Dairy productivity and efficiency of milk production of black-and-white cows of different thorough-bredness on the Holstein breed

The studies were carried out from 2018 to 2019 in a pedigree reproducer for the black-and-white breed "Streletskoye" - a branch of the Federal State Budgetary Scientific Institution FSC ZBK of the Oryol Region. We realized that the number of diluted lactations in groups of cows with thorough-bredness on the Holstein breed had significant differences. According to the indications, cows with a Holstein thorough-bredness from 51 to 75% were significantly inferior to cows in the control group, which had thorough-bredness in the less than 50% Holstein breed by 36%. 76-87.5% - by 46% and cows with thorough-bredness over 87.5% - by 60%. Cows of the second, third, and fourth groups significantly exceed the indicators of the control group in terms of the average specific weight, respectively, by 17.3%, 19.4%, and 19.5%. Groups by total number, respectively, by 28.9%, 35.5%, and 52.2%. The average milk fat by lactation in the groups of black-and-white cows with Holstein thorough-bredness of 51-75%, 76-87.5%, and more than 87.5% was higher than in the control group by 16.1, 18.5 and 19.5% respectively. The proportion of Holstein breed thorough-bredness with other scientific indicators of milk productivity was in the range of 8.25-13.24% and was due to a non-existent breeding point of view. The economic efficiency of milk production of black-and-white cows has sufficient thorough-bredness for the Holstein breed. Indicators of keeping cows with Holstein thorough-bredness in the range of 51-75% are significantly inferior to cows with thorough-bredness less than 50% by 225.0 thousand rubles. Similarly, cows from groups with Holstein blood of 76-87.5% and more than 87.5% yield in the control group by 276.2 and 412.4 thousand rubles, respectively.