Comparative study of the influence of type belonging on the productive and biological indicators of first-calf heifers

Abstract

In modern economic conditions, the most profitable livestock industry is dairy farming. One of the main conditions ensuring an increase in milk production is the acceleration of the rate of breeding work aimed at creating herds whose animals meet modern requirements for the efficient use of feed, are characterized by a high level of early maturity and the maximum realization of their genetic potential. The comparative assessment of weight and linear characteristics of heifers of different genotypes presented in the work indicates the compliance of the indicators with the standards of breed types. All the animals had a pronounced dairy type. In terms of live weight, the Yenisei type heifers of red-motley breed during the period of fertile insemination were superior to the peers of the Krasnoyarsk type of black-motley breed by 2.2 and 2.1%. The insemination index in heifers of the first and third groups was significantly lower (by 0.26 and 0.31%) than in the compared animals. In the first lactation, the cows of the Krasnoyarsk type of black-motley breed from the third group were superior in milk yield to the cows from the fourth group by 285.2 kg of milk or by 4.9% (P> 0.99). The cows of the Yenisei type of red-motley breed of the first group were superior in milk yield to the cows from the second group by 126 kg of milk or by 2.5% (P> 0.95). The animals inseminated at the age of 16-17 months had the largest mass fraction of fat and protein in milk, regardless of breed.