Milk productivity of cows-daughters of different sires of foreign breeding

Abstract

The widespread use of Holstein sires of different selections in the breeding of dairy cattle and the study of their influence on the productive traits of daughters is relevant and of practical importance. The purpose of the research was to study the milk productivity of cows-daughters of different sires of foreign breeding. The research was carried out in one of the breeding farms in the Sverdlovsk region for breeding Holstein black-and-white cattle. The object of the research was Holstein sires of diff erent breeding and their daughters. A comparison was made of the milk production of daughters of four sires: Alta Bloomberg (country of origin USA), Bourbon (Denmark), Norton (Germany) and Lisborn (Canada). It was found as a result of the research that the diff erence in milk yield between herdmates daughters of diff erent sires was statistically insignificant, but there was a tendency for higher milk yields in the daughters of the sires Alta Bloomberg, Norton and Lisborn, compare to the daughters of the sire Bourbon. In the milk of the daughters of sires Alta Blumberg and Norton, the mass fraction of fat in milk was higher (p ≤ 0,05–0,01), and in the daughters of the sire Bourbon, the mass fraction of protein was higher (p ≤ 0,01). Signifi cant differences were also revealed in the chemical composition of milk from cows-daughters of different sires. The results of the assessment on sanitary and hygienic indicators confirmed the high quality of milk. Indicators of bacterial contamination of milk and the presence of somatic cells in milk were low and met the requirements for premium milk. A significant difference was established in the increase in the number of bacterial and somatic cells in milk with the age of cows in daughters of the sires Alta Blumberg and Bourbon (p ≤ 0,05–0,01). In the milk of the daughters of the sires Norton and Lisborn, a statistically significant difference was obtained only for somatic cells (p ≤ 0,01 and p ≤ 0,001).