Lactation activities of cows - as a factor of productive longevity

In modern market conditions, the development of animal husbandry is not only of great socio-economic importance, but also a stabilizer of the financial condition of the entire agro-industrial complex. In particular, dairy cattle breeding today remains one of the leading sub-sectors of animal husbandry and its development is of great importance not only in ensuring the food independence of the country, but also in the social aspect. In dairy cattle breeding, productive longevity is characterized by such characteristics as total life expectancy and the number of calves during life, and lifetime productivity is characterized by lifetime milk yield. The aim of the work is to analyze the milk productivity of cows for a number of lactation periods as a factor of the duration of their productive use. The research was carried out in the OS "Streletskaya" (a branch of the Federal Scientific Center of Legumens and Groat Crops). A sample was made from cows of black-and-white cattle of three different lines (V.B. Ideal line, M. Chieftain line, R. Sovereign line) from the 1st to the 5th lactation. Cows of the line V.B. Idial and R. Sovereign have gradually increasing and decreasing lactation activity, which allows the animals to be used more effectively and for a long time on the complex. The coefficient of variability of the protein mass fraction showed a fairly low threshold in the lines of M. Chieftain and R. Sovereign, which indicates that this indicator can be changed or increased only by applying selection techniques. In the V. B. Idial line, on the contrary, a high indicator is observed - 8%, which makes it possible to change it by regulating paratypical factors. A similar pattern is observed in the indicator of the coefficient of variability in fat content. The analysis of the milk productivity of cows of different lineages showed a gradual increase in milk productivity and its decline from the 4th lactation in all lines, which allows for a longer use of animals in the complex, provided that the technology of milk production is observed in accordance with the physiological.