The use of inbreeding in dairy cattle breeding

Abstract In cattle breeding during breeding season, great importance is attached to the selection of male and female pairs. The purpose of the work is to assess the effect of inbreeding on the milk production of cows of different genotypes. It was found that the main number of animals in the herd was obtained using remote inbreeding, which is 83.8%. The use of related mating led to a decrease in the age of the first calving by 0.3 months, a lactation period by 0.4, and a slight increase in milk yield by 78 kg with a decrease in the mass fraction of fat by 0.01% and protein by 0.02%, relative to outbred cows. A significant change in the productive longevity of animals obtained by outbred breeding and the use of a moderate level of inbreeding (P≤0.05) was noted. The effect of blood on Holstein breed on the productive qualities of cows was also established. An increase in blood level to 75-91% led to an increase in milk yield and qualitative indicators of productivity. Thus, the average milk yield in the group increased by 566 kg or 9.4%, while increasing the mass fraction of fat by 0.04% and protein by 0.04%. The best indicators of productivity within the genotype groups were established with a remote level of inbreeding and a genotype of Holstein breed 91-97% blood. In the future, when developing a breeding plan, it is necessary to take into account the fact that the best quality indicators of productivity, namely the mass fraction of fat and the mass fraction of protein are higher in cows with a genotype from 76 to 91% and a moderate level of inbreeding - 3.97% and 3.08%.