Polymorphic variants of the CD62L and ACSL1 genes in connection with the resistance of cows to mastitis

Relevance. In conditions of intensive dairy cattle breeding, the incidence of cows with mastitis continues to be an urgent problem. The number of somatic cells (CCCs) in milk is a breeding indicator for improving the health of the mammary gland of cows. The study of animal resistance to the disease, which is based, among other things, on the genetic component, will make it possible to increase the efficiency of breeding in the future. The purpose of this work is a comparative analysis of the relationship of polymorphic variants of the ACS L1 (rs208522533) and CD62L (rs41803917 and rs41803917) genes with indicators of milk productivity and the level of somatic cells in the milk of Ayrshire cows. Methods. A sample of first-calf cows of Ayrshire breed ( n = 191) belonging to one of the breeding farms of the Leningrad region was formed. Animal genotypes were determined by PCR-PDRF. Analysis of the genotype frequency by rs208522533 of the ACS LI gene showed that 99% of the animals were carriers of the GG genotype. Results. The results of studies of the CD62L gene showed that rs41803917 determined a high frequency of the G allele (80.4%) and on average more than 60% of animals had the GG genotype. rs109966956 of the CD62L gene revealed a high frequency of the C allele (80.1%) and 64.9% of the animals had the CC genotype. High values of BOX PC were established in small groups of animals with the AA genotype according to rs41803917 ( p £ 0.05) and the TT genotype according to rs109966956 ( p £ 0.001). Individuals with the AG genotype according to rs41803917 of the CD62L gene had high protein percentages ( p £ 0.05) and low BSC ( p £ 0.05). The results obtained indicate that SNPs rs41803917 and rs41803917 of the CD62L gene can be considered as potential markers of resistance to mastitis in Ayrshire cows.