Interaction of economically useful traits in cows of different breeds

A related Holstein breed has recently been used to improve domestic dairy cattle and create highly productive herds by purchasing semen from breeding bulls, as well as a large number of heifers and calves of foreign breeding. The purpose of the work is a comparative assessment of the productive qualities of Black Pied and Holstein cows of foreign breeding. Purebred Holstein cows differ from animals of Black Pied breed in milk yield per lactation. Cows of both breeds have fairly high suitability for machine milking. The priority remains with the animals of the Holstein breed of foreign selection. In terms of milking intensity and udder volume, they reliably surpass Black Pied cows at P≤0.05 - P≤0.01, respectively, in terms of indicators. Holstein cows were also the best in the udder index. Correlation coefficients between the productive qualities, as well as between the quantitative indicator of productivity and the qualitative indicators of the suitability of cows for machine milking, were the same or did not differ significantly. A positive correlation was established between milk yield and the duration of the service period from 0.1 to 0.05, depending on the breed