Index construction to comprehensively assess dairy cows

The purpose of the work is to construct an index for a comprehensive assessment of dairy cows. The object of research is the cows of the Yenisei intra-breed type of the red-and-white breed, having three completed lactations, bred in the breeding reproducer of JSC Tubinsk of the Krasnoturansk District of the Krasnoyarsk Region. To test the productive-technological index, a group of 501 heads was formed, which included cows of three lactations: the first - 380 heads, the second - 75 heads and the third - 46 heads. A formula for calculating the productive-technological index of cows is proposed. With the age of cows, milk yield increased from 6340 to 7028 kg. The mass fractions of fat and protein were 4.15-4.20 and 3.14-3.16 %, respectively. In the first lactation, the cows had the smallest measurements: height at the withers - 135 cm, chest depth - 77.2, oblique body length - 147, chest girth behind the shoulder blades - 192 cm, which is consistent with the physiology of animal development. With age, the cows became shorter-legged due to an increase in the depth of the chest, which led to a decrease in the long-legged index from 42.7 to 42.0; An increase in milk yield and a change in measurements led to a slight decrease in the productive and technological index with age - from 4.71 to 4.52, which can be used to predict the productivity of cows. The parameters for the formation of the structure of a herd of cows are determined, taking into account the productive and technological index: 5.01 and above - selection; 4.01-5.00 - the first production; 3.51-4.00 - the second production; 3.50 and less - alignment. Among the first heifers, the selection group included 37.6 %, and the first production group included 38.2 %. The proportion of animals included in the ranking group increased by the third lactation to 15.2 %.