Plant & Animal Genomes XVII Conference

January 10-14, 2009
Town & Country Convention Center
San Diego, CA

Identification Of QTL For Behavior, Feed Efficiency And Carcass Traits In Bos indicus Influenced Beef Cattle

Clare A. Gill , Tonya S. Amen , Rebecca R. Funkhouser , Kristin L. Nicholson , Clayton R. Boldt , Lauren L. Hulsman , Sarah M. Vitanza , Mary Anne Wegenhoft , Kris R. Wunderlich , Colette A. Abbey , Jungwoo Choi , C. Michael Dickens , Andy D. Herring , Penny K. Riggs , Jason E. Sawyer , Jeffrey W. Savell , Rhonda K. Miller , David K. Lunt , James O. Sanders

  Department of Animal Science, Texas A&M University, 2471 TAMU, College Station, TX, 77843-2471, USA

The objective of the McGregor Genomics Project is to identify QTL and major genes for traits affecting production efficiency. From 2002 to 2007, we produced Nellore-Angus F₂ cattle by multiple ovulation and embryo transfer. In addition, paternal half-sibs were produced by natural service and identified by parentage testing. Approximately ~41 million genotypes for the McGregor population (n = 780) were obtained using microsatellites and the Illumina BovineSNP50 assay. In animals from the F₀ generation, 78% of the SNP segregated in Angus and 49.6% segregated in Nellore, with 85.2% of the SNP segregating in Angus or Nellore and 42.5% segregating in both Angus and Nellore. Only 0.8% of SNP were fixed for alternate alleles in Angus and Nellore. On average, there were 29,692 informative markers per F₂ family or one informative marker every 101kb. Linkage and combined linkage and linkage disequilibrium approaches were used for QTL analysis. In initial analyses, there were 44 highly suggestive (P < 0.01) and 144 suggestive (P < 0.05) QTL identified on 24 autosomes for feed efficiency, 34 carcass and meat traits, and 4 component traits of behavior measured at weaning (aggressiveness, nervousness, flightiness, gregariousness). Several of the QTL identified in this study previously have been reported but many of the QTL are novel and warrant further investigation. This project was funded in part by America's beef and veal producers through the $1 per head checkoff and National Research Initiative Grant no. 2007-35604-17870 from the USDA Cooperative State Research, Education, and Extension Service.