Comparative assessment of productive qualities of holsteinized black-and-white cattle by lines

Abstract

Abstract In Sverdlovsk region Holsteinized black-and-white cattle of the Ural type are bred. The herd is represented by large bodied, highly productive animals with a high genetic potential for milk productivity. The aim of the research was to study the productive qualities of Holsteinized black-and-white cattle with a high blood relationship to Holstein breed depending on the line, and correlation between milk yield and live weight of cows. The average milk yield for 305 days of lactation in cows of both lines was almost the same, and the difference between them was insignificant. However, when considering the change in milk yield within the groups, it was found that the group of Reflection Sovering cows featured higher performance indicators – from 8.376 to 14.706 kg of milk. The difference between low productive and high productive cows yield amounted to 6.333 kg or 43.1%. In Vis Back Ideal group of cows the difference was less expressed, and amounted to 5.367 kg or 40.4%. The coefficient of variability in the groups was within the range of 26-28%, which indicates significant fluctuations in milk yield. The yield of nutrients in milk (the amount of milk fat + milk protein) was at the equal level - 783 and 730 kg.