LACTATION FUNCTION OF FIRST-CALF HEIFERS OF HOLSTEIN BREED OF DIFFERENT ECOGENESIS IN THE CONDITIONS OF INTENSIVE TECHNOLOGY

Abstract

The largest contribution to milk production increase is made by large highly-technological complexes, occupied by animals of the Holstein breed, imported from Western European countries. It currently accounts for 26.47% in the dairy herd structure of the Russian Federation. In this regard, it is necessary to study milk productivity, quality characteristics and safety of Holstein cows’ milk produced in the conditions of industrial technology, which is the purpose of our research. The scientific experiment was carried out in the conditions of OOO Agroindustrial Complex Rus, the largest milk producer in Ryazan region. As a result, high milk productivity of first-calf heifers of Holstein breed, imported from the Netherlands, Hungary and own reproduction under intensive technology, was established. There are no significant differences in production of specified lactation. The milk of cows of the studied genotypes had a high concentration of dry matter and calorie content, as for the content of somatic cells, it met the established requirements of the European and national standards. The content of minor components of milk indicated the absence of ketosis (β-hydroxybutyric acid, acetone) and compliance of energy and protein in the diets of cows (urea). The highest realization level of PIC (parent index of cow) for milk yield was shown by first-calf heifers of domestic selection, as the most adapted to local conditions, and the lowest - analogues imported from the Netherlands, with the highest PIC for milk yield. Their realization level of productive potential of milk yield was lower compared to the first-calf heifers of Hungarian and domestic selection, respectively, by 14.8 (P<0.001) and 20.1% (P<0.001), the coefficient of lactation curve stability is less than in comparison with domestic peers by 2.3 (Р<0.01), and imported from Hungary by 1.3 (Р>0.05), which shows that the housing conditions do not correspond to biological status of the first heifers imported from the Netherlands.