The genotype influence for duration of the productive use of cows and the reasons of its disposal
The results of studies on the life and productive use of cows of different genotypes Ukrainian black and white dairy breed are presented in the article. It was established that the life expectancy of laboratory animals averaged 1851 ± 28 days and duration of productive use - 1065 ± 26.8 days. With increasing of blood Holstein breed productive use of animals decreased from 1158 (in cows with a share of inheritance Holstein below 50%) to 979 days (75% or more-blood animals). The high variability of life and productive use of cows all genotypes (Cv = 26 - 53%) are found out, which indicates ample opportunity to select animals according to these characteristics. The largest herd of cows (30.1%) dropped out due to poor performance and dysfunction of reproductive ability (25.9%). 20.3% of cows dropped out of the herd because of the physiological old age, 14.6% - because of udder disease, 9.1 % - as a result of injury. Withdrawal almost half of the animals (49.6%) from the herd is the result of causal relationships. One such feature is the certain sequence of events in time: cause precedes consequence. It is determined that between cause and consequence is genetic connection. At a certain stage of development the cause generates consequence. In the breeding aspect it could be minimized by setting optimal in terms of duration and efficiency of economic use of genotype of animals that are in specific ecological conditions of the environment. Birth calves per 100 cows, the coefficient of reproductive ability and fertility index animals grew with age. In order to increase the number, maintaining good performance reproductive ability and relatively higher fat and protein in milk black and white cows in the future breeding Ukrainian black and white dairy breed genotypes should be used, in which the share of inheritance Holstein breed is not more than 75%. However, the economies of the region should focus on preventive measures to non-communicable diseases, improving animal welfare.