EXTERIOR-CONSTITUTIONAL FEATURES OF COWS DEPENDING ON AGE AND GENOTYPES

The purpose of the study is to identify the influence of Holstein breeders on the exterior features of improved red steppe cattle. To study the exterior features of cows, three groups of cows were formed, from which the main body measurements were taken at 2–3 months of the first, second and third lactations, body indexes were calculated according to generally accepted methods. Groups of experimental animals were characterized by different indicators of body measurements, which is due to the genotype and age characteristics. Holsteinized first-calf heifers were distinguished by higher values of height at the withers, which exceeded the cows of the control group by 1.7–3.8 %. Primary heifers of the control group and three-breed crossbreds of the first generation were characterized by similar chest depth values (P < 0.95) and were inferior to three-breed crossbreds of the second generation by 4.1 and 4.6 % (P < 0.95 and P > 0.95), respectively . An analysis of chest width showed that the use of Holstein sires on an array of red steppe cattle had an impact on the development of chest width. With age, there is some change in the proportions of the body of the experimental groups of cows. Compared with the first lactation, the indexes of stretchiness, massiveness, chest, boneiness and broad chest increased in the anglerized cows of the second lactation. During the specified period, the indexes of overgrowth, stretching, massiveness, chest and broad chest increased in Holsteinized cows of the first generation, while in animals of the second generation there was an increase in the indices of stretch, massiveness, chest and broad chest. Anglerized and Holsteinized crossbred animals are generally characterized by a pronounced type of dairy cattle. An assessment of the improved herds of red steppe cattle was carried out according to the conformation and constitutional features, differences were revealed in the exterior of crossbred cows, depending on the proportion of Holstein bloodlines.