Efficiency of selection of highly productive dairy cows

Abstract

In breeding work, a special role is given to the production, cultivation and use of highly productive animals, which provide the maximum economic income in the dairy cattle industry. The task of the research was to study the biological and economic characteristics, the characteristics of the lactation activity of highly productive holshtinized dairy cows.The studied animal population with an average maximum lactation impact of 10,511 kg was divided by productivity level into 3 groups. As a result of the studies, it was established that for 5 years the productivity of herd cows is at a level exceeding 10 thousand kg of milk. There was also a significant advantage of group 3 animals over group 1 peers from 8 kg at the age of 10 months increased to 13 kg at the age of 12 months, earlier insemination and longer productive longevity. An analysis of the lactation activity of cows showed that already 1 lactation of cows of the 3rd group significantly exceeded the peers of the other two groups in terms of yield by 504 and 3023 kg. The inter-group differences in yield per 1 lactation were1.6 and 6.8%, according to the average yield, they increased to 6.6 and 16.6%, and at the maximum to 15.7 and 34.6%.Comparing the ratio of productivity of female ancestors of animals of three groups (the superiority of the maximum impact of the mother of the father over the maximum impact of the mother), it can be seen that animals of the 3rd group are obtained as a result of more homogeneous, and animals of the 1st group as a result of heterogeneous selection: the percentage of superiority is lower in them than in animals of the 1st group (38.8% and 57.3%).