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ARS Home » Plains Area » Miles City, Montana » Livestock and Range Research Laboratory » Research » Research Project #423791

Research Project: Alleviating Rate Limiting Factors that Compromise Beef Production Efficiency

Location: Livestock and Range Research Laboratory

2016 Annual Report


Objectives
1: Determine the impact of the level of harvested feed input on the sustainability of beef production systems, including annual reproductive success, lifetime productivity, and progeny performance. 2: Evaluate use of dormant, animal-harvested forages as a substitute for mechanically harvested feeds in developing replacement heifers. 3: Develop new and better genetic and physiological indicators of fertility in yearling bulls and beef cows to enhance annual and life-cycle reproductive success. 4: Assess locus-specific genetic effects attributable to heterozygosity on reproductive success and productivity in production systems making differential use of native range forages. 5. Improve breeding and management decisions by characterizing current genetic and phenotypic variation within and between predominant beef breeds and crosses using novel genomic and genetic evaluation technologies and identify novel genomic variants to optimize forage based production efficiencies for beef cattle within and across diverse physical environments in the US Great Plains.


Approach
Feed consumption and replacement of cows, culled for reproductive failure, are two primary determinants of beef production efficiency. Our overarching goal is to develop strategies and technologies to alleviate these limitations. Sufficient nutrient intake resulting in adequate body energy stores are believed essential for reproduction. Thus, producers are challenged to match nutritional environment, which is subject to seasonal and annual variation, and various genotypes to obtain sustainable reproduction and retention rates. Our approach is, of necessity, long-term and multi-disciplinary, involving both basic and applied aspects of genetics, nutrition, and physiology in a semi-arid grazing production system. This proposal brings to fruition ongoing research and establishes investigations of genetic by environmental interactions and physiological mechanisms limiting reproductive success. Four distinct cattle populations (an intercross of Charolais (25%), Red Angus (50%) and Tarentaise (25%), Line 1 Hereford, purebred Angus, and Hereford-Angus herd) will be used to facilitate assessment of genetic factors affecting fitness (hybrid vigor). Distinct nutritional environments that utilize different contributions of harvested and grazed forage will be imposed to challenge the nutrition-reproduction interface to elucidate genetic, physiological, and management factors influencing feed utilization and lifetime productivity. Identification of genetic, nutritional, and physiological mechanisms that limit or contribute to beef production efficiency will facilitate early in life selection and management of replacement animals most fit for particular production environments. This research will result in the establishment of heifer development protocols that provide producers options for dealing with annual variations in availability and quality of forage.


Progress Report
1. Phenotypic and genotypic data continue to be collected to complete objective 1,to assess the impact of the level of harvested feed input on the sustainability of beef production systems, including annual reproductive success, lifetime productivity, and progeny performance. Data have been analyzed to determine the effects that level of harvested feed provided to the individual animal and its dam have on herd retention. These accomplishments build the mass of critical data needed to evaluate economic and biological impacts harvested feed inputs may or may not elicit in promoting high lifetime productivity. 2. Heifer calves born in 2015 as contributed to Objective 2, were subjected to experimental treatments (fenceline weaned and pasture developed vs. feedlot weaning and development). Methodology was established to measure supplemental feed intake, heart rate and activity in individual animals in pasture setting. Assessment of resting heart rate and activity were successfully determined in 63 range heifers at 6 periods during the year. Behavioral responses to development treatments were assessed and preliminary analysis has been completed. 3. Animal sample collection is complete for Objective 3, with tissue, serum and DNA analysis for determination of new and better genetic and physiological indicators of fertility. GWAS analysis has revealed 29 SNPs, including 9 SNPs on the X-chromosome that were highly significant (P < 0.00000005) between heifers characterized as highly fertile verses subfertile. RNA-Seq analysis revealed 7 genes that were differentially expressed by the d 15 endometrium between these two fertility subclasses. Significant progress using flow cytometry and fluorescence imaging has revealed 5 novel measures of bull fertility and contributed to understanding various environmental influences on bull fertility. Sufficient offspring have not been produced to evaluate bull or cow fertility in the heterosis study. 4. Purchased and reared Angus females have been added to the herd to accomplish Objectives 4 and 5. Data on feed intake, postweaning development traits and fertility were collected along with DNA and SNP data. Third year of F1 progeny are on the ground leading to deeper data collection of both phenotypic and genotypic data. Initiated development of advanced statistical models.


Accomplishments


Review Publications
Funston, R.N., Grings, E.E., Roberts, A.J., Tibbets, B.T. 2016. Choosing a calving date. Professional Animal Scientist. 32:145-153.
Mulliniks, J.T., Sawyer, J.E., Harrelson, F.W., Mathis, C.P., Cox, S.H., Loest, C.A., Petersen, M.K. 2015. Effect of late gestation bodyweight change and condition score on progeny feedlot performance. Animal Production Science. doi. 10.1071/ANI5025.
Pohler, K.G., Green, J.A., Geary, T.W., Peres, R.G., Pereira, M.C., Vasconcelos, J.M., Smith, M.F. 2015. Predicting embryo presence and viability. IN: Regulation of Implantation and Establishment of Pregnancy in Mammals. Editors: R. D. Geisert and F. W. Bazer. Chapter 13:243-270.
Geary, T.W., Burns, G.W., Moraes, J., Moss, J.I., Denicol, A.C., Dobbs, K.B., Ortega, M.S., Hansen, P.J., Wehrman, M.E., Neibergs, H., O'Neil, E., Behura, S., Spencer, T.E. 2016. Identification of beef heifers with superior uterine capacity for pregnancy. Biology of Reproduction. 95(2):47, 1-12.
Geary, T.W., Kelly, W.L., Spickard, D.S., Larson, C.K., Grings, E.E., Ansotegui, R.P. 2016. Effect of supplemental trace mineral level and form on peripubertal bulls. Animal Reproduction Science. 168:1-9.
Waterman, R.C., Geary, T.W., Petersen, M.K., MacNeil, M.M. 2016. Effects of reduced in utero and post-weaning nutrition on milk yield and composition in primiparous beef cows. Animal-The International Journal of Animal Biosciences. 11(1): 84-90. doi:10.1017/S1751731116001257.
Roberts, A.J., Funston, R.N., Grings, E.E., Petersen, M.K. 2016. Beef heifer development and lifetime productivity in rangeland-based production systems. Journal of Animal Science. 94:2705-2715.
Petersen, M.K., Muscha, J.M., Mulliniks, J.T., Roberts, A.J. 2016. Water temperature impacts water consumption by range cattle in winter. Journal of Animal Science. doi:10.2527/jas.2015-0155.