The interrelation of holstein black pied cattle’s productive qualities by lactation

Abstract

Holsteinized Russian black pied cattle of the Ural type are bred in the Sverdlovsk region, which is represented by large highly productive animals with a high genetic potential of productivity. The purpose of the work was to study the productive qualities of Holsteinized black pied cattle with a high proportion of thorough-bredness in the Holstein breed and their interrelation. Milk yield per lactation increases reaching the maximum for the third lactation. The increase amounted to o 1409 kg or 14.9% relative to the first one. The study has found changes in milk quality indicators; the indicators fluctuated depending on lactation, yet a tendency to increase MFF in milk from the first to the third lactation was revealed. The highest indicators were shown in the second lactation. During this lactation, the highest milk protein content was observed – 3.26%. Due to the increase in milk yield and milk quality indicators, an increase in the amount of milk fat and milk protein per lactation is observed from 679 kg (1 lactation) to 782 kg (2 lactation). The correlation between milk yield and milk quality indicators being MFF and MFP varies depending on lactation. Mainly, with the exception of the first lactation and the interrelation of milk yield per lactation - MFP in milk was negative and amounted to 0.11. That is, with an increase in milk yield, there is a decrease in MFF and MFP in milk.