Abstract
The article presents the results of genotyping of Holstein cows of Bayserke-Agro LLP, Talgar district, Almaty region, for the estrogen receptor gene locus, ERα/BGLI SNP polymorphism. In the studied animals, the distribution of genetic variants by the ERα gene locus was established; The results of DNA testing indicate that the DNA of the tested cows has a violation of gene balance, in cows the G allele is predominantly found, the frequency of which was 0.83. The reproductive function of 120 cows with different genetic variants of the ERα gene was monitored and it was found that animals with good indicators of reproductive function had a heterozygous AG genotype. Also, to determine the associative effect of ERα gene alleles on the reproductive ability of cows, the index of non-return of cows on the 58th day after artificial insemination was determined, and according to this criterion, cows with a heterozygous AG genotype had advantages compared to animals with homozygous AA and GG genotypes. Conducting genotyping of cows at the ERα gene locus by PCR-RFLP analysis allows determining the genotype of animals and ERα/BGLI SNP polymorphism is recommended as a DNA marker of reproductive function in cows.