DEVELOP BEEF CATTLE BETTER SUITED FOR SUSTAINABLE PRODUCTION

• Sponsoring Institution: State Agricultural Experiment Station
• Project Status: COMPLETE
• Funding Source: STATE
• Reporting Frequency: Annual
• Accession No.: 0095775
• Project Start Date: Oct 1, 2003
• Project End Date: Sep 30, 2008
• Program Code: [(N/A)]- (N/A)

Recipient Organization
MONTANA STATE UNIVERSITY
(N/A)
BOZEMAN,MT 59717

Performing Department
FORT KEOGH LIVESTOCK & RANGE RESEARCH CENTER

Non Technical Summary
Rangeland agriculturalists' sustainability is tied closely to their ability to manage high levels of ecological and economical uncertainty over time and space. These uncertainties stem largely from the effects that temporal changes in climatic conditions both short and long-term, and spatial changes in topographic and edaphic factors have on quantity and quality of forage produced. These products will enhance rangeland agriculturalists' ability to reduce both the ecological and economic risks associated with their enterprises.

Animal Health Component

50%

Research Effort Categories

Basic

50%

Applied

50%

Developmental

(N/A)

Classification

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
301	3310	1080	40%
301	3310	1010	30%
301	3310	1020	30%

Knowledge Area
301 - Reproductive Performance of Animals;

Subject Of Investigation
3310 - Beef cattle, live animal;

Field Of Science
1010 - Nutrition and metabolism; 1080 - Genetics; 1020 - Physiology;

Keywords

forage

water

animal growth

livestock management

stocking levels

data

drought

beef cattle

forage quality

sustainable agriculture

animal nutrition

nutrient utilization

grazing

climate change

range management

environmental impact

economic impact

production systems

forage fed beef

prediction

seasonal variation

environmental stress

economic efficiency

quantitative genetics

gene loci

traits

selection systems

Goals / Objectives
1. Quantify relative impacts of climatic variation and livestock grazing on sustainability of Northern Great Plains rangeland ecosystems and develop management strategies to ameliorate selected economic and ecological risks resulting from adverse impacts. 2. Quantify impacts of management tactics designed to improve the supply of quality forage in relation to nutritional needs of cattle on performance of grazing cattle and related economic indicators. 3. Evaluate in vitro gas production techniques to estimate seasonal variation in forage quality and predict performance in rangeland-based beef cow production systems.

Project Methods
Field-laboratory studies will evaluate how plants respond to grazing and environmental stress. Role of rangelands and management tactics in regulating atmospheric carbon dioxide flux will be assessed by measuring temporal changes in plant biomass, soil carbon and water, and carbon dioxide fluxes with chambers. Long-term impacts of environment on ecological condition will be assessed by evaluating changes in plant species composition inside and outside livestock exclosures and evaluating changes in herbage production and rooting dynamics with short-term droughts applied with a rain-out shelter. Fundamental life history, autecolgical studies will be initiated to quantify role that varying abiotic and biotic factors play in regulating the rate and extent of invasion and control of noxious weeds. Fundamental understandings of important ecological processes will be researched, developed, expanded, and ultimately incorporated into rangeland restoration technologies. The potential role of planted forages will be studied by monitoring herbage growth dynamics, cattle diets, & weight gains. Late winter, early spring, and late spring calving seasons will be evaluated for their effect on biologic and economic measures of rangeland beef production. In vitro gas production techniques will be used to evaluate seasonal variations in forage quality and results will be evaluated for their ability to accurately predict performance of grazing cattle.

Progress 10/01/03 to 09/30/08

Outputs
Number of new CRADAs and MTAs: Number of active CRADAs and MTAs: Number of invention disclosures submitted: Number of patent applications filed: Number of U.S. patents granted: Number of new commercial licenses granted: Number of web sites managed: Number of non-peer reviewed presentations and proceedings: 9 Number of newspaper articles and other presentations for non-science audiences: 4

Impacts
Quantitative trait loci (QTL) affecting composition and healthfulness of beef: Consumers of beef want a palatable and healthful product at a reasonable price. They are increasingly concerned about relative levels of saturated and unsaturated fats in their diet. Genetically modifying lipid profiles can help cattle producers produce beef that more consistently meet consumers' expectations. We conducted a whole-genome scan in a Wagyu x Limousin population and identified seven QTL on five chromosomes involved in lipid metabolism, beef tenderness, and beef flavor. These QTL were independent of genes encoding major enzymes involved in fatty acid metabolism. The results guide future research to provide a richer understanding of genetic mechanisms controlling palatability and healthfulness of beef and may ultimately lead to tools for producing beef of greater value to consumers. (NP 101 Program Component IV - Genetic Improvement, Problem Area - Develop Breeding Objective) Traits used to identify replacement heifers and feeding levels provided during their postweaning development may affect efficiency of profitability of beef production. We provide evidence that feeding less than the currently recommended amount of energy after weaning may be a feasible option for producers to consider in developing replacement heifers. The feed restriction applied in this study resulted in a 27% reduction in harvested feed used during the 140-d post weaning development period and improved efficiency of gain. This improvement appeared to persist throughout the subsequent grazing period. Although a 5% reduction in pregnancy rate was observed in restricted heifers, harvested feed requirements per pregnant heifer were reduced by 22% during the 140-d development period, potentially reducing cost associated with development of replacement heifers. The effect of this potential savings on profitability of a beef production enterprise depends on disparity of market values associated with differences in numbers of heifer calves retained and lighter BW of open heifers. (NP 101 Program Component VIII - Nutrient Intake and Utilization, Problem Area - Interactions Affecting Reproduction)

Publications

• Waterman, R.C., Grings, E.E., Geary, T.W., Roberts, A.J., Alexander, L.J., MacNeil, M.D. 2007. Influence of seasonal forage quality on glucose kinetics of young beef cows. Journal of Animal Science 85:2582-2595. doi 10:2527/jas.2007-0023.
• Waterman, R.C., Loest, C.A., Bryant, W.D., Petersen, M.K. 2007. Supplemental methionine and urea for gestating beef cows consuming low quality forage diets. Journal of Animal Science online doi:10.2527/jas.2006-425. J. Anim Sci. 85:731-736.
• MacNeil, M.D., Leesburg, V.L., Mott, T.B. 2007. Validating the breeding value for maternal preweaning gain in beef cattle with measured milk production. South African Journal of Animal Science 36(Issue 5 Supple. 1):1-5.
• Merrill, M.L., Ansotegui, R.P., Burns, P.D., MacNeil, M.D., Geary, T.W. 2007. Effects of flunixin meglumine and transportation on pregnancy in beef cows. Journal of Animal Science 85:1547-1554.
• Perry, G.A., Smith, M.F., Roberts, A.J., MacNeil, M.D., Geary, T.W. 2007. Relationship between size of ovulatory follicle and pregnancy success in beef heifers. Journal of Animal Science 85:684-689.
• Roberts, A.J., Paisley, S.I., Geary, T.W., Grings, E.E., Waterman, R.C., MacNeil, M.D. 2007. Effects of restricted feeding of beef heifers during the postweaning period on growth, efficiency and ultrasound carcass characteristics. Journal of Animal Science 85:2740-2745.
• Tauck, S.A., Berardinelli, J.G., Geary, T.W., Johnson, N.J. 2006. Resumption of postpartum luteal function of primiparous, suckled beef cows exposed continuously to bull urine. Journal of Animal Science 84:2708-2713.
• Alexander, L.J., Juneja, B., Fahrenkrug, S. 2006. Isolation and radiation hybrid mapping of 213 porcine microsatellites. Animal Genetics 37(6):596-597.
• Alexander, L.J., Geary, T.W., Snelling, W.M., MacNeil, M.D. 2007. Quantitative trait loci with additive effect on growth and carcass traits in a Wagyu- Limousin F*2 population. Animal Genetics 38:413-416.
• Lamb, G.C., Larson, J.E., Geary, T.W., Stevenson, J.S., Johnson, S.K., Day, M.L., Kesler, D.J., Dejarnette, J.M., Landblom, D.G., Ansotegui, R.P. 2006. Synchronization of estrus and artificial insemination in replacement beef heifers using gonadotropin-releasing hormone, prostaglandin F2, and progesterone. Journal of Animal Science 84(11):3000-3009.
• MacNeil, M.D., Matjuda, E. 2007. Breeding objectives for Angus and Charolais specialized sire lines for use in the emerging sector of South African beef production. South African Journal of Animal Science 37(1):1-10.
• MacNeil, M.D., Cronin, M.A., Blackburn, H.D., Richards, C.M., Lockwood, D.R., Kantanen, J., Alexander, L.J. 2007. Genetic relationships between feral cattle from Chirikof Island, Alaska, and other breeds. Animal Genetics 38:193-197.
• Vonnahme, K.A., Zhu, M.J., Borowicz, P.B., Geary, T.W., Hess, B.W., Reynolds, L.P., Caton, J.S., Means, W.J., Ford, S.P. 2007. Effect of early gestational undernutrition on angiogenic factor expression and vascularity in the bovine placentome. Journal of Animal Science doi 10:2527/jas.2006-805.

Progress 01/01/06 to 12/31/06

Outputs
Heritability of follicle size and its genetic correlation with fertility: Sustained reproductive success is the most important determinant of efficient and profitable beef production. However, a lack of identified highly heritable traits that are closely correlated with fertility limits opportunity for genetic improvement of efficiency and profitability. Previous research has identified size of the ovulatory follicle as being temporally associated with conception and/or establishment of pregnancy. However, there has been no previous attempt to estimate the degree to which genetic effects control neither variation in follicle size nor the magnitude of its relationship with pregnancy rate. Thus, objectives of this work were to estimate heritability of follicle size and to assess its usefulness as an indicator trait associated with reproductive success in beef cattle. Results indicate heritability of size of the ovulatory follicle is greater than the heritability of pregnancy rate. However, owing to a very low genetic correlation of follicle size with pregnancy rate its greatest usefulness in genetic selection is as an ancillary trait. (NP 101 Program Component - Reproductive Efficiency and Genetic Improvement). Gene expression affecting establishment of estrous cycles by postpartum cows: Microarrays were used to evaluate gene expression profiles in anterior pituitary glands collected from four anestrous and four cycling postpartum beef cows. Each sample was hybridized to an individual microarray containing 24,027 total probe sets including 23,080 bovine gene transcripts. Thirty-four transcripts were differentially expressed in pituitaries from cycling cows and anestrous cows. Twenty of these transcripts share some homology with human proteins and 10 are previously uncharacterized. Although further study is required to confirm the role of these genes in the transition from anestrous to cycling status, results identify potentially novel mechanisms regulating reproductive function. (NP 101 Program Component - Reproductive Efficiency)

Impacts
Research provides detailed findings that serve to enhance rangeland based beef cattle productivity by improving longevity of cow production, cow reproductive success, and off-spring suitability in meeting consumer expectations.

