Biochemical status and productive qualities of cows of Holstein breed of foreign selection of different genotypes of PON1 gene

DNA testing of antioxidant status genes polymorphism and the use of PON1 gene as a QTL biomarker is a promising direction in animal breeding, along with traditional selection methods. The aim of the study was to investigate the biochemical profile and productive qualities of cows of Holstein breed of foreign selection of different genotypes of PON1 gene. In the course of the study 231 Holstein cows of the Mukhametshin Z.Z. Peasant Farm Enterprise (PFE) of the Sabinsky district of the Republic of Tatarstan were genotyped for PON1-Bsc4I loci (SNP -211.Arg?Gln, A/G). In the course of DNA-diagnostics on the PON1 gene 2 alleles and 3 genotypes were detected. The frequency of occurrence for alleles A and G was 0.582 and 0.418. The distribution of genotypes in the population was as follows: AA - 33.3 %, AG - 49.8 and GG - 16.9 %. The genetic groups of animals obtained as a result of identification were evaluated for biochemical status, dairy productivity and milk quality, as well as for reproductive ability. Despite the higher number of milking days per lactation established in animals with AA genotype (353.5 days), the maximum milk yield per standard lactation (8322.7 kg) was observed in animals with GG genotype. They also had high milk yield coefficient (1675.3), mass fraction of fat in milk (3.84 %), milk fat and protein yield (317.1 and 254.7 kg) and their sum, as well as characterized by low somatic cell content (< 250 thds./cm?) and urea in milk, and the absence of acetone. The group of GG-type animals favorably differed from their counterparts with other genotypes in the following reproductive qualities: the shortest calving interval, open day and service period, high reproductive capacity coefficient (1.02) and index of Dohi (51.3), higher yield of live calves per 100 cows (99.2 animals). The obtained data make the cows with GG genotypes desirable for use in selection programs for breeding animals with improved traits of productivity and reproductive ability as the most resistant to oxidative stress.