The relationship of milk productivity and reproductive functions of Holstein cows

Abstract

Relevance. Providing the population of the country with high–quality food products of its own production is the main task facing the employees of the agro-industrial complex of the country. One of these products is milk. The bulk of milk is obtained from cows of the dairy productivity direction. Currently, in the Sverdlovsk region, more than 75% of the total number of cattle belongs to the Holstein breed, created by the absorption of domestic black-and-white cattle by the Holstein. The study of economically useful signs of dairy cattle of the Holstein breed is relevant and has practical significance.Methods. The research was carried out in breeding reproducers for breeding Holstein black-and-white cattle of the Sverdlovsk region. The evaluation included all cows that completed the first lactation in 2020-2021. Milk productivity was assessed by control milkings, milk quality indicators: MJ and MDB in milk in an average milk sample from each cow — once a month in the dairy laboratory of “Uralplemcenter” LLC.Results. As a result of the conducted studies, it was found that the highest productivity indicators in cows were on the 3rd lactation — both for the entire lactation and for 305 days of lactation. Starting from the 4th lactation, there is a decrease in milk yields — from 0.3% (5th lactation) to 8.5% (8th lactation). Further, fluctuations in milk yields have been established in the direction of increasing or decreasing, which is explained by a decrease in the number of animals used in farms for a long time. Coefficient of reproductive capacity for all lactation (up to and including the 12th) stable and is 0.89–0.91, that is, there is a problem with the reproduction of breeding reproducers in dairy cattle herds. No relationship between reproductive functions and milk yield of cows has been established.