Publications

• MacNeil, M.D., Geary, T.W., Perry, G.W., Roberts, A.J., Alexander, L.J. 2006. Genetic partitioning of variation in ovulatory follicle size and probability of pregnancy. Journal of Animal Science 84:1646-1650.
• MacNeil, M.D., Mott, T.B. 2006. Genetic analysis of gain from birth to weaning, milk production and udder conformation in line 1 hereford cattle. Journal of Animal Science 84:1639-1645.
• Walker, R.S., Enns, R.M., Geary, T.W., Wamsley, N.W., Mortimer, R.G., Lashell, B.A., Zalesky, D.D. 2005. Evaluation gonadotropin-releasing hormone at fixedtime ai in beef heifers synchronized using a modified co-synch plus cidr protocol. Professional Animal Scientist 21:449-454.
• Larson, J.E., Lamb, G.C., Stevenson, J.S., Johnson, S.K., Day, M.L., Geary, T.W., Kesler, D.J., Dejarnette, J.M., Schrick, F.N., Arseneau, J.D. 2006. Synchronization of estrus in suckled beef cows before detected estrus and (or) timed artificial insemination using gonadotropin-releasing hormone (gnrh), prostaglandin f2a (pg), and progesterone (cidr). Journal of Animal Science 84:332-342.
• Kealey, C.G., MacNeil, M.D., Tess, M.W., Geary, T.W., Bellows, R.A. 2006. Genetic parameter estimates for scrotal circumference and semen characteristics of yearling line 1 hereford bulls. Journal of Animal Science 84:283-290.
• Geary, T.W., Grings, E.E., MacNeil, M.D., De Avila, D.M., Reeves, J.J. 2006. Use of recombinant gonadotropin releasing hormone antigens for immunosterilization of beef heifers. Journal of Animal Science 84:343-350.
• Cronin, M.D., MacNeil, M.D., Patton, J.C. 2006. Mitochondrial dna and microsatellite dna variation in domestic reindeer (rangifer tarandus tarandus) and relationships with wild caribou (r. t. granti, r. t. groenlandicus, r. t. caribou). Journal of Heredity, doi:10.1093/jhered/es1012.

Progress 01/01/05 to 12/31/05

Outputs
Reduced shedding of E. coli O157:H7 would be useful in controlling contamination of meat. Seventy one cows were vaccinated approximately 30 days before parturition with an experimental vaccine and then co-mingled with 66 non-vaccinated control cows. Serum and fecal samples were collected from cows at vaccination and approximately 14 d postpartum. Serum and fecal samples were collected from calves at approximately 14 and 60 d postpartum. Vaccination of cows markedly increased antibody titers against E. coli O157:H7 in both cows and calves. However, differences between treatments in shedding of E. coli O157:H7 were not detected in calves at approximately 60 d of age as less than 5% of calves were shedding. Results indicate efficacy of vaccinating the gestating cow against E. coli O157:H7 in increasing antibody titers of both cow and suckling calf. (NP 101 Program Component - Product Quality (Pre-Harvest)). A project has been initiated to determine changes muscle satellite cell proliferation and fusion in response to compounds in growth promoting implants. Other: Tissues were collected from animals related to L1 Dominette 01449, the base DNA source for the bovine genome sequence. Seventy three tissues were collected from her 10-mo old heifer calf. Sixty three tissues were collected from her fetus at approximately 6-mo of gestation. Mammary, skin, gravid uterus and ovarian tissues were collected from the 01449 and testis was collected from her sire. Material transfer agreements with Genome Canada, University of Alberta, and Express Genomics have resulted in RNA being sent from our laboratory to others for construction and sequencing of 21 cDNA libraries. (NP 101 Program Component - Genomic Tools).

Impacts
Research provides detailed findings that serve to enhance rangeland based beef cattle productivity by improving longevity of cow production, cow reproductive success, and off-spring suitability in meeting consumer expectations.

Publications

• Perry, G.A., Smith, M.F., Lucy, M.C., Green, J.A., Parks, T.E., Macneil, M.D., Roberts, A.J., Geary, T.W. 2005. Relationship between follicle size at insemination and pregancy success in beef cattle. Proceedings of the National Academy of Sciences v. 102. no. 14. 5268-5273.
• Macneil, M.D. 2005. Genetic evaluation of the ratio of calf weaning weight to cow weight. Journal of Animal Science 83:794-802.
• Fahrenkrug, S., Wagner, M., Alexander, L.J., Morrison, L.Y. 2005. Radiation hybrid mapping of 373 previously unreported porcine microsatellites. Animal Genetics 36:76-86.
• Mickelson, J.R., Wagner, M.L., Goh, G., Wu, J.T., Morrison, L.Y., Alexander, L.J., Raudsepp, T., Skow, L.C., Chowdhary, B.P., Swinburne, J.E. 2004. Thirty-five new equine microsatellite loci assigned to the genetic linkage and radiation hybrid maps. Animal Genetics 35:481-484.
• Wagner, M.L., Goh, G., Wu, J.T., Morrison, L.Y., Alexander, L.J., Raudsepp, T., Skow, L.C., Chowdhary, B.P., Mickelson, J.R. 2004. Sixty-seven new equine microsatellite loci assigned to the radiation hybrid map. Animal Genetics 35:484-486.
• Cronin, M.W., Macneil, M.D., Patton, J.C. 2005. Variation in mitochondrial dna and microsatellite dna in caribou (rangifer tarandus) in north america. Journal of Mammalogy 86:495-505.
• Roberts, A.J., Klindt, J.M., Jenkins, T.G. 2005. Effects of varying energy intake and sire breed on duration of postpartum anestrus, insulin like growth factor-1, and growth hormone in mature crossbred cows. Journal of Animal Science 83(7):1705-1714.
• Funston, R.N., Lipsey, R.J., Geary, T.W., Roberts, A.J. 2005. Effect of administration of human chorionic gonadotropin after artificial insemination on concentrations of progesterone and conception rates in beef heifers. Journal of Animal Science. 83:1403-1405.
• MacNeil, M.D. Genetic evaluation of an index of birth weight and yearling weight to improve efficiency of beef production. Journal of Animal Science. 2003. 81:2425-2433

Progress 01/01/04 to 12/31/04

Outputs
Frequent clipping data from a series of primary productive studies were used to develop a proactive drought management strategy that assists rangeland agriculturalists (i.e. graziers) in managing rangeland based resources during periods of moderate to severe drought. Research established that 1) perennial grass production in much of the Northern Great Plains is tied closely to spring time precipitation and loosely tied to fall precipitation, and as such 2) about 90% of perennial grass production is normally completed by July 1. This is largely because summer precipitation is very limited in this region. Thus, ranchers in this region can assess, with some confidence, their annual forage production by July 1, thereby giving them an opportunity to respond to drought conditions long before they run entirely out of forage. Concerns have arisen about the potential varied effects of grazing strategies on plant community composition and standing crop. Knowledge of community response to grazing strategies is required for producers, land-managing agencies, and scientists to sustain productive rangeland resources for desired products. USDA-ARS, Miles City, MT, assessed community response to 7 grazing strategies by measuring standing crop of plant functional groups 1 year before and after 6 years of grazing treatments. Data have been presented to producers and college students and are scheduled to be presented at a scientific meeting in January 2004 that indicate grazing strategies are secondary to weather for impacting plant communities on claypan sites. Rapid and inexpensive determination of biological value of rangeland forage is important for livestock producers to efficiently use forage resources. USDA-ARS, Miles City, MT, developed an equation to predict percent nitrogen in standing.

Impacts
Research provides detailed findings that serve to enhance rangeland based beef cattle productivity by improving longevity of cow production, cow reproductive success, and off-spring suitability in meeting consumer expectations.

Publications

• Haferkamp, M.R., Macneil, M.D., Grings, E.E., Heitschmidt, R.K., Klement, K.D. 2004. Heifer production on rangeland and cool-season forages in the northern great plains. Agronomy Abstracts #508. On CD only.
• Haferkamp, M.R., Macneil, M.D., Grings, E.E. 2004. Predicting quality of forage from northern great plains range sites. Society for Range Management Meeting Abstracts #124. CD Only.
• HEITSCHMIDT, R.K., KLEMENT, K.D., KRUSE, R.E. DROUGHT MANAGEMENT - DO YOU HAVE TO RUN OUT OF FORAGE BEFORE MANAGING?. SOCIETY FOR RANGE MANAGEMENT MEETING ABSTRACTS. 2004. ABSTRACT #138.
• Heitschmidt, R.K., Vermeire, L.T., Grings, E.E. 2004. Is rangeland agriculture sustainable?. Journal of Animal Science 82(E. Suppl.):E138-E146.
• HEITSCHMIDT, R.K., HAFERKAMP, M.R., KLEMENT, K.D. GRAZING AND DROUGHT: EFFECTS ON QUANTITY OF FORAGE PRODUCED. SOCIETY FOR RANGE MANAGEMENT MEETING ABSTRACTS. 2003. ABSTRACT #107.
• Kruse, R.E., Tess, M.W., Grings, E.E., Heitschmidt, R.K., Phillips, W.A., Mayeux Jr, H.S. 2004. Evaluation of beef cattle operations utilizing different seasons of calving, weaning stratigies, post-weaning management, and retained ownership. Western Section of Animal Science Proceedings 55:122-125.
• Kruse, R.E., Tess, M.W., Grings, E.E., Short, R.E., Heitschmidt, R.K., Phillips, W.A., Mayeux Jr, H.S. 2004. Evaluation of beef cattle operations utilizing different seasons of calving, weaning stratigies, post-weaning management, and retained ownership. Western Section of Animal Science Proceedings 55:122-125.
• Mcadoo, J.K., Vermeire, L.T., Gilgert, W. 2004. The other grazers. Rangelands. 26(3) 30-37
• Mitchell, R., Vogel, K.P., Schmer, M.R., Vermeire, L.T. 2004. The medical approach to grassland assessment. Society for Range Management Meeting Abstracts. #259.
• ROSE, J., VERMEIRE, L.T., WESTER, D.B. ESTIMATING STANDING CROP WITH VISUAL OBSTRUCTION IN THE NORTHERN PLAINS. SOCIETY FOR RANGE MANAGEMENT MEETING ABSTRACTS. NO. 309. 2004.
• Rose, J.L., Vermeire, L.T., Wester, D.B. 2004. Effects of summer burning and stocking rate in the northern great plains. Research Highlights - 2004 Noxious Brush and Weed Control; Range, Wildlife, and Fisheries Management 35:26. Texas Tech University.
• VERMEIRE, L.T., HEITSCHMIDT, R.K., HAFERKAMP, M.R. NORTHERN PRAIRIE RESPONSE AFTER 6-YEAR EXPOSURE TO SEVEN GRAZING PRACTICES. SOCIETY FOR RANGE MANAGEMENT MEETING ABSTRACTS. No. 373. 2004.
• Vermeire, L.T., Heitschmidt, R.K., Johnson, P.S., Sowell, B.F. 2004. The prairie dog story: do we have it right?. Bioscience 54(7)689-695. Vermeire, L.T., Mitchell, R., Fuhlendorf, S.D., Gillen, R.L. 2004. Patch burning effects on forage utilization and grazing distribution. Journal of Range Management 57:248-252.
• Blummel, M., Grings, E.E., Haferkamp, M.R. 2004. Fermentation profiles and degradability measurements in extrusa diet samples collected from bromesuppressed and undisturbed pastures and their relationship to weight gain of steers. Canadian Journal of Animal Science 84(1):105-111.
• FOX, W.E., HEITSCHMIDT, R.K., JOYCE, L. SUSTAINABLE RANGELANDS ROUNDTABLE (SRR) CRITERION: CONSERVATION AND MAINTENANCE OF PLANT AND ANIMAL RESOURCES ON RANGELANDS. INTERNATIONAL RANGELAND CONGRESS. 2003. p. 1955-1957.
• GILMANOV, T.G., TIESZEN, L.L., WYLIE, B.K., FLANAGAN, L.B., FRANK, A.B., HAFERKAMP, M.R., MEYERS, T.P., AND MORGAN, J.A. 2004. TOWARDS SCALING-UP TOWER CO2 FLUX MEASUREMENTS IN GRASSLANDS OF THE NORTHERN GREAT PLAINS: PHENOMENOLOLGICAL MODELING USING FLUX PARTITIONING, VEGETATION INDICES AND GEOGRAPHIC INFORMATION SYSTEM (GIS). SOCIETY FOR RANGE MANAGEMENT MEETING ABSTRACTS #112.
• Grings, E.E., Short, R.E., Haferkamp, M.R., Heitschmidt, R.K. 2004. Late summer protein supplementation for yearling cattle in the northern great plains. Journal of Range Management 57:358-364.
• Grings, E.E., Short, R.E., Heitschmidt, R.K. 2004. Post-weaning production of steers from varying calving and weaning strategies. Western Section of Animal Science Proceedings 55:126-129.
• HAFERKAMP, M.R., MACNEIL, M.D. GRAZING EFFECTS ON CARBON DYNAMICS IN THE NORTHERN MIXED-GRASS PRAIRIE. ENVIRONMENTAL MANAGEMENT. 2004. Vol. 33. Suppl. 1. p. S462-S479.
• Vermeire, L.T., Mitchell, R., Fuhlendorf, S.D., Wester, D.B. 2004. Selective control of rangeland grasshoppers with prescribed fire. Journal Of Range Management v. 57. p. 29-33.

