COMPARATIVE EVALUATION OF DAIRY PRODUCTIVITY OF COWS DIFFERENT LINES IN THE CONDITIONS OF THE OREL REGION

Abstract

This article provides a comparative analysis of indicators of milk productivity and quality of the main lines of the Holstein breed cows in one of the pedigree reproducers of the Orel region – "ES "Streletskoye". Among the three evaluated lines, the best results were shown by Reflection Sovereign first-calf heifers, which exceeded in milk yield the first-calf heifers of the Montvi􀉫 Chieftain line by 13.6% and the first-calf heifers of the Vis Back Ideal line by 42.3% (P≤0.001). Milk production coefficients of first-calf heifers of the Montvi􀉫 Chieftain and Reflection Sovereign lines exceeded those of the Vis Back Ideal line by 27.1% and 42.0% (P ≤ 0.001). In turn, Reflection Sovereign first-calf heifers also exceeded first-calf heifers of the Montvi􀉫 Chieftain line by 11.7% (P ≤ 0.001). Similar results were obtained for the second and third lactations. In terms of AMF and AMP, the Montvi􀉫 Chieftain and Reflection Sovereign cows significantly exceeded Vis Back Ideal cows in 305 days of each of the first three lactations. In turn, Reflection Sovereign first-calf heifers outperformed the AMF and AMP of Montvi􀉫 Chieftain first-calf heifers. The highest positive correlation coefficients between the amount of milk fat and milk yield for 305 days of lactation were found in cows of the Vis Back Ideal line - from 0.36 to 0.90 (P≤0.05–0.001). Concerning the correlation between the amount of milk protein and milk yield for 305 days of lactation, cows of all studied groups showed high levels of interdependence, characterized by a high degree of reliability - from 0.45 to 0.99 (P≤0.01– 0.001). The total cost of base fat milk produced in 305 days of the first three lactations by Montvi􀉫 Chieftain and Reflection Sovereign cows (per head) exceeded the cost of milk produced by Vis Back Ideal cows by 87.7 and 144.1 thousand rubles, respectively.