Candidate genes for growth traits in beef cattle crosses Bos taurus x Bos indicus

Candidate gene strategy has been proposed to direct the search for quantitative trait loci, and polymorphisms at these loci have been associated with several production traits in bovine. A total of 211 animals resulting from crosses between Nelore females with sires from either Aberdeen Angus, Canchim and Simmental breeds were analyzed for restriction fragment length polymorphisms (RFLPs) in the kappa -casein, beta -lactoglobulin (LGB) and growth hormone GH genes. Average daily gain from birth to weaning (GBW) and from weaning to yearling (GWY) were analyzed by a statistical model comprising RFLP genotypes and their interaction effects. Significant effects (p < 0.05) of growth hormone (GH ) and of the interaction beta -lactoglobulin x GH were verified for the GWY. Animals with LL genotypes for GH had higher GBW than LV animals but lower GWY (p < 0.05).