Effect of the bovine TG5 gene polymorphism on milk- and meat-producing ability

Aim This study aimed to determine the effect of thyroglobulin (TG5) gene polymorphism on milk and meat productivity in the various cattle breeds currently bred in the Republic of Bashkortostan. Materials and Methods The test was performed on dairy cattle of Black-and-White, Bestuzhev, and Simmental breeds, and meat cattle of Hereford and limousine breeds. The purpose of the test was to search for associations between the polymorphic alleles of the thyroglobulin (TG5) gene and economically useful traits. Results All studied breeds showed a frequency predominance of the TG5C allele (from 0.56 to 0.71). A clear trend of an effect of the genotypes of the TG5 gene on milk-productivity indicators was revealed; cows with the TG5TT genotype have the highest milk yield and fat content in milk. The milk of cows of Bestuzhev and Simmental breeds that possessed this genotype was also characterized by higher protein content. Conclusion We identified an effect of the polymorphism of the TG5 gene in the Hereford and limousine breeds on fat metabolism intensity indicators, such as fat output and fat content, in the longissimus muscle and in the general sample of ground beef.