Progress 01/01/03 to 12/31/03

Outputs
Longevity of breeding stock has substantial impact on economic efficiency of beef production systems. In collaboration studies, phenotypic and genetic factors associated with differences in sustained reproductive success were identified. Cows having a genetic profile for size and milk consistent with nutritional resources were at less risk of being culled than those with greater genetic potential for production. Results of this research have important economic ramifications for beef producers and provide estimates of breeding values essential to mapping QTL for longevity. Reducing embryonic mortality may provide beef producers economically important benefits through increased pregnancy rates and production of calves that are older and therefore heavier at weaning. In a collaboration with Dr. Michael Smith, University of Missouri, Columbia and Fort Keogh Livestock and Range Research Laboratory, Miles City, MT; we observed increased early embryonic mortality associated following induced ovulation of small follicles with gonadotrophin releasing hormone. However, increased embryonic mortality was not associated with spontaneously ovulated small follicles suggesting that size of the ovulatory follicle may not be as important as adequate exposure of the reproductive tract to follicle phase events. This relationship may enhance understanding of the mechanisms controlling early embryonic mortality. Selecting germplasm best suited to a particular nutrient and management production system can lower the cost of production for beef producers. In a collaboration between Dr. Thomas Jenkins, U.S. Meat Animal Research Center, Clay Center, NE and Fort Keogh Livestock and Range Research Laboratory, Miles City, MT; we found circulating concentrations of insulin-like growth factor 1 and growth hormone may be indicative of energy balance of beef cows. This research has important implications in conditions where energy availability is restricted, but requires additional study before its general application. Modifying body composition through selection or management can help cattle producers and feeders produce beef that more consistently meets expectations of consumers. In a collaboration between Dr. Duane Keisler, University of Missouri, Columbia and Fort Keogh Livestock and Range Research Laboratory, Miles City, MT; we found circulating concentrations of leptin provide a strong indicator of fat content in live cattle. This relationship, if coupled with other indicators of composition, may facilitate appropriate feeding and marketing strategies for beef cattle. Inducing and synchronizing estrus of beef cows can increase the proportion of calves born early in the calving season and increase use of genetically superior sires. In collaborative studies, we evaluated strategies to make these technologies less costly and more effective. Results of this research indicate timed insemination coupled with an injection of gonadotrophin releasing hormone (GnRH) may enhance the efficacy of these technologies; and that less costly human chorionic gonadotrophin should not be substituted for GnRH in implementing these technologies.

Impacts
Research provides detailed findings that serve to enhance rangeland based beef cattle productivity by improving longevity of cow production, cow reproductive success, and off-spring suitability in meeting consumer expectations.

Publications

• MERRILL, M.L., ANSOTEGUI, R.P., WAMSLEY, N.E., BURNS, P.D., GEARY, T.W. EFFECTS OF FLUNIXIN MEGLUMINE ON EMBRYONIC LOSS IN STRESSED BEEF COWS. JOURNAL OF ANIMAL SCIENCE SUPPLEMENT ABSTRACT #140. 2003. v. 81(SUPPL. 1). p. 35.
• MERRILL, M.L., ANSOTEGUI, R.P., WAMSLEY, N.E., BURNS, P.D., GEARY, T.W. EFFECTS OF FLUNIXIN MEGLUMINE ON EMBRYONIC LOSS IN STRESSED BEEF COWS. WESTERN SECTION OF ANIMAL SCIENCE PROCEEDINGS. 2003. v. 54. p. 53-55.
• FUNSTON, R.N., GEARY, T.W., ANSOTEGUI, R.P., LIPSEY, R.J., PATERSON, J.A. SUPPLEMENTATION WITH WHOLE SUNFLOWER SEEDS BEFORE ARTIFICIAL INSEMINATION IN BEEF HEIFERS. PROFESSIONAL ANIMAL SCIENTIST. 2002. 18:254-257.
• FUNSTON, R.N., PATERSON, J.A., WILLIAMS, K.E., ROBERTS, A.J. EFFECT OF BODY CONDITION, INITIAL WEIGHT, AND IMPLANT ON FEEDLOT AND CARCASS CHARACTERISTICS OF CULL COWS. PROFESSIONAL ANIMAL SCIENTIST. 2003. V. 19. P. 233-238.
• MACNEIL, M.D., MILLER, R.K., GROSZ, M.D. GENOME-WIDE SCAN FOR QUANTITATIVE TRAIT LOCI AFFECTING PALATABILITY OF BEEF. PLANT AND ANIMAL GENOME CONFERENCE PROCEEDINGS. 2003. ABSTRACT #218.
• MACNEIL, M.D. GENETIC TRENDS RESULTING FROM SELECTION BASED ON AN INDEX OF BIRTH WEIGHT AND YEARLING WEIGHT. JOURNAL OF ANIMAL SCIENCE SUPPLEMENT ABSTRACT #343. 2003. V. 81(SUPPL. 1). P. 86.
• MACNEIL, M.D., GROSZ, M.D. GENOME-WIDE SCANS FOR QTL AFFECTING CARCASS TRAITS IN HEREFORD X COMPOSITE DOUBLE BACKCROSS POPULATIONS. JOURNAL OF ANIMAL SCIENCE. 2002. V. 80. P. 2316-2324.
• ROGERS, P.L., GASKINS, C.T., JOHNSON, K.A., MACNEIL, M.D. RISK FACTORS ASSOCIATED WITH CULLING FEMALES IN A COMPOSITE BEEF HERD. JOURNAL OF ANIMAL SCIENCE SUPPLEMENT ABSTRACT #138. 2003. V. 81(SUPPL. 1). P. 34.
• ROGERS, P.L., GASKINS, C.T., JOHNSON, K.A., MACNEIL, M.D. RISK FACTORS ASSOCIATED WITH CULLING FEMALES IN A COMPOSITE BEEF HERD. WESTERN SECTION OF ANIMAL SCIENCE PROCEEDINGS. 2003. V, 54. P. 68-71.
• ROBERTS, A.J., JENKINS, T.G. ASSOCIATIONS AMONG CIRCULATING CONCENTRATIONS OF IGF-1 AND GH DURING THE POSTPARTUM PERIOD WITH RESUMPTION OF ESTRUS, CALF WEIGHTS, AND MILK PRODUCTION IN MATURE CROSSBRED COWS FED VARYING LEVELS OF ENERGY INTAKE. JOURNAL OF ANIMAL SCIENCE SUPPLEMENT ABSTRACT #401. 2003. v. 81(SUPPL. 1). p. 101.
• ROBERTS, A.J., JENKINS, T.G. ASSOCIATIONS AMONG CIRCULATING CONCENTRATIONS OF IGF-1 AND GH DURING THE POSTPARTUM PERIOD WITH RESUMPTION OF ESTRUS, CALF WEIGHTS, AND MILK PRODUCTION IN MATURE CROSSBRED COWS FED VARYING LEVELS OF ENERGY INTAKE. WESTERN SECTION OF ANIMAL SCIENCE PROCEEDINGS. 2003. v. 54. p. 288-290.
• OLSON, J.L., ROBERTS, A.J., PATERSON, J.A., FUNSTON, R.N. EFFECT OF EXOGENOUS PROGESTERONE BEFORE CALF REMOVAL AND PROSTAGLANDIN F2ALPHA ON ESTROUS RESPONSE AND PREGNANCY RATES IN 3-YEAR-OLD BEEF COWS. JOURNAL OF ANIMAL SCIENCE SUPPLEMENT. 2003. v. 81(Suppl. 1). p. 186.
• FUNSTON, R.N., PATERSON, J.A., WILLIAMS, K.E., ROBERTS, A.J. FEEDING AND MARKETING CULL COWS. MONTANA NUTRITION CONFERENCE. 2002. p. 18-23.
• OLSON, J.L., ROBERTS, A.J., PATERSON, J.A., FUNSTON, R.N. EFFECT OF EXOGENOUS PROGESTERONE BEFORE CALF REMOVAL AND PROSTAGLANDIN F*2 ALPHA ON ESTROUS RESPONSE AND PREGNANCY RATES IN 3-YEAR-OLD BEEF COWS. WESTERN SECTION OF ANIMAL SCIENCE PROCEEDINGS. 2003. v. 54. p. 277-280.
• PERRY JR, G.A., SMITH, M.F., ROBERTS, A.J., MACNEIL, M.D., GEARY, T.W. EFFECT OF OVULATORY FOLLICLE SIZE AT TIME OF GNRH INJECTION ON PREOVULATORY SERUM CONCENTRATIONS OF ESTRADIOL IN BEEF COWS. SOCIETY FOR THE STUDY OF REPRODUCTION ANNUAL MEETING ABSTRACT #530. 2003. v. 68(1). p. 330.
• PERRY JR, G.A., SMITH, M.F., LUCY, M.C., ROBERTS, A.J., MACNEIL, M.D., GEARY, T.W. EFFECT OF OVULATORY FOLLICLE SIZE AT TIME OF GNRH INJECTION OR STANDING ESTRUS ON PREGNANCY RATES AND EMBRYONIC/FETAL MORTALITY IN BEEF CATTLE. JOURNAL OF ANIMAL SCIENCE SUPPLEMENT ABSTRACT #211. 2003. v. 81(SUPPL. 1). p. 52.
• PERRY JR, G.A., SMITH, M.F., LUCY, M.C., ROBERTS, A.J., MACNEIL, M.D., GEARY, T.W. EFFECT OF OVULATORY FOLLICLE SIZE AT TIME OF GNRH INJECTION OR STANDING ESTRUS ON PREGNANCY RATES AND EMBRYONIC/FETAL MORTALITY IN BEEF CATTLE. WESTERN SECTION OF ANIMAL SCIENCE PROCEEDINGS. 2003. v. 54. p. 281-284.
• FUNSTON, R.N., OLSON, J.L., LIPSEY, R.J., GEARY, T.W., ROBERTS, A.J. EFFECT OF HCG ADMINISTRATION APPROXIMATELY 5 D AFTER ARTIFICIAL NSEMINATION ON PROGESTERONE CONCENTRATIONS AND AI CONCEPTION RATES IN BEEF HEIFERS. JOURNAL OF ANIMAL SCIENCE SUPPLEMENT ABSTRACT #212. 2003. v. 81(Suppl. 1). p. 53.
• FUNSTON, R.N., OLSON, J.L., LIPSEY, R.J., GEARY, T.W., ROBERTS, A.J. EFFECT OF HCG ADMINISTRATION APPROXIMATELY 5 D AFTER ARTIFICIAL INSEMINATION ON PROGESTERONE CONCENTRATIONS AND AI CONCEPTION RATES IN BEEF HEIFERS. WESTERN SECTION OF ANIMAL SCIENCE PROCEEDINGS. 2003. v. 54. p. 251-253.
• GEARY, T.W. FERTILITY AND DISTRIBUTION OF ESTRUS AMONG COWS FOLLOWING PROSTAGLANDIN INDUCED EMBRYONIC/FETAL MORTALITY. JOURNAL OF ANIMAL SCIENCE SUPPLEMENT. Abstract #471. 2003. v. 81(Suppl. 1). p. 119.
• GEARY, T.W., SALVERSON, R.R., WHITTIER, J.C. SYNCHRONIZATION OF OVULATION USING GNRH OR HCG WITH THE CO-SYNCH PROTOCOL IN SUCKLED BEEF COWS. JOURNAL OF ANIMAL SCIENCE. 2001. v. 79. p. 2536-1541.
• GEARY, T.W., MCFADIN, E.L., MACNEIL, M.D., GRINGS, E.E., SHORT, R.E., FUNSTON, R.N., KEISLER, D.H. LEPTIN AS A PREDICTOR OF CARCASS COMPOSITION IN BEEF CATTLE. JOURNAL OF ANIMAL SCIENCE. 2003. v. 81. p. 1-8.
• GEARY, T.W. FERTILITY AND DISTRIBUTION OF ESTRUS AMONG COWS FOLLOWING PROSTAGLANDIN INDUCED EMBRYONIC/FETAL MORTALITY. WESTERN SECTION OF ANIMAL SCIENCE PROCEEDINGS. 2003. v. 54. p. 254-256.
• GEARY, T.W. MANAGEMENT OF YOUNG COWS FOR MAXIMUM REPRODUCTIVE PERFORMANCE. BEEF IMPROVEMENT FEDERATION PROCEEDINGS. 2003. p. 5-8.
• STANTON, T.L., WHITTIER, J.C., GEARY, T.W., KIMBERLING, C.V., JOHNSON, A.B. EFFECTS OF TRACE MINERAL SUPPLEMENTATION ON COW-CALF PERFORMANCE, REPRODUCTION, AND IMMUNE FUNCTION. PROFESSIONAL ANIMAL SCIENTIST. 2000. v. 16. p. 121-127.
• HALL, J.B., DEJARNETTE, J.M., WHITTIER, J.C., GEARY, T.W. TIMING OF INSEMINATION AND GNRH ON PREGNANCY RATES IN BEEF COWS IN A MODIFIED CO-SYNCH ESTROUS SYNCHRONIZATION SYSTEM. JOURNAL OF ANIMAL SCIENCE SUPPLEMENT ABSTRACT #206. 2003. v. 81(Suppl. 1). p. 51.
• HALL, J.B., DEJARNETTE, J.M., WHITTIER, J.C., GEARY, T.W. TIMING OF INSEMINATION AND GNRH ON PREGNANCY RATES IN BEEF COWS IN A MODIFIED CO-SYNCH ESTROUS SYNCHRONIZATION SYSTEM. WESTERN SECTION OF ANIMAL SCIENCE PROCEEDINGS. 2003. v. 54. p. 257-260.

