Structure of subopopulations of Aireshire, Holstin and Jersey cattle in the Southern Regions of Russia by CSN2 (rs43703011), CSN3 (rs43703016) and microsatellite locuses (BM1818, BM1824, BM2113, ETH10, ETH225, ETH3, INRA023, SPS115, TGLA126, TGLA122,

During studies using molecular biological methods, the following loci were genotyped: BM1818, BM1824, BM2113, ETH10, ETH225, ETH3, INRA023, SPS115, TGLA126, TGLA122, TGLA227, TGLA53, CSN2 (rs43703011) and CSN3 (rs43703 016) 3000 cow blood samples Ayrshire, Holstein and Jersey breeds from the herds of the Krasnodar and Stavropol territories. On average, the frequency of occurrence of homozygous genotypes for 12 microsatellite loci in Jersey cattle was 0.38, in Holstein and Ayrshire cattle – 0.30 and 0.27, respectively; the highest allelic diversity was found in Holstein cattle (9.0 ± 1.7 alleles per locus). It should be noted that there are significant differences in the genetic profile of Ayrshire cattle. For Ayrshire animals, the following alleles turned out to be typical (but rare in Jersey and Holstein cattle): 270 locus BM1818, 137 locus BM2113, 213 locus ETH10, 119 locus ETH3, 142 locus ETH225, 87 locus TGLA227, 166 locus TGLA53. In the studied subpopulation of Jersey cattle, the frequency of occurrence of the A2A2 genotype of the CSN2 locus (rs43703011) (beta casein) was 0.68, and in the Ayrshire and Holstein groups it was only 0.25 and 0.31, respectively. The BB genotype of the CSN3 locus (rs43703016) (casein kappa) was found in the Jersey group of animals with a frequency of 0.76, and in Ayrshires and Holsteins – 0.04 and 0.15, respectively. The genotyped groups of Jersey, Ayrshire and Holstein animals are significant in volume; we assume that the identified patterns are typical for cattle of these breeds in the south of Russia. We believe that the data obtained can be used in the future in practical work on classifying certain groups of livestock as typical Holstein, Ayrshire or Jersey and when creating herds that produce milk of a certain type (for example, type A2 milk).