PRODUCTIVE AND REPRODUCTIVE QUALITIES OF HOLSTINIZED BLACK – AND-WHITE COWS

The article presents a comparative assessment of the milk productivity, reproductive qualities and productive longevity of Holstein cows of the black-and-white breed, depending on the first insemination of heifers and their linear affiliation. The optimal age of fertilization was established, taking into account the live weight and the duration of economic use of Holstinized black-and-white cows in the conditions of a peasant farm. A comparative analysis of the exterior of cows found that the optimal age for the first fruitful insemination of Holstein heifers of the black-and-white breed is 16-17 months, that cows with the age of the first insemination of 16-17 months to the third lactation came with higher indicators of linear evaluation. The economic efficiency of increasing milk productivity, reproductive qualities and productive longevity is determined depending on the age of the first insemination and the linear affiliation of Holstein cows of the black-and-white breed of cattle in the Almaty region. Keywords: reproduction, longevity, milk productivity, age of the first calving, insemination, live weight of cows, service period, dry period, blood oximetry, protein composition of blood serum.