Progress 01/01/02 to 12/31/02

Outputs
Pregnancy recognition failure and early embryonic mortality represent large economic losses to the beef cow-calf industry and may be dependent upon several factors including characteristics related to the developmental competence of the ovulatory follicle. Estrus and ovulation were synchronized in beef cows to evaluate the effects of follicle size and growth rate on pregnancy establishment and early embryonic mortality. This data coupled with preliminary data collected last year suggest that follicle size at the time of ovulation, growth rate, and prior cycling status all affected pregnancy establishment and maintenance. Current research will help identify whether improved genetic or management strategies can be developed that will increase pregnancy rates and early embryonic survival improve reproductive and economic efficiency in beef cattle. Because early and repeated pregnancy examinations have suggested a higher incidence of embryonic mortality than originally believed, we hypothesized that fertility of the subsequent estrus must be improved to allow for the relatively high pregnancy rates associated with short breeding seasons. Non-pregnant beef cows or cows that were 25, 30 or 35 days pregnant received an injection of prostaglandin to terminate pregnancies and synchronize estrous cycles. These cows were exposed to fertile bulls for a 34 to 44-day breeding season depending on when they received prostaglandin. The interval to estrus was similar for both non-pregnant and previously pregnant cows following the prostaglandin injection. Synchronized pregnancy rates for non-pregnant cows and cows receiving prostaglandin on day 25, 30 or 35 of gestation were 69%, 68%, 79%, and 86% respectively, indicating improved fertility among cows that lost pregnancies during the late embryonic to early fetal stages of gestation. Identifying the mechanism by which loss of early pregnancies (d 30-35 of gestation) ultimately improves fertility of the subsequent estrus may provide clues for improving overall herd fertility. Fertilization rates of beef cattle are reported to be greater than 93%, while single service pregnancy rates are generally around 70% suggesting that a number of embryos fail to establish pregnancies. This pregnancy failure is believed to be due primarily to inadequate signaling by the developing embryo of its presence in the uterus. Systemic progesterone concentrations have also been reported to be higher in pregnant cows than in non-pregnant cows during the early luteal phase after breeding. We hypothesized that administering human chorionic gonadotropin (hCG) to beef heifers approximately five days after breeding would elevate progesterone concentrations and increase pregnancy rates to artificial insemination. Approximately 540 heifers at two locations were used for this study. This data suggests that pregnancy rates can be increased in beef cattle by extending the interval from conception to maternal recognition of pregnancy, to which may improve an embryo's ability to signal its presence.

Impacts
Research will provide new understandings of factors affecting beef cattle reproductive success which in turn will help define the appropriateness of varying management strategies as they relate to nutrition, synchronized estrous, and early life identification and exploitation of the lifetime reproductive potential of beef cows.

Publications

• Funston, R.N., Ansotegui, R.P., Lipsey, R.J., Geary, T.W. 2002. Evaluation of melengestrol acetate/prostaglandin (MGA/PGF), Select Synch, and 7 d MGA/Select Synch estrous synchronization protocols in beef heifers. Proceedings of the Western Section American Society of Animal Science. 2001. 53:405-406.
• Geary, T.W., Grings, E.E., MacNeil, M.D., Keisler, D.H. 2002. Effects of feeding high linoleate safflower seeds prepartum on leptin concentration, weaning, and re-breeding performance of beef heifers. Proceedings of the Western Section American Society of Animal Science. 2002. 53:425-427.
• Perry, G.A., Geary, T.W., Lucy, M.C., Smith, M.F. 2002. Effect of follicle size at time of GnRH-induced ovulation on luteal function and fertility. Proceedings of the Western Section American Society of Animal Science. 2002. 53:45-48.
• Grings, E.E., Short, R.E., Geary, T.W., MacNeil, M.D. 2002. Heifer development within three seasons of calving. Proceedings of the Western Section American Society of Animal Science. 2002. 53:261-264.
• Funston, R.N., Ansotegui, R.P., Lipsey, R.J., Geary, T.W. 2002. Synchronization of estrus in beef heifers using either melengesterol acetate (MGA)/prostaglandin or MGA/Select Synch. Theriogenology. 2002. 57:1485-1491.
• Geary, T.W. 2002. Synchronizing estrus in beef cattle. In: Cow-Calf Management Guide & Cattle Producer=s Library. Cow-Calf Management Library CL405. Cooperative Extension System. 405:1-7.
• Geary, T.W., Grings, E.E., MacNeil, M.D., Keisler, D.H. 2002. Effects of feeding high linoleate Safflower seeds prepartum on leptin concentration, weaning, and re-breeding performance of beef heifers. Journal of Animal Science. 2002. 80(Suppl. 2):131-132.
• Funston, R.N., Ansotegui, R.P., Lipsey, R.J., Geary, T.W. 2002. Evaluation of melengesterol acetate/prostaglandin (MGA/PGF), Select Synch, and 7 d MGA/Select Synch estrous synchronization protocols in beef heifers. Journal of Animal Science. 2002. 80(Suppl. 2):128.
• Roberts, A.J., Jenkins, T.G. 2002. Effects of varying energy intake and sire breed on duration of postpartum anestrus, IGF-1,and GH in mature crossbred cows. Journal of Animal Science. 2002. 80(Suppl. 2):132.
• Roberts, A.J., Jenkins, T.G. 2002. Effects of varying energy intake and sire breed on duration of postpartum anestrus, IGF-1,and GH in mature crossbred cows. Western Section American Society of Animal Science. 2002. 53:454-456.
• Perry, G.A., Geary, T.W., Lucy, M.C., Smith, M.F. 2002. Effect of follicle size at time of GnRH-induced ovulation on luteal function and fertility. Journal of Animal Science. 2002. 80(Suppl. 2):114-115.
• Grings, E.E., Short, R.E., Geary, T.W., MacNeil, M.D. 2002. Heifer development within three seasons of calving. Journal of Animal Science. 2002. 80(Suppl. 2):120.
• McFadin, E.L., Geary, T.W., MacNeil, M.D., Keisler, D.H., Berg, E.P. 2002. Relationship between serum concentrations of leptin and carcass composition and quality in beef cattle and swine. Reciprocal Meat Conference Proceedings. 2002. Abstract.

Progress 01/01/01 to 12/31/01

Outputs
A. Most significant accomplishment in past year: Pregnancy recognition failure and early embryonic mortality represent large economic losses to the beef cow-calf industry and may be depen- dent upon several factors including characteristics related to the developmental competence of the ovulatory follicle. At USDA-ARS, Miles City, MT, estrus was synchronized in beef females, in collaboration with the University of Missouri, to evaluate the effects of follicle size and growth rate on pregnancy establishment and early embryonic mortality. This preliminary data suggests that follicle size at the time of ovulation, growth rate, and prior cycling status all affected pregnancy rates and embryonic survival. If further research confirms these findings, then management strategies can be developed that will increase pregnancy rates and early embryonic survival to result in huge economic improvements related to reproductive efficiency in beef cattle.

Impacts
These protocols facilitate use of desirable genetics for today's consumer driven market. Synchronization of estrus with natural service can increase weaning weights and pregnancy rates within a cowherd. These sterilization vaccines could save the beef industry millions of dollars in carcass quality, feedlot efficiency, morbidity, and mortality associated with pregnant or cyclic heifers.

