The live weight and milk production index of black-and-white and Tatarstan type cows of the Kholmogory breed with different genotypes for genes CSN3, DGAT1, PRL, GH were studied. It was found that cows with the homozygous genotype CSN3 AA, DGAT1 AA, PRL AA, GH LL are characterized by a high milk yield index. Unlike other marker genes, the somatotropin gene had a greater effect on the body weight and milk production index of cows. Thus, in terms of live weight in the black-and-white breed, the superiority of individuals with the GH LL genotype by 43 kg (P <0.001), GH LV by 42 kg (P <0.001) was noted, and in terms of milk production, the advantage of cows with the GH LL genotype (984 and 1008) over GH LV by 40 (P <0.01); on the Kholmogory breed above GH LV by 26 (P <0.05), GH VV by 42 (P <0.05). Consequently, cows with allelic A variant of the CSN3, DGAT1, PRL genes and allelic L GH genes in their genomes exhibit high milk production at optimal live weight.