officers

Reinaldo Cooke- Chair

Vitor Mercadante – Secretary

 

Attendees

Cameron Locke – MO (student)

Dave Patterson – MO

Emma Knickmeyer – MO (student)

George Smith – MI

Jamie Larson – MS

Jeff Stevenson – KS

Jordan Thomas – MO (student)

Maria Haag – MO (student)

Nicky Oosthuizen – FL (student)

Paul Fricke – WI

Pedro Fontes – FL (student)

Reinaldo Cooke - OR

Richard Pursley – MI

Rick Funston – NE

Teresa Steckler – IL

Vitor Mercadante – VA

 

08/17/17 – Introductions and Station Reports

George Smith – Associate Dean of Research, Michigan State University

Informed the renewal of the project and was very complementary of the group, especially the group’s collaborative efforts. Indicated the group should apply for the Regional Project Award.

 

Reinaldo Cooke – Oregon State University – EOARC

Ca-salts of soybean oil (CSOO) supplementation after FTAI in Bos taurus beef cows. Collaborative project between OSU and VT (Vitor Mercadante). Increase in pregnancy rates (9% points) for cows supplemented with CSOO, also increase in expression of ISG on day 21.

Estrus expression and intensity during FTAI protocols. Divided cows on No estrus and Estrus with high activity or low activity. High activity cows had larger follicles, increased CL volume and greater concentration of progesterone, greater pregnancy rates.

Possibility for collaboration among the group. Retrospective analysis of estrus expression in FTAI to look at repeatability of estrus of cows over breeding seasons.

 

Paul Fricke – University of Wisconsin

Ovsynch Protocol for dairy cows. Effects of progesterone concentration during the protocol on fertility. 15% of cows have impaired CL regression, and low fertility. Addition of a second PGF (dinoprost) injection 24 hrs after the first PGF injection increases luteolysis and improved pregnancy.

Low progesterone cows will have increased double ovulation rate and have greater fertility, but also increases twining rate.

Possibility for collaboration among the group. Investigate effects of low progesterone on fertility of dairy cows and double ovulation.

Rick Funston – University of Nebraska

Heifers born later in the breeding season (March vs May) will have decreased pregnancy rates, investigating supplementation strategies to resolve this issue. Effects of Multimin injection on pregnancy rates, no effects were found. Implanting heifers at 12 months of age with Revalor-G decreased pregnancy rates.

 

Jamie Larson – Mississippi State University

Effects of duration of progesterone (7 vs 14 day) exposure on hepatic enzyme activity for progesterone clearance.

Grazing dairy cows exercise effects on uterine artery blood flow, milk production and quality parameters. Exercise did not affect blood flow and milk parameters, but increased heart rate.

Possibility for collaboration among the group. CL regression differences between heifers and cows.

 

Vitor Mercadante – Virginia Tech

Split TAI with an 8 hr delay in GnRH and AI did not improve pregnancy rate. The use of a new AI sheath with 3 outputs did not improve pregnancy rates of beef heifers, but reduced semen reflux in the sheath compared to an AI sheath with a single semen output.

Dave Paterson, Jordan Thomas, Emma Knickmeyer, Cameron Locke – University of Missouri

Bos indicus influenced beef heifers, effects of long term progestin protocols. Long term progestin improved percentage of pubertal heifers at the beginning of the breeding season, across different repro-tract scores heifers.

Sex-sorted semen and 14-day CIDR and split TAI. Sexed semen had reduced pregnancy rate compared to conventional semen, but pregnancy rates were 52% and 60% respectively, which are acceptable pregnancy rates.

 

Nicky Oosthuizen, Pedro Fontes – University of Florida and Texas A&M

HiCON and regular PGF yielded similar pregnancy rates in beef heifers. Pre-synch with PGF 7 days before a 7d CO-Synch CIDR protocol, compared to regular 7d CO-Synch CIDR. Pre-synch reduced percentage of heifers showing estrus after CIDR removal, but did not change fertility.

Effects of increased IGF-1 during estrus synchronization and FTAI. Injection of 650 mg of bST concentration during synchronization reduces pregnancy rate in beef heifer. Effects of embryo and maternal breed on early embryonic development. Nutrient restriction during early gestation affects embryonic loss differently in Bos taurus and Bos indicus influenced recipients, with Bos taurus animals having greater embryonic loss when submitted to a restriction in nutrient intake.

 

Richard Pursley – Michigan State University

Simplification of dairy cow synchronization protocols. Adding the PGF with the GnRH during a pre-synch protocol did not affected pregnancy rate. Low progesterone during follicle development lead to increased pregnancy loss, after day 35.

Low progesterone during synchronization leads to increased double ovulation rate in dairy cows.

 

Visit to Oregon National Primate Research Center (ONPRC) – OHSU.

 

 

 

8/18/17

Adele Turzillo – USDA-NIFA

Update on USDA and NIFA personnel, budget, and funding programs.

 

Jeff Stevenson – Kansas State University

Pre-synch programs for lactating dairy cows using a 5 or 7 day Ovsynch program. Complete luteolysis are greater for cows treated with the 7-day vs. 5-day Ovsynch program regardless of frequency-dose of PGF (1 x 50 mg dose vs. 2 x 25 mg doses 24 h apart).

Split-time AI for beef cows. Delaying split-time AI from 55 and 75 hr to 65 and 85 hr, produced more pregnancies in beef cows.

 

Collaboration discussion

Bos indicus influenced cattle – strategies for synchronization, heifer development.

Estrus expression in beef females, repeatability of estrus expression.

Dose effect and differences between PGF products (cloprostenol and dinoprost) in luteolysis.

Use of sex semen in split-time AI programs for beef females.

 

Discussion regarding ASAS-ADSA split meetings. The group does not support the split and proposed timing the NC1201 meeting with the Mid-West ASAS meeting in March to support the joint meeting and provide students with more opportunities to interact and discuss science.

The group moved to propose a symposium at Mid-West meetings. We will try to have our meeting at the same venue as Mid-West meetings. It was suggested a visit to the Omaha zoo.

 

Symposium – NC1201-USDA Regional Project. Methods to Increase Reproductive Efficiency in Cattle.

Have 2 keynote speakers (1 beef and 1 dairy), and have students present abstracts.

Ideas for keynote - A review of the accomplishments of NC1201 and the collaborations (Jack Britt). How to address popular perception of using hormones in livestock production (Jim Lauderdale).

Business Meeting

2018 President – Vitor Mercadante

Jeff Stevenson nominates Richard Pursley for secretary, Vitor Mercadante seconded. Passed.

 

2018 Secretary elected – Richard Pursley

Rick Funston nominates Omaha, NE and dates of March 14 and 15. Vitor Mercadante seconded. Passed.

 

2018 NC1201 meeting date and location – March 14 and 15. Omaha, NE.

 

Accomplishments

Publications

Impact Statements

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