Publications

• Osoegawa, K., Chung, L.S., Zhu, B., Gardner, J., Geary, T.W., Antczak, D., Rauch, G.J., Catanese, J.J., de Jong, P. 2001. Construction of new maize, bovine, equine and zebrafish BAC libraries. Available from: http://www.intl-pag.com/pag/9/abstracts. Plant & Animal Genome IX Conference Abstracts.
• Geary, T.W., Grings, E.E., MacNeil, M.D., Bellows, S.E., Bertrand, K.P., de Avila, D.M., Reeves, J.J. 2001. Use of recombinant GnRH antigens for immunosterilization of beef heifers. Journal of Animal Science. v. 79(Suppl.1):Abstract p. 117.
• Funston, R.N., Geary, T.W., Ansotegui, R.P., Lipsey, J.J., MacNeil, M.D., Paterson, J.A. 2001. Supplementation of whole sunflower seeds before AI in beef heifers. Journal of Animal Science. v. 79(Suppl.2):Abstract p. 132.
• Geary, T.W., Whittier, J.C., Mortimer, R.G., Young, J.W., Salverson, R.R. 2001. Synchronization of estrus in beef cows using GnRH and PGF with estrus AI or timed AI 72 h after PGF with or without a second GnRH injection. Journal of Animal Science. v. 79(Suppl.2):Abstract p. 131.
• Foster, H.A., Whittier, J.C., Burns, P.D., Bruemmer, J.E., Field, T.G., Geary, T.W. 2001. Half dose GnRH does not affect pregnancy rates with the CO-Synch synchronization protocol. Journal of Animal Science. v. 79(Suppl.2):Abstract p. 132.
• Foster, H.A., Whittier, J.C., Burns, P.D., Bruemmer, J.E., Baker, D.S., Engle, T.E., Field, T.G., Wailes, W.R., Geary, T.W. 2001. Use of bovine somatotropin in conjunction with CO-Synch and Select Synch protocols for synchronizing estrus and ovulation in beef cows. Journal of Animal Science. v. 79(Suppl.2):Abstract p. 123.
• Geary, T.W., McFadin-Buff, E.L., MacNeil, M.D., Funston, R.N., Short, R.E., Grings, E.E., Keisler, D.H. 2001. A possible role of the leptin assay in assessing carcass fat and composition in beef cattle. Journal of Animal Science. v. 79(Suppl.2):Abstract p. 125.
• Short, R.E., Grings, E.E., MacNeil, M.D. 2001. A model for determining risk of pine needle abortion in cattle calving at different times of the year. Journal of Animal Science. v. 79(Suppl.2):Abstract p. 118.
• Lucy, M.C., Billings, H.J., Butler, W.R., Ehnis, L.R., Fields, M.J., Kesler, D.J., Kinder, J.E., Mattos, R.C., Short, R.E., Thatcher, W.W., Wettemann, R.P., Yelich, J.V., Hafs, H.D. Efficacy of an intravaginal progesterone insert & an injection of PGF*2" for synchronizing estrus & shortening the interval to pregnancy in postpartum beef cows, peripubertal beef heifers, and dairy heifers. Journal of Animal Science. 2001. v.79. p.982-95
• Short, R.E., Grosz, M.D., MacNeil, M.D., Grings, E.E. Effects of muscularity on pelvic area and efficiency in Hereford, Limousin and Piedmontese F2 crossbred calves genotyped for the Piedmontese myostatin allele. European Association of Animal Production. 2000. p. 9.
• Funston, R.N., Geary, T.W., Ansotegui, R.P., Lipsey, J.J., MacNeil, M.D., Paterson, J.A. 2001. Supplementation of whole sunflower seeds before AI in beef heifers. Proceedings of the Western Section American Society of Animal Science. v. 52. p. 381-383.
• Geary, T.W., Whittier, J.C., Mortimer, R.G., Young, J.W., Salverson, R.R. 2001. Synchronization of estrus in beef cows using GnRH and PGF with estrus AI or timed AI 72 h after PGF with or without a second GnRH injection. Proceedings of the Western Section American Society of Animal Science. v. 52. p. 369-371.
• Geary, T.W., McFadin-Buff, E.L., MacNeil, M.D., Funston, R.N., Short, R.E., Grings, E.E., Keisler, D.H. 2001. A possible role of the leptin assay in assessing carcass fat and composition in beef cattle. Proceedings of the Western Section American Society of Animal Science. v. 52. p. 253-255.
• Foster, H.A., Whittier, J.C., Burns, P.D., Bruemmer, J.E., Field, T.G., Geary, T.W. 2001. Half dose GnRH does not affect pregnancy rates with the CO-Synch estrus synchronization protocol. Proceedings of the Western Section American Society of Animal Science. v. 52. p. 374-376.
• Foster, H.A., Whittier, J.C., Burns, P.D., Bruemmer, J.E., Baker, D.S., Engle, T.E., Field, T.G., Wailes, W.R., Anderson, D.C., Boss, D.L., Geary, T.W. 2001. Use of bovine somatotropin in conjunction with the CO-Synch and Select Synch protocols for synchronizing estrus and ovulation in beef cows. Proceedings of the Western Section American Society of Animal Science. v. 52. p. 66-69.
• Short, R.E., Grings, E.E., MacNeil, M.D. 2001. A model for determining risk of pine needle abortion in cattle calving at different times of the year. Proceedings of the Western Section American Society of Animal Science. v. 52. p. 174-176.
• Geary, T.W., Whittier, J.C., Hallford, D.M., MacNeil, M.D. Calf removal improves conception rates to the Ovsynch and CO-Synch protocols. Journal of Animal Science. 2001. v. 79. p. 1-4.
• Bellows, R.A., Grings, E.E., Simms, D.D., Geary T.W., Bergman, J.W. Effects of feeding supplemental fat during gestation to first-calf beef heifers. Professional Animal Scientist. 2001. v. 17. p. 81-89.
• Rule, D.C., Rule, J.M., Short, R.E., Grings, E.E., MacNeil, M.D. Genotype effects on cholesterol and fatty acids in longissimus and semitendinosus muscles from Hereford, Limousin, and Piedmontese F*2 crossbred cattle at slaughter. Journal of Animal Science. 2001. v. 79(Suppl. 2):Abstract p. 125.

Progress 01/01/00 to 12/31/00

Outputs
Improvements in synchronization of estrus and ovulation are needed to facilitate the use of superior genetics through artificial insemination (AI) in the beef industry. Producers who use natural service also may benefit with estrous synchronization programs that induce estrous cycles in anestrous cows. Three synchronization studies were conducted to evaluate efficacy of protocols in commercial cowherds. Study 1 included the addition of timed AI (TAI) with or without an additional injection of GnRH 3 days after prostaglandin (PGF) and 10 days after GnRH for cows not exhibiting estrus. Timed AI pregnancy rate of non-responding cows that received the second GnRH injection (34%) were not different from cows that did not receive the second GnRH injection (29%). Study 2 evaluated reproductive performance and calf productivity by synchronizing estrus for natural service using GnRH followed 1 wk later with an injection of PGF. Pregnancy rates were 9% higher for cows that received synchronization prior to the 50-day breeding season in one herd. Study 3 evaluated reduced dosages of GnRH for synchronizing estrus and ovulation in cyclic and anestrous beef cows. Cows from 5 locations in Colorado and Montana were artificially inseminated after receiving either the GnRH/PGF estrous synchronization protocol or the GnRH/PGF/GnRH+TAI ovulation synchronization protocol. Reducing the dosage of the first GnRH injection from 100 mcg (2 cc) to 50 mcg (1 cc) had no effect on synchronization rates, but tended to decrease the conception rate of cows that were bred by estrus (GnRH/PGF). Use of 50 mcg of GnRH with the GnRH/PGF/GnRH+TAI protocol did not affect pregnancy rates. This data suggests that producers probably should not reduce the dosage of GnRH intentionally, but that poor injection techniques should still produce the desire effects. Immunological spaying was evaluated in 47 crossbred heifers. Heifers were immunized against either carrier protein (control) or one of 3 recombinant GnRH vaccines at approximately 8 months of age. Estrous cycles were eliminated or prevented in 34/36 heifers that received the sterilization vaccines whereas 11/11 control heifers entered puberty and exhibited regular estrous cycles during the 20 weeks following immunization. Two studies were designed to evaluate the effects of feeding fat on pregnancy rates of replacement heifers. Diets that were high in fat were fed to heifers for 0, 33, or 60 days prior to a synchronized AI breeding season, or 0 or 162 days prior to the start of a natural breeding season. None of the high fat diets had an effect on pregnancy rates, but a higher percentage of heifers that received the high fat diet for 162 days had reached puberty by the start of the breeding season. Feeding diets high in fat did not appear to benefit replacement heifers that were in moderate body condition.

Impacts
These protocols facilitate use of desirable genetics for today's consumer driven market. Synchronization of estrus with natural service can increase weaning weights and pregnancy rates within a cowherd. These sterilization vaccines could save the beef industry millions of dollars in carcass quality, feedlot efficiency, morbidity, and mortality associated with pregnant or cyclic heifers.

Publications

• Funston, R.N., Geary, T.W. Rebreeding the first-calf heifer. Cow- Calf Management Guide and Cattle Producer's Library. 1999. p. 413.1-4.
• Geary, T.W. Tips to improve AI pregnancy rates. Cow-Calf Management Guide. 2000. p. 406.1-5.
• Geary, T.W. Use of reproductive tract scoring in range beef heifers. Cow-Calf Management Guide. 2000. p. 442.1-4.
• Geary, T.W., Downing, E.R., Bruemmer, J.E., Whittier, J.C. Ovarian and estrous response of suckled beef cows to the select synch estrous synchronization protocol. Professional Animal Scientist. 2000. v. 16. p. 1-5.
• Lammoglia, M.A., Bellows, R.A., Grings, E.E., Bergman, J.W., Bellows, S.E., Short, R.E., Hallford, D.M., Randel, R.D. Effects of dietary fat and sire breed on puberty, weight, and reproductive traits of F1 beef heifers. Journal of Animal Science. 2000. v. 78. p. 2244-2252.
• Stanton, T.L., Whittier, J.C., Geary, T.W., Kimberling, C.V., Johnson, A.B. Effects of trace mineral supplementation on cow-calf performance, reproduction, and immune function. Professional Animal Scientist. 2000. v. 16(2). p. 121-127.
• Bellows, R.A. Some effects of feeding supplemental fat to beef cattle. Proceedings of Montana Nutrition Conference. 2000. p. 41-48.
• Bellows, R.A. Some effects of feeding supplemental fat to beef cattle. Proceedings of Bovine Connection. 1999. p. 25-31.
• Bellows, R.A. Some effects of feeding supplemental fat to beef cattle. Proceedings of Range Beef Cow Symposium. 1999. p. 81-87.
• Bellows, R.A. Reproduction research affecting beef cow productivity. University of Missouri Agricultural Experiment Station Publication. 2000. p. 1-18.
• Bellows, R.A., Simms, D.D., Grings, E.E., Phelps, D.A., Bellows, S.E., Bellows, N.R., Short, R.E., Funston, R.N., Geary, T.W. Effects of feeding supplemental fat during gestation on reproduction in first-calf beef heifers. Research Update for Fort Keogh Livestock and Range Research Laboratory. 1999. p. D.11.1-2.
• Funston, R.N., Geary, T.W. Rebreeding the first calf heifer. Research Update for Fort Keogh Livestock and Range Research Laboratory. 1999. p. C.11.1-5.
• Geary, T.W., Funston, R.N. Development of new estrous and ovulation synchronization protocols for use in beef cows and heifers. Research Update for Fort Keogh Livestock and Range Research Laboratory. 1999. p. C.8.1-2.
• Funston, R.N., Geary, T.W. Optimizing reproductive performance: Management practices can assist in shortening the postpartum interval. Montana Farmer-Stockman. April 2000. p. 10-13.
• Geary, T.W. Synchronization of estrus: Ovulation protocols that work! Beef Questions and Answers. 2000. v. 5(4). p. 3-6.
• Geary, T.W. Six ways to synchronize. Simtalk. 2000. v. 8(2). p. 28-32.
• Geary, T.W., Funston, R.N., Grings, E.E., Bellows, R.A., Short, R.E. Profitability of estrous synchronization with natural service. Research Update for Fort Keogh Livestock and Range Research Laboratory. 1999. p. C.7.1-2.
• Whittier, J.C., Geary, T.W. Frequently asked questions about synchronizing estrus and ovulation in beef cattle with Gnrh. Proceedings of Iowa Cooperative Extension CHIPS Beef Breeding Management Program. 2000. p. 1-14.
• Lammoglia, M.A., Bellows, R.A. Further studies on the effect of feeding fat to pregnant heifers on cold tolerance of their newborn calves. Research Update for Fort Keogh Livestock and Range Research Laboratory. 1999. p. D.10.1-2.
• Whittier, J.C., Geary, T.W. Frequently asked questions about synchronizing estrus and ovulation in beef cattle with Gnrh. Virginia Cooperative Extension Publications: Current Methods in Reproduction. 2000. p. 51-64.
• Bellows, R.A., Grings, E.E., Phelps, D.A., Bellows, S.E., Geary, T.W., Simms, D.D. Feeding supplemental fat to mature cows. Journal of Animal Science. 2000. v. 78(Suppl. 2): Abstract p. 228.
• Funston, R.N., Ansotegui, R.P., Thompson, B.D., Lipsey, R.J., Ropp, M.D., Geary, T.W. Evaluation of the Melengesterol Acetate/prostaglandin (MGA/PGF) and MGA/select synch estrous synchronization protocols in beef heifers. Proceedings of Western Section of Animal Science. 2000. v. 51. p. 140-142.
• Funston, R.N., Ansotegui, R.P., Thompson, B.D., Lipsey, J.J. Ropp, M.D., Geary, T.W. Evaluation of the Melengesterol Acetate/prostaglandin (MGA/PGF) and MGA/select synch estrous synchronization protocols in beef heifers. Journal of Animal Science. 2000. v. 78(Suppl. 2): Abstract p. 118.
• Geary, T.W. Heat detection systems and estrus management. Proceedings of Beef Improvement Federation. 1999. p. 24-31.
• Geary, T.W., Whittier, J.C., Lefever, D.G., Niswender, G.D., Nett, T.M., Hallford, D.M. Evaluation of the GnRH/PGF*2alpha protocols for synchronization of oestrus/ovulation in beef cows. Journal of Reproduction and Fertility. 1999. Abstract. v. Suppl. 54. p. 515.
• Sasongko, B.W.P., Whittier, J.C., Geary, T.W. Reduced dose Gnrh in select synch and co-synch protocols to synchronize estrus or ovulation in beef Cows. Journal of Animal Science Supplement. 2000. v. 78(Suppl. 1): Abstract p. 219.
• Sasongko, B.W.P., Whittier, J.C., Burns, P.D., Geary, T.W., Mortimer, R.G. Evaluation of fixed-time AI with GnRH on pregnancy rate of beef heifers synchronized with the MGA/PGF2alpha protocol. Journal of Animal Science. 2000. v. 78(Suppl. 2): Abstract p. 119.

