Influence of paratypical and genetic factors on milk productivity and duration of cows’ productive life in Smolensk oblast conditions

The authors have carried out the research in order to study the factors affecting milk productivity and productive longevity of cows of Sychevskaya, black-and-white and Holstein breeds in various economic conditions in order to develop the basics of conducting breeding process with these breeds in the Smolensk Oblast at the present stage. The novelty of the research lies in the fact that for the first time the article presents an intra - and inter-breed analysis of milk productivity and lifetime of cows of the Sychevskaya, black-and-white and Holstein cattle breeds, their characteristics depending on paratypical and genetic factors in current conditions of the Smolensk Oblast. The percentage of cows’ survival to manifestation of possible maximum productivity in the Sychevskaya breed is 32.2-0.7%, black-and- white is 36.7-3.2%, Holstein - 33.2-1.7%, that is, 63.3-67.8% of animals do not have time to realize their productive qualities. Studying the influence of the first insemination age on cows’ lifetime showed that the animals inseminated in the period of 7-24 months have the longest lifetime, starting from the 25th month, the lifetime gradually decreases. The calculation of phenotypic correlation between the age of the first fruitful insemination and productive traits for maximum and lifetime productivity showed a slightly negative relationship (r = -0.008 - (-0.12)) at p ≤ 0.001), i.e., with an increase in the age of the first fruitful insemination, the lifetime productivity decreases, but the maximum increases. This trend is typical for all the studied breeds. The practical significance of the research is to plan further selection process when working with the Sychevskaya, black-and-white and Holstein cattle breeds in current conditions of the Smolensk Oblast. The results can be used in developing programs for selective and breeding work with Sychevskaya and black-and-white cattle breeds in the Smolensk Oblast for 2023-2032.