Research on the influence of the genetic potential of cows on the level of their milk productivity was carried out on the basis of the Prigorodny Agricultural production cooperative - the Republic of Mari El of the Russian Federation. The object of research was Holstein cows of black-and-white breed in the number of 352 cows.The level of dairy productivity of cows in the Prigorodny Agricultural production cooperative is at a high level. The milk yield of cows in the average herd made up 5805 kg Mass fraction of fat of 4.01%. The mass fraction of protein is 3.03%. When studying the influence of the genetic potential of cows on the level of dairy productivity in the farm, it was found that with an increase in the genetic potential, the milk yield of cows increases. A small positive correlation was found between the parent index of cows and milk yields (for 1 lactation, maximum and average) (r=0.2).As a result of research, it was found that the realization of the genetic potential in animals of different lines varied: milk yield-from 85% to 110%, fat mass fraction - from 97 to 102%, protein-from 95 to 96%. It was found that animals of the PubstGoverner 882933 line realized their genetic potential.