Progress 01/01/99 to 12/31/99

Outputs
Feeding whole, rolled sunflower seeds as supplemental fat to first calf heifers for 65 d prepartum increased calf birth weight 2 kg and dystocia incidence 9% (NS). Feeding similar diets to mature cows for 77 d prepartum had no effect on birth weight or dystocia. Pregnancy rates and calf weaning weights in fat-supplemented heifers or cows that calved in February and placed on limited range forage were increased 6% and 13 kg and 6% and 1 kg, respectively. Data to date indicate forage availability during the postpartum-to end- breeding season can alter pregnancy response to gestation fat feeding but weaning weight tends to still be increased. Feeding fat to replacement heifers for 162 days prebreeding increased the percent heifers puberal at the beginning of the breeding season but pregnancy rates were not affected. Response was breed dependent with percent puberal in Piedmontese heifers being increased 22%. Cold tolerance of calves experiencing severe dystocia is markedly reduced compared to eutocial calves or calves delivered by C-section indicating need to provide these calves assistance in maintaining body temperature if survival is to be assured. Synchronization of estrus with GnRH and PG increased pregnancy rate 6% and a 6-d earlier conception date. Intensifying estrus detection techniques resulted in more timely AI and increased conception by 13%. Pregnant cows abort but elk do not when fed Ponderosa pine needles. This species difference results from elk being able to resist or deactivate the abortifacient compound in needles. Studies on the metabolism of the compound are underway.

Impacts
The predicted impact of these research efforts is a $50 million increase in annual production efficiency from the national beef herd.

Publications

• DEHORITY, B.A., GRINGS, E.E. and SHORT, R.E. 1999. Effects of cross-inoculation from elk and feeding pine needles on the .... J. Eukaryotic Microbiology. Accepted July 1999.
• FORD, S.P., ROSAZZA, J.P.N., AL-MAHMOUD, M.S., LIN, S. FARLEY, D.B. and SHORT, R.E. 1999. Abortifacient effects of a unique class of vasoactive ... J. Anim. Sci. 77:2187-2193.
• FUNSTON, R. and GEARY, T. 1999. Rebreeding the first calf heifer. Cow-Calf Management Guide and Cattle Producers Library 415:1-5.
• GEARY, T.W. and WHITTIER, J.C. 1999. Various protocols for synchronization of estrus or ovulation using GnRH and prostaglandin. 1999 Beef Program Report, CSU, p. 93-99.
• GRINGS, E.E., STAIGMILLER, R.B., SHORT, R.E., BELLOWS, R.A. and MACNEIL, M.D. 1999. Effects of stair-step nutrition and trace mineral supplementation... J. Anim. Sci. 77:810-815.
• LAMMOGLIA, M.A. SHORT, R.E. ... 1999. Induced and synchronized estrus in cattle: dose titration of estradiol benzoate in peripubertal ... J. Anim. Sci. 76:1662-1670.
• LAMMOGLIA, M.A., BELLOWS, R.A., GRINGS, E.E., BERGMAN, J.W., SHORT, R.E. and MACNEIL, M.D. 1999. Effects of feeding beef females supplemental fat .... J. Anim. Sci. 77:824-834.
• LAMMOGLIA, M.A., BELLOWS, R.A., GRINGS, E.E., ... 1999. Effects of ... supplemental fat and muscle hypertrophy... J. Anim. Sci. 77:2227-2233.
• SALVERSON, R.R., WHITTIER, J.C., DOWNING, E.R. and GEARY, T.W. 1999. Synchronization of ovulation using HCG or GnRH with the ... Proc. West. Soc. Am. Soc. Anim. Sci. 50:35-38.
• SALVERSON, R.R., SEIDEL, G.E., JR. and GEARY, T.W. 1999. Use of hCG or GnRH with the Select Synch Protocol in beef cows. J. Anim. Sci. 77(Suppl. 1): Abstr. 237.
• SALVERSON, R.R., WHITTIER, J.C., DOWNING, E.R. and GEARY, T.W. 1999. Synchronization of ovulation using hCG and GnRH with the Co-Synch ... J. Anim. Sci. 77(Suppl. 1): Abstr. 95.
• SALVERSON, R.R., ... and GEARY, T.W. 1999. Synchronization of ovulation using hCG and GnRH with the CO-Synch protocol in suckled beef cows. 1999 Beef Prog. Report, CSU, p. 69-74.
• STANTON, T.L., WHITTIER, J.C., GEARY, T.W., ... 1999. Effect of trace mineral supplementation on cow-calf performance, reproduction and ... 1999 Beef Program Report, CSU, p. 1-14.
• STENQUIST, N.L. and GEARY, T. 1999. Synchronizing estrus in beef cattle. Cow-Calf Management Guide and Cattle Producers Library 405:1-5.
• STENQUIST, N.L. and GEARY, T. 1999. Artificial insemination of beef cattle. Cow-Calf Management Guide and Cattle Producers Library. 400:1-5.
• BELLOWS, R.A., ... 1999. Effects of feeding supplemental fat during gestation on reproduction in primiparous beef heifers. J. Anim. Sci. 77(Suppl. 1):Abstr. p. 236.
• BELLOWS, R.A., LAMMOGLIA, M.A., GEARY, T.W. and FUNSTON, R.N. 1999. Effects of dystocia on cold tolerance ... newborn beef calves. J. Anim. Sci. 77(Suppl. 1):Abstr. p. 107.
• BELLOWS, R.A., LAMMOGLIA, M.A., GEARY, T.W. and FUNSTON, R.N. 1999. Effects of dystocia on cold tolerance in newborn beef calves. Proc. West. Sec. Am.Soc. Anim. Sci. 50:115-118.
• BELLOWS, R.A. and LAMMOGLIA, M.A. 1999. Effects of dystocia severity on cold tolerance and serum concentrations ... in neonatal beef calves. Theriogenology 51. In Press.
• DOHERTY, D.R., ..., GEARY, T.W. and RALPHS, M.H. 1999. Locoweed bite count correlation with serum swainsonine levels in cattle. J. Anim. Sci. 77:97. (Abstr.)
• DOHERTY, D.R., VAAD, J., GREATHOUSE, G., KNIGHT, A.P., GEARY, T.W., and RALPHS, M.H. 1999. Locoweed bite count ... in cattle. Proc. West. Sec. Am. Soc. Anim. Sci. 50:24-26.
• DOHERTY, D.R., WHITTIER, J.C. and GEARY, T.W. 1999. MGA/PGF **2alpha vs GnRH/PGF**2alpha, a comparison of two estrous... 1999 Beef Program Report, Colorado State Univ. p. 75-78.

Progress 01/01/98 to 12/31/98

Outputs
Primaparous, crossbred beef heifers (n=149) calving in three calving seasons (February, April, or June) were assigned randomly to one of four gestation diets: Control or added safflower seeds, soybeans, or sunflower seeds. Diets were isocaloric-isonitrogenous and contained 2.0, 4.2, 3.3, or 4.5% fat, respectively. Diets were group fed in dry lot and were fed for about 65 d precalving. Heifer weights and body condition scores (1-10) were obtained throughout the study; estrous cycling activity was based on progesterone content of blood samples obtained at beginning of breeding; pregnancy was determined by ultrasound at 60-90 d following 35-37 d estrous- synchronized breeding seasons. Calf data included birth weight, calving ease, sex, and weaning weight. Effects of fat supplementation on dam weight or body condition throughout the study were non-significant as were effects on birth weight, calving ease and dam estrous cyclicity at beginning of breeding. Heifers from fat supplemented groups had greater pregnancy rates (P<.05) and calf weaning weights (P=.09): Control, 79%, 182.4 kg; safflower seeds, 94%, 193.6 kg; soybeans, 90%, 197.7 kg; sunflower seeds, 91%, 196.8 kg (mean values pooled over calving seasons). Elk do not abort when fed needles from Ponderosa pines and transferring rumen contents from cows to elk fed pine needles did not result in abortions. Chemical analyses found no difference in rumen or blood metabolites of isocuprussic acid between cows and elk suggesting elk have the ability to inactivate this abortion-causing compound somewhere in the reproductive system.

