Productive qualities of black-motley cows depending on the blood share of Holstein cattle

In the course of studies, it was found that the greatest milk yield in the 305 days of the first lactation was made by crossbred black-and-white cows with a blood share of Holstein less than 50 %, which is 3.9 % more than the corresponding indicator for cows with a blood rate of 75 %, 5.5 % more (P ˂0,5) than cows with a blood rate of 50 %, 13.4 % (P˂0.01) more than blood with more than 75 % and 22.7 % more (P˂0,001) than purebred black motley cows. The duration of the service period of the cows of the experimental groups varies from 144 days to 179 days, which exceeds the zootechnical standards of the reproductive indicators of dairy cattle, leads to an extension of the length of the inter-hotel period and a decrease in the calves' output from the brood stock.