Comparative genetic characteristics of the microsatellite profile of Jersey and Holstein cows bred in the Republic of Tatarstan

The most accurate and fastest tool in solving issues of genetic identification of animals, regardless of their physiological condition and age, are microsatellites (STR - Short Tandem Repeats), which are markers and have a number of features. Information on the genetic diversity of the cattle population by microsatellite markers can be used not only to study the genetic structure, but also to confirm the origin of offspring by parents. In the studied group of Jersey and Holstein cattle, the average number of microsatellite alleles per locus was 7.5-7.6. The average number of effective alleles of the studied loci in the Jersey breed was 3.2 and in the Holstein breed 3.7. The highest levels of observed and expected heterozygosity in the Jersey breed (0.767 and 0.882) were found at the Eth10 locus, and the lowest (0.581 and 0.559) at the Bm1824 locus. The average level of observed and expected heterozygosity was approximately 0.672 and 0.702. In the Holstein breed, the highest values of observed and expected heterozygosity were found at the Tgla122 locus (0.839 and 0.893), and the lowest 0.466 and 0.472 at the Sps115 locus. The average level of observed and expected heterozygosity was 0.694 and 0.693. The Wright fixation index was -0.047 for the Jersey breed and 0.049 for the Holstein breed. It should also be noted that the results of microsatellite DNA analysis must be taken into account and applied to develop plans for selection and breeding work, assess the genetic structure of breeds, and maintain the level of heterozygosity in herds.