The use of different selection methods for improving the herd of black-and-motley cattle in breeding factory

The aim of the research was to analyze the methods of selection in a breeding plant for breeding dairy cattle and develop selections for the next period. The tasks of the research consisted in studying genealogical structure of the herd and analyzing the productivity of cows depending on the lineage; identifying the best combinations for intraline breeding and cross lines and proposing effective matching methods. The research was carried out at a black-and-motley breed breeding plant in Tyumen Region. The object of research was black-and-motley cattle. When using the SELEX. Dairy Cattle”, the database of live cows was formed and analyzed. The research results were processed biometrically using the Microsoft Office software application. In the analyzed herd, animals were mostly represented by Holstein lines, more than 30 % of cows belonged to the lines of V.B. Aydial and R. Sovering, 27.6 % were represented by M. Chieftain animals. When analyzing the compatibility of the Poseidon line, it was revealed that with the bulls of the V.B. Aydial and M. Chieftain lines, a significant increase in the level of milk productivity was received, so the use of the V.B. Aydial bulls increased the milk yield by 17.2 %, the bulls of the M . Chieftain by 17.1 %; cross with the bulls of the R. Sovering line could be characterized as neutral. The main way of breeding cows of the VB Aydial line was intraline breeding, causing a significant decrease in milk yield by 5.1 %, but at the same time, the milk protein content increased by 0.02 %. The crosses of the VB Aydial line turned out to be ineffective. Since there were animals in the herd with ablood share of 25-50 % in the black-and-motley breed, it was possible to carry out backcrossing with the bulls of the black-and-motley lines of Poseidon and Annas-Adem. This would make it possible to preserve a valuable genotype of the Ural offspring, available at the enterprise, having only a fairly high productivity for the cattle of this group, but also characterized by strong health and long-term economic use.