Abstract
Abstract SNP polymorphism of the TNFα gene’s promoter region at position 824 A→G in Holstein cows of TOO Bayserke-Agro is represented by the following genetic variants: AA, 22.4%; AG, 63.8%; GG, 13.8%; the frequency of alleles A and G was 0.54 and 0.46, respectively. The population under study revealed an excessive frequency of the heterozygous genotype AG, 21.49 individuals, while other genotypes showed a deficit of homozygous variants GG and AA, by 11.16 and 10.32 individuals, respectively. The traits of reproductive function were high in cows with genotype GG: the interval between calving and productive insemination was 259 days, the insemination index was 2.63, the proportion of animals inseminated after more than 91 days was minimal (47.36%) in individuals with the homozygous genotype GG. As an additional criterion for estimating the fertility of bull sperm, the DNA fragmentation method is recommended: the maximum permissible level of sperm cells with DNA fragmentation in frozen sperm is between 13.00 and 17.15%.