|Thomas, Milton -|
Submitted to: Journal of Animal Science Supplement
Publication Type: Abstract Only
Publication Acceptance Date: April 15, 2013
Publication Date: July 8, 2013
Citation: McDaneld, T.G., Kuehn, L.A., Thomas, M.G., Snelling, W.M., Pollak, E.J., Smith, T.P.L., Keele, J.W. 2013. Genome-wide association study of reproductive efficiency in female cattle [Abstract]. Journal of Animal Science. 91 (E-Supplement 2):392. (Abstract #319). Technical Abstract: Reproductive efficiency is of economic importance in commercial beef cattle production, as failure to achieve pregnancy reduces the number of calves marketed per cow exposed to breeding. Identification of genetic markers with predictive merit for reproductive success would facilitate accurate prediction of daughter pregnancy rate in sires enabling effective selection of bulls producing daughters with improved fertility. To identify regions of the genome harboring variation affecting reproductive success, we applied a genome-wide association approach based on the >700,000 SNP marker assay. To include the largest number of individuals possible under the available budget, cows from several populations were classified according to reproductive efficiency, and DNA was pooled within population and phenotype prior to genotyping. Populations evaluated included a research population at USMARC, 2 large commercial ranch populations, and a number of smaller populations (<100 head) across the US. Significant associations for reproductive efficiency were detected by this approach on BTA 5, 13, 15, 18, and 29. A genomic segment located on BTA 5, spanning the region of 25-70 Mb, contained 223 SNP having significant association with classification, representing the most robust signal in the genome. The remaining significant SNP lie on BTA 13 (4 SNP), BTA 15 (1 SNP), BTA 18 (1 SNP), and BTA 29 (1 SNP). In addition to our novel findings, we confirmed previously published associations for over 200 SNP encompassing substantial diversity including Bos indicus and Bos taurus breeds. From these data we have identified regions of the genome associated with reproductive efficiency. These regions are being evaluated further to identify specific DNA variations that are impacting reproduction in beef cattle.