Evaluation of bulls-producers of the Holstein breed by the quality of the offspring

Relevance. Providing the population of the country with full-fledged food products of its own production is an important task facing the employees of the agro-industrial complex of the country. Such a product is milk. Milk is obtained mainly from dairy cows of productivity, the improvement of breeding qualities of which is due to the use of the global gene pool of the Holstein breed. The widespread use of Holstein bulls of various breeding breeds in the breeding of dairy cattle and the study of their influence on the productive qualities of daughters are relevant and have both scientific and practical interest.Methods. A comparison of the productivity of the daughters of four bulls-producers – Alta Bloomberg (country of origin – USA), Bourbon (Denmark), Norton (Germany) and Lisborn (Canada). Dairy productivity (milk yield, fat content, protein in milk) of cows was controlled by control milking, reproductive capacity – by the duration of the service period and the coefficient of reproductive capacity.Results. As a result of the research, it was found that the difference in milk yield between the peers of bulls-producers is unreliable, but there is a tendency for higher milk yields in the daughters of Alt Bloomberg, Norton and Lisborn, relative to Bourbon. In the milk of the daughters of Alt Bloomberg and Norton, the indicators for MJ in milk are higher (p ≤ 0.05–0.01), and Bourbon – MDB (p ≤ 0.01 in favor of the daughters of Bourbon). A significant difference in the age of achieving the first insemination was revealed between the groups of daughters of the evaluated bulls in favor of Bourbon daughters (Denmark) at p < 0.05–0.01. They reached the required body weight at the age of 12.9 months, which is 0.4–1.2 months faster. The daughters of breeding bulls have certain problems with reproduction. The coefficient of reproductive ability of cows is in the range of 0.89–0.94, which is below the optimal indicators for a good level of reproduction.