RESUMO
We examined the allelic and genotypic polymorphisms of genes of the retinoic acid receptor-related orphan receptor C (RORC), diacylglycerol acyltransferase-1 (DGAT1), and growth hormone (bGH) in Russian beef cattle breeds in two populations of Kazakh white-headed cattle (of Kazakh and Russian selection) and in the Kalmyk cattle breed and Mongolian hogorogo breed, which is related to Kalmyk breed. The studied genes are associated with parameters of meat quality: marbleness (bGH and RORC) and tenderness (DGAT1). They are also associated with an increase in carcass weight (bGH). We found that Russian and Kazakh populations of the Kazakh white-headed.breed were characterized by a high content of the AA genotype of RORC (0.713 and 0.608, respectively) and of the AA genotype of DGAT1 (0.913 and 0.975), both of which are preferable for meat quality. The total frequencies for the combined genotypes for the bGH and RORC genes, which provide for superior meat quality and carcass weight, in the populations of Kazakh white-headed cattle (GG/AA and GC/AA-68.8% and 57% in the Russian and Kazakh populations, respectively) exceeded the frequencies in the two other studied breeds by two times. Overall, the obtained results point to the high genetic potential of both populations of Kazakh white-headed cattle breeds in beef production. Results of this study can be used to improve the selection of meat traits in industrial livestock.
