Poslavska Y. The influence of different factors on the formation of milk productivity and efficiency of lifetime use of Ukrainian Black-Spotted dairy cows

It was comprehensively studied and obtained new data on the formation of milk productivity, duration and effectiveness of use of cows of Ukrainian Black-and-White dairy breeds, genetic and paratypic determination and variability of the indicated indices. Different strength and direction of connection between the investigated factors and indicators of dairy productivity and productive longevity of cows are established. The most significant influence on the formation of the milk productivity of animals was their linear affiliation, the productivity of female ancestors (especially parents' mothers), the chest girth, braid length of the trunk, the live weight at the first insemination and the first hotel, and on the indicators for productive longevity - yield for the best lactation and body measure of the the first-born cows. It was scientifically substantiated and elaborated breeding methods for the creation of highly productive herds of Ukrainian Black- and-White dairy breeds and methodical approaches on determining the optimal values of economically useful signs of animals. Taking into account the revealed links between various factors and indicators of milk productivity, duration and efficiency of life of cows use new criteria for the selection of animals per live weight during the period of cultivation, body measurements, indicators of reproductive capacity and productivity of female ancestors were proposed. The practical possibility of increasing the yield of cows milk for a significantly younger age of their first fertile insemination and first calving was established.