Impacts
(N/A)

Publications

• Short, R.E., Kronberg, S.L., Grings, E.E., Rosazza, J.P., and Ford, S.P. 1998. Pine needle abortion. IRM Producer Education Seminars, Feb. 5-7, 1998, Denver, CO. P. 13-22.
• Lammoglia, M.A. ... 1998. Induced and synchronized estrus in cattle: Dose titration of estradiol benzoate in peripubertal heifers ...... J. Anim. Sci. 76:1662-1670.
• Rasby, R.J. ... 1998. Luteal function and estrus in peripubertal beef heifers treated with an intravaginal progesterone releasing device with or without a subsequent injection of estradiol. Theriogenology 50:55-63.
• Lin, S-J., Short, R.E., ... 1998. In vitro biotransformations of isocupressic acid by cow rumen preparations: formation of agathic and dihydroagathic acids. J. Natural Products 61(1):51-56.
• Ford, S.P. ... 1998. Use of late pregnant guinea pig to confirm the abortifacient effects of a unique class of vasoactive lipids in Pinus Ponderosa needles. J. Anim. Sci. (Accepted Nov. 98).
• Lammoglia, M.A., Bellows, R.A. ... 1998. Effects of feeding beef females supplemental fat during gestation on cold tolerance in newborn calves. J. Anim. Sci. (Accepted 9/28/98).
• Grings, E.E., Hall, J.B., Bellows, R.A. ... 1998. Effect of nutritional management, trace mineral supplementation, and norgestomet implant on attainment of puberty in beef heifers. J. Anim. Sci. 76(8):2177-2181.
• Kronberg, S.L., Walker, J.W., and Short, R.E. 1998. Predicting Ponderosa pine needle intake with NIRS and fecal samples. Proc. West. Sec. Am. Soc. Anim. Sci. 49:84-85.
• Lammoglia, M.A. ... 1998. Dose titration of estradiol benzoate(EB) in heifers & cows after treatment with an intravaginal progesterone releasing insert... Proc. West. Sec. Am. Soc. Anim. Sci. 49:180-184a.
• Fike, K., Day, M., Inskeep, K., Kinder, J., Lewis, P., Short, R., and Hafs, H. 1998. Induction of estrus in anestrous suckled beef cows. 1998 Nebraska Beef Report. Pp. 26-28.
• Bellows, R.A. (Bylined by Clint Peck). 1998. Feeding for calving time. Montana Farmer-Stockman. Mid-February. p. WB10, WB18.
• Bellows, R.A. (Bylined by Clint Peck). 1998. Thermogenesis 101 - Nothing beats a little heat. Montana Farmer-Stockman. February. p. WB1-WB2,WB6.
• Lammoglia, M.A., Bellows, R.A., Grings, E.E., and Bergman, J.W. 1998. Effects of prepartum supplementary fat and muscle hypertrophy genotype on cold tolerance in the newborn calf. J. Anim. Sci. (Accepted 12/4/98).
• Bellows, R.A., Lammoglia, M.A., Short, R.E. ... 1998. Effects of muscular hypertrophy sires on fetal gestation and birth traits. J. Anim. Sci. 76(Suppl. 1):279.
• Lammoglia, M.A. ... 1998. Dose titration of estradiol benzoate (EB) in heifers and cows after treatment with an intravaginal progesterone releasing(IVP4) insert & PGF2. J. Anim. Sci. 76 (Suppl. 1):244.
• Duckett, S.K. ... 1998. Effects of sire breed, sex, crude protein source, & time on finishing diet (TOF) on longissimus muscle fatty acid and cholesterol content of beef steers. J. Anim. Sci. 76 (Suppl. 1):254.
• Kronberg, S.L., Walker, J.W., and Short, R.E. 1998. Predicting Ponderosa pine needle intake with near infrared reflectance spectroscopy and fecal samples. J. Anim. Sci. 76 (Suppl. 1):98.

Progress 01/01/97 to 12/31/97

Outputs
Effects of feeding safflower seeds(37% oil) on puberty, birth weight, dystocia, calf cold tolerance & dam reproductive performance was studied. F1 Hereford, Limousin, or Piedmontese(H, L or P) heifers received diets with 1.9 or 4.4% fat from -/x 254 d. Puberty was affected(P<.05) by diet x sire breed with high fat-P youngest(356 d), H oldest(400d) & H intermediate(382 d). Fat increased heifers puberal by beginning of breeding season 9%(P=.06). Pregnant heifers were fed diets with 1.9% or 5.5% fat during the last 54 d of gestation. Fat had no effect on birth weight or dystocia. Calves from both diet groups were held at 0oC for 140 m. Rectal temps & plasma glucose were affected by diet x time(P<.01) & time(P<.01). Calves from high-fat dams were more cold tolerant & had higher glucose. P F1 calves had higher rectal temps & greater cortisol & glucose concentrations than H F1 calves Pine needles (PN) were fed and premature & term calves were held at 9oC for 200 min. Premature calves had lower rectal temps & plasma glucose(both P<.01). Dystocia decreased calf cold tolerance. Feeding fat increased pregnancy rates 19%(P=.06) & 10%(P=.22) in years 1 & 2. Feeding long hay resulted in greater (P<.05) body temp increase than did corn silage. NIR of fecal samples from cows fed PN showed NIR analyses could determine PN intake. Ruminal microbes from cattle metabolize isocupressic acid to agathic & dihydroagathic acid. Transferring ruminal microbes from elk to cattle does not prevent PN induced abortions.

Impacts
(N/A)

Publications

• HALL, J.B., STAIGMILLER, R.B., SHORT, R.E., BELLOWS, R.A., MACNEIL, M.D., & BELLOWS, S.E. 1997. Effect of age and pattern of gain on induction of puberty with a progestin in beef heifers. J. Anim. Sci.
• LAMMOGLIA, M.A. 1997. Body temperature and endocrine interactions before and after calving in beef cows. J. Anim. Sci. 75(9):2526-2534.
• FORD, S. P., ROSAZZA, J. P. N., & SHORT, R. E. 1997. Pinus Ponderosa needle-induced toxicity. In:( J. P. Felix D'Mello, Ed) Handbook of Plant & Fungal Toxicants. pp 219-29. CRC Press, Boca Raton, FL. (Book
• FIKE, K.E. 1997. Estrus & luteal function ... when treated with an intravaginal device containing progesterone with or without a subsequent injection of estradiol benzoate. J. Anim. Sci.
• JOHNSON, S.K. 1997. Onset of estrus and luteal function in peri- pubertal heifers given an intravaginal progesterone releasing insert ... estradiol benzoate. J. Anim. Sci. 75(Suppl. 1):231.
• BELLOWS, R.A. 1997. Maternal influences on dystocia. Proc., Canadian Veterinary Medical Association 49th Annual Conv., Saskatoon, Sask.,
• LAMMOGLIA, M.A. 1997. Effects of dietary fat composition and content, breed and calf sex on birth weight, dystocia, ... of first calf beef heifers. Proc. West. Sec. Am. Soc. Anim. Sci. 48:81-84.
• Short, R. E. 1997. Effects of elk and cattle rumen contents and dietary fat on abortifacient activity of pine needles. Proc. Wes. Sec. Am. Soc. Anim. Sci. 48:95-97.

Progress 01/01/96 to 12/30/96

Outputs
Supplementing pregnant heifers with safflower seeds during the last 60 d of gestation resulted in reduced birth weights of male calves, but not females, lower dystocia scores and improved pregnancy rates(all P<.05). Feeding safflower seeds to prepuberal heifers increased P4 concentrations, number cycling at the beginning of the breeding season(P<.05), but had no effect on puberty or pregnancy rates. Body temperature of dams gestating male calves was higher prepartum than dams gestating females(P<.01); cow body temperature dropped 8-24 hrs prepartum regardless of calf sex(P<.01). Hormonal effects on these endpoints were inconclusive. Sire breed had highly significant effects on fetal weight at both 183 and 242 d gestation with Belgian blue-sired calves the heaviest at both gestation ages. Vaginal pessaries with P4 inserted into heifers for 7d increased puberty incidence from 12% in controls to 32% and when E2 was given, to 66%(P<.01). Elk do not abort nor do they have vasoconstrictive activity (abortifacient compound) in the plasma after being fed needles from Ponderosa pine trees. Transferring rumen fluid from elk to cows before feeding needles was only marginally successful in preventing abortion. However, when elk rumen fluid was incubated in vitro with pine needles, 100% of the vasoconstrictive activity was removed.

Impacts
(N/A)

Publications

• BELLOWS, R.A., GENHO, P.C. MOORE, S. A., and CHASE, C.C. 1996. Factors affecting dystocia in Brahman-cross heifers in subtropical southeastern United States. J. Anim. Sci. 74:1451-1456.
• LAMMOGLIA, M.A. 1996. Effects of nutrition and cow temperature changes before calving on heat production in the newborn and survival rate. Proc. Mont. Governor's Conf. State of Cattle Industry, p. 66-69.
• BELLOWS, R.A. and HALL, J.B. 1996. Physiology and management of the replacement beef heifer. IN: L.M. Rode (ed.) Animal Science Research and Development: Meeting Future Challenges. p. 217-234.
• SHORT, R.E., FORD, S.P., ROSAZZA, J.P., FARLEY, D. B., KLAVONS, J.A. and HALL, J.B. 1996. Effects of feeding pine needles and pine needle components to late pregnant cattle. J. Anim. Sci. Abst. 74(Suppl. 1):256.
• BELLOWS, S.E., SHORT, R. E., and FORD, S.P. 1996. Effects of feeding pine needlesto late pregnant elk and goats. J. Anim. Sci. Abstr. 74(Suppl. 1):209.
• LAMMOGLIA, M.A., BELLOWS, R.A., STAIGMILLER, R. B., SHORT, R.E. .... 1996. Effects of sires with muscular hypertrophy on conceptus development at two stages of gestation. J. Anim. Sci. Abstr. 74(Suppl. 1):150.
• LAMMOGLIA, M.A., BELLOWS, R.A., STAIGMILLER, R.B., SHORT, R. E., BELLOWS, S.E. ..... 1996. Peripartum body temperature and hormonal interactions in beef cows. Proc. West. Sect. Amer. Soc. Anim. Sci. 47:209-212.

Progress 01/01/95 to 12/30/95

Outputs
Pregnant elk and goats did not abort when fed pine needles in amounts that caused abortion in cows. Supplemental protein with or without monensin prevented pine needle consumption in pregnant cows. Needles from Red pine (Pinus resinosa) did not cause abortions in cattle. Adding a synthesized, naturally occurring fatty acid with vasoconstrictive activity to methylene chloride extracted pine needle residue did not result in abortions in cows. Breed differences in puberty were, Piedmontese, Hereford and Limousin, youngest to oldest. Feeding heifers high caloric intake for 2 mo, low for 2 mo and high for 2 mo did not affect puberty compared to heifers fed a constant caloric intake. Zn supplementation during gestation affected dam weight, birth weight, and plasma Zn concentrations, but not dystocia; results were breed dependent showing a significant genotype x environment interaction. Calf birth weight had consistent effects (P<.01) on dystocia in heifers in Florida and the relationship between birth weight and dystocia score was curvilinear (P<.01). Body measurements at end of breeding season had no predictive value for birth weight or dystocia. Body temperature of pregnant heifers show a consistent drop prior to parturition.

Impacts
(N/A)

Publications

Progress 01/01/94 to 12/30/94

Outputs
Insulin concentration increased (P<.05) and IGF-I decreased (P<.05) during the puberal transition thus linking metabolic and puberal changes. Induction of puberty with progesterone is more dependent on age than body weight. Melatonin-induced changes in puberty are dependent on age and season. Additional FSH given at ovulation did not alter ovulation rate or number of recovered embryos, but reduce transferable embryos 50% (P=.10). Giving FSH as a single 400 or a split 300 plus 100 mg eq injection 48 hr apart did not affect ovulation rate. Body condition score did not affect ovulatory response. Abortifacient effects of feeding pine needles were not changed by regressing the pregnancy CL at d200 with PGF/2alpha or by transferring sheep rumen contents to pregnant cows. BrahmanX suppressed and JerseyX dams complemented (P<.05) fetal growth measured at d231 gestation. Serum testosterone concentrations were greatest in BrahmanX and LonghornX dams and lowest in JerseyX; differences were associated (P<.01) with placental membrane weight. Dams gestating male fetuses had greater testosterone concentrations than dams with female fetuses (P<.01).

