On the issue of the genotype influence on the cows’ productive qualities

The purpose of research is to study the influence of the genotype on the productive qualities of first-calf heifers. Tasks: comparison of the level of milk production for the first lactation, determination of qualitative indicators of milk production and study of lactation curves. The object of the study is cattle of the Yenisei type of the red-and-white breed and the Krasnoyarsk type of the black-and-white breed. The scientific and economic experiment was carried out in the conditions of the Krasnoyarsk Region. As a result of the study, the highest milk yield was observed in heifers of the Yenisei type of the red-and-white breed of both groups in comparison with the peers of the Krasnoyarsk type of the black-and-white breed by 495.3 and 330.1 kg, or by 9.2 and 6.5 %, respectively ( P ≥ 0.99; P ≥ 0.999). Due to the highest milk productivity, the maximum amount of milk fat and protein in cows of the Yenisei type of the red-and-white breed of the first and second groups was found to be 28.1 in comparison with analogues from the third and fourth groups in the first lactation; 14.1 (P ≥ 0.99; P ≥ 0.999) and 21.0; 8.5 kg (P ≥ 0.99), respectively. Heifers of the Yenisei type of the first and second groups were superior to their peers of the third and fourth groups in terms of such an indicator as the average daily milk yield per lactation, by 1.6 and 1.1 kg, or by 9.0 and 6.6 %, respectively (Р > 0 .95-0.99). Thus, insemination at the age of 14-15 months had a positive effect on the quantitative and qualitative indicators of milk productivity: milk yield for 305 days of lactation, mass fraction of fat and protein, amount of milk fat and protein, milk yield.