Frequency distribution of polymorphic variants of the beta-casein locus in Russian various breed cattle subpopulations

Abstract

Using the author’s test system, 2607 Holstein, Ayrshire and Jersey breeds were genotyped at CSN2 locus. It was determined that the frequency of preferred genotype A2A2 is in Holstein, Ayrshire and Jersey groups of animals - 0.21; 0.25 and 0.60 respectively. The frequency of A2 allele in Holstein breed is 0.48; in Ayrshire - 0.51; in Jersey - 0.78. Thus, the Russian subpopulations of Ayrshire, Jersey, and Holstein cattle subpopulations according to frequencies of A2A2 genotypes (CSN2 locus), the Jersey breed has the best indicators (0.60). Russian breeding enterprises selling semen production of Ayrshire and Holstein bulls should increase the share of breeders with CSN2 genotypes A2A2.