Impacts
(N/A)

Publications

Progress 01/01/93 to 12/30/93

Outputs
Insulin concentration increased (P<.05) and IGF-I decreased (P<.05) during the puberal transition thus linking metabolic and puberal changes. Induction of puberty with progesterone is more dependent on age than body weight. Melatonin-induced changes in puberty are dependent on age and season. Additional FSH given at ovulation did not alter ovulation rate or number of recovered embryos, but reduce transferable embryos 50% (P=.10). Giving FSH as a single 400 or a split 300 plus 100 mg eq injection 48 hr apart did not affect ovulation rate. Body condition score did not affect ovulatory response. Abortifacient effects of feeding pine needles were not changed by regressing the pregnancy CL at d200 with PGF/2alpha or by transferring sheep rumen contents to pregnant cows. BrahmanX suppressed and JerseyX dams complemented (P<.05) fetal growth measured at d231 gestation. Serum testosterone concentrations were greatest in BrahmanX and LonghornX dams and lowest in JerseyX; differences were associated (P<.01) with placental membrane weight. Dams gestating male fetuses had greater testosterone concentrations than dams with female fetuses (P<.01).

Impacts
(N/A)

Publications

Progress 01/01/92 to 12/30/92

Outputs
Feeding pine needles did not offset rumen microflora populations. Gradually increasing amount of pine needles fed delayed but did not prevent abortion. Exposing lactating cows to bulls for 30 d post calving shortened the postpartum interval to first estrus. Transferred embryo pregnancy rates were greater in heifers at 3rd vs lst (puberal) estrus (P<.01). Of heifers not pregnant, Herefords exceeded Charalais (P<.05) in ultrasound evidence of some early embryonic development. Use of FSH with low contamination LH gave similar ovulation rates when given as a single or 4 d- 8 inj sequence, but the latter regime gave more transferable embryos. Age and body composition at puberty were influenced by diet and breed, but puberty did not occur at a specific body composition. Serum concentrations of testosterone in the pregnant dam were influenced by dam breed (P<.05), growth potential of the sire (P=-.08) and fetus sex (P<.01). Measure of dam size (live and carcass weight and pelvic area) had significant direct effects on fetus size. Fetal membrane weight had the largest effect of fetus weight.

Impacts
(N/A)

Publications

Progress 01/01/91 to 12/30/91

Outputs
One S.Q. FSH inj. gave superovulation similar to 4 daily I.M. inj.; 2 of 10 heifers responded to a single I.M. inj. Sperm transport in E2-treated prepuberal ewes was lower (P<.05) than at puberty, third estrus, or in mature ewes. E2-treated ewes were an unacceptable model for sperm transport. ET conception was 21% higher in heifers at third vs first estrus. Based on rg and CR values, a 10-cm**2 increase in pelvic area is accompanied by a .02 lower CD score and a .9 kg higher calf birth weight. Treatment of cows with insulin did not affect FSH superovulation in either CL or follicle numbers; correlations with blood glucose were nonsignificant. Cows on low feed had greater (P<.05) superovulation than those on high feed. Pelvic, body size and dystocia relationships are being studied in 400 heifers in Florida. Feeding 2.25-kg pine needles daily to late pregnant buffalo induced abortion (23 vs 8 d interval, in control and fed groups). Feeding adequate or high protein diets with or without salt had no effects on interval to abortion in cows fed pine needles ad lib. Cows fed pine needles free choice and isocaloric basal diets of hay or silage were compared; those on hay consumed more pine needles and had shorter intervals to calving (14 d) than those consuming silage (29 d). Silage-fed cows consumed few pine needles and no abortion occurred. Two research herds were dispersed due to a suspected disease problem; all tests were negative.

Impacts
(N/A)

Publications

Progress 01/01/90 to 12/30/90

Outputs
Injections of pig relaxin in heifers on d 4 or d 7 prepartum had no effect on gestation length, dystocia, retained placenta, cervical or pelvic changes or serum P4, E2 or PGF. Relaxin prolonged (P=.08) gestation and increased dystocia scores (P=.08). Dams with male fetuses had greater (P<.05) prepartum pelvic areas than those with female fetuses. Brahman (Br) & Hereford (H) F1 heifers were superovulated with a recombinant FSH. Br had higher (P<.01) ovulation rates and more (P<.05). Modeling of the postpartum interval revealed basic determinants in common explained correlations among trait responses studied. Exposing cows to bulls after calving hastened (P<.05) resumption of estrous cycles. Slaughter house ovary-oocytes were in vitro fertilized and developed to morula and blastocyst stage. Histology of sheep oviduct and uterus undergo changes during puberal transition in sheep; more than 2 h were required for sperm to reach the upper oviduct in peripuberal ewe lambs & sperm transport improved with successive estrous cycles. Fetus growth in utero is influenced by genetic and non-genetic factors associated with carcass skeletal-fat-muscle traits of the dam. Feeding pine needles results in a marked reduction in uterine blood flow that is associated with an abortificient-catechol estrogen interaction. Specific gravity was calculated from plethysmometer (volume) and body weight. Repeatability of weight was .998 and volume .968.

Impacts
(N/A)

Publications

Progress 01/01/89 to 12/30/89

Outputs
In vitro fertilized embryos were developed in co-culture with oviduct epithelialcells to the morula stage and by intermediate transfer to sheep oviducts to the blastocyst stage. Embryos from mature cows are transferred into heifers at puberty to evaluate the uterine environment of puberal heifers. Nutrition, ovary and follicle characteristics contributed to a multivariate model for developmental potential of individual oocytes. Cows were superovulated and bred to either a Jersey or Charolais sire. Conceptus data was collected at slaughter at 95, 180 or 250 d gestation. Sire differences were nonsignificant at 95 d, but sex and single vs multiple were. Fetal brain and heart tissue were apparently most competitive for available nutrients. Multiple fetuses were under a nutritional stress that became more pronounced as gestation progressed. Fetal growth potential had a positive effect on type pregnancy and growth potential. Differences in metabolites between maternal and fetal circulation were found in blood obtained at 223 d gestation. Injection of heifers with porcine relaxin at d 7 or 4 prepartum had no effect on prepartum dam changes or parturient physiology. Successful pregnancies were obtained with bovine embryos transported from BARC to LARRS in a rabbit. Biotech FSH is an active superovulating agent, but ovarian response is variable. Results give important insights to scientist on embryo physiology and fetal growth.

Impacts
(N/A)

Publications

Progress 01/01/88 to 12/30/88

Outputs
In vitro fertilized embryos were developed in co-culture with oviduct epithelialcells to the morula stage and by intermediate transfer to sheep oviducts to the blastocyst stage. Embryos from mature cows are transferred into heifers at puberty to evaluate the uterine environment of puberal heifers. Nutrition, ovary and follicle characteristics contributed to a multivariate model for developmental potential of individual oocytes. Cows were superovulated and bred to either a Jersey or Charolais sire. Conceptus data was collected at slaughter at 95, 180 or 250 d gestation. Sire differences were nonsignificant at 95 d, but sex and single vs multiple were. Fetal brain and heart tissue were apparently most competitive for available nutrients. Multiple fetuses were under a nutritional stress that became more pronounced as gestation progressed. Fetal growth potential had a positive effect on type pregnancy and growth potential. Differences in metabolites between maternal and fetal circulation were found in blood obtained at 223 d gestation. Injection of heifers with porcine relaxin at d 7 or 4 prepartum had no effect on prepartum dam changes or parturient physiology. Successful pregnancies were obtained with bovine embryos transported from BARC to LARRS in a rabbit. Biotech FSH is an active superovulating agent, but ovarian response is variable. Results give important insights to scientist on embryo physiology and fetal growth.

Impacts
(N/A)

Publications

Progress 01/01/87 to 12/30/87

Outputs
Fetal-maternal GEI effects on 231-d fetuses were determined in 5 breeds of F1 dams bred to high or moderate growth-potential sires. Fetal genotype X maternal environment effects were found for fetus weights, skeletal size, fetus organ weights and placental membrane weights. Pregnancy rate of dams that lost calves was 7.0% lower than for dams not losing calves. Of 1160 calves necropsied, 78% calves were anatomically normal, 22% abnormal, 1.1% had perforated abomasal ulcers and 0.3% had a missing segment of the caudal gut. Induced parturition and early obstetrical assistance can be combined. Cows injected with equine gonadotropin had fewer ovulations but a higher percent of good quality embryos as compared to cows injected with porcine FSH. P4 was higher during the puberal estrous cycle as compared to the third cycle. Ovulation rate was lower in superovulated cows fed a high energy vs. a low energy ration. Quantity of cumulus cells attached to an oocyte was correlated with oocyte maturation (r=.44) and development (r=.21) in vitro. Stress delays abortion after pine needle feeding, and this effect is reduced by a 3-wk adjustment period. Pelleting pine needles partially destroys or removes their abortifacient effects. Feeding 4 mg of MGA delayed abortions caused by feeding pine needles. Findings are useful to scientists and producers for understanding reproductive processes and to decrease losses.

Impacts
(N/A)

Publications

Progress 10/01/85 to 12/30/86

Outputs
Heifers had a higher pregnancy rate when bred at 1st vs 3rd estrus (78% vs 57%, P<.01). When estrus was classified as nonpuberal, conception rate was 0%. Thin body condition increased follicular development in cows treated with exogenous gonadotropins. Fetal-maternal GEI was evident when a high birth weight sire increased dystocia 0% in Longhorn and Brahman, 18% in Shorthorn, 41% in Charolais, and 44% in Jersey dams. Correlations between pelvic area and dystocia score ranged from 0 in Jersey dams to -.84** in Shorthorn dams. Correlations between birth weight and CD score ranged from -.48 in Longhorn dams to .77* in Shorthorn dams. High carcass fatness decreased cotyledon weight and fetal growth. Survival of calves born in backward presentation exceeded (P<.01) that of breech calves (71 vs 33%). Of calves dying at birth, 40% had functional and 60% had nonfunctional lungs (P<.01). Incidence of abortions in cows fed pine needles increased with stage of pregnancy (4 mo, 0%; 5 1/2 mo, 37%; 7 mo, 50%; 8 1/2 mo, 100%; P<.01). Increasing the amount of pine needles fed starting at 250 d increased abortion rate and decreased the interval to parturition (1.5 lb, 80%, 19.0 d; 3.0 lb, 90%, 16,8 d; 6.0 lb, 100%, 10.1 d; P<.01). Postpartum cows given an opiod antagonist had an initial increase and then a decrease in LH secretion.

Impacts
(N/A)

Publications

Progress 07/01/85 to 09/30/85

Outputs
This is a new project with a short period of time since being started. Experiments are continuing in the areas of puberty, dystocia, postpartum anestrus, pine needle abortion, folliculogenesis, oocyte maturation and embryo transfer. A continued drought has forced a major reduction in cattle numbers which has reduced animal numbers available for dystocia, postpartum and basic studies. One herd of 68-1st calf heifers was moved to Dubois, ID for grazing in order to salvage data collection before selling. Cows and heifers have been bred to continue studies on the maternal control of fetal growth and dystocia. This study involves a wide range of genotypes from Jersey to Brahman. An extract from horse pituitaries is being developed and tested to be used for follicle, superovulation and embryo studies. Embryo collection and transfer techniques are being perfected. A pine needle abortion study showed that state of pregnancy has a marked effect on incidence of abortions when cows are fed pine needles. Percent aborting by stage of pregnancy was 3 1/2 mo.-12.5%; 5 mo.-25%,6 1/2 mo.-50% and 8 mo.-100%. Correlated hormone data is being developed from assays. See Progress Report MONB00918 for earlier accomplishments to 06/30/85.

Impacts
(N/A)

Publications