The interrelation of the Russian Black Pied breed productive qualities of the Ural type depending on live weight

Holsteinized Russian Black Pied cattle of the Ural type are bred in the Sverdlovsk region, which is represented by large, highly productive animals with a high genetic potential for productivity. The purpose of the work was to study the effect of first heifers’ live weight on their productivity and the interrelation between milk yield and milk quality indicators. It was found that there was a positive tendency for an increase in milk yield with an increase in the cows’ live weight from less than 550 kg to 624 kg. The most significant increase in milk yield in cows was in the range from 574 to 599 kg. The difference in milk yield between these groups was 692 kg or 8.1% in favor of animals with live weight of 575-599 kg. An increase in cows’ live weight over 625 kg leads to a decrease in milk yield, which amounted to 2.3%. Changes in correlation are observed from a negative average value in cows with a live weight of less than 550 kg to a positive average value in cows with a live weight of more than 625 kg. In first heifers with live weight from 575 to 599 kg, a very low positive interrelation between live weight and milk yield per lactation was recorded (0.04)