ON THE INFLUENCE OF THE SELECTION MODEL ON COW PRODUCTIVITY
2021
Mukhtarova O.M. (Skryabin Moscow State Academy of Veterinary Medicine and Biotechnology)
The article explores the influence of different selection models on the dairy productivity of Holstein Black Pied cattle in acomparative aspect based on their comprehensive assessment over the entire period of use in the herd. For this purpose, the studyselected two groups of cows (100 heads in each) based on the principle of paired analogs by the date of the first calving in theinterval of up to one month. The first group included cows obtained by breeding three lines with maintenance for one of themthrough the mother's father, mother, and father, the second group included cows obtained by breeding different numbers of lines.Individuals of both groups descended from the same bulls of the same breeding value. A comprehensive assessment of animalswas carried out according to 9 indicators (live weight when grown at different age periods, basic body measurements, milkproductivity for existing lactation, and average indicators for a number of lactation). Statistically significant differences betweencows of two different groups were established by the following 11 indicators: the duration of the service period, the number ofmilking days and milk yield for the first lactation, the duration of the calving period in I and V lactation, the age of the secondand third calving, milk yield for IV lactation and for its 305 days, average milk yield for a number of lactation, milk yield forone day of the calving period.
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