GROWTH AND DEVELOPMENT REGULARITIES AND EXTERNAL CONSTITUTIONAL FEATURES OF REPAIR YOUNG CATTLE BROUGHT THROUGH THE CROSSBREEDING OF UKRAINIAN BLACK-AND-WHITE DAIRY AND SWISS BREEDS

Abstract

Goal. To study the influence of interbreeding of Ukrainian black-spotted dairy cows with bulls of Swiss breeds on growth and development and exterior-constitutional features of repair young stock. Methods. Selection-genetic analysis, comparative, statistical. Results. Research and production studies were conducted on the basis of the breeding plant of SE "Pasichna" ICSGP NAAS "Starosinyavsky district of Khmelnytsky region on the population of purebred animals of the Podolsk factory type of Ukrainian black-and-white dairy breed (UCHRMP) and local animals obtained from crossbreeding bulls of the Swiss breed. According to the results of experimental studies in identical conditions of feeding and keeping young animals of the experimental groups, it was found that the highest live weight, both at birth and in subsequent age periods is characterized by local young animals. However, a significant difference between the groups of 12.9 kg (td = 2.15; P > 0.95) in favor of crossbreeds is observed only at the age of 18 months. When studying the absolute increase in live weight of experimental calves in the three-month dynamics of postnatal ontogenesis, which is an indicator of the intensity of animal growth, the advantage of local animals over purebred peers was also established. The largest significant difference in their favor is observed at the age of 7–9 months (3.1 kg, td = 2.29, P > 0.95). In all other periods of cultivation, the difference is not significant. Comparative characteristics of the degree of stress in the growth of animals, which was determined by the relative increase in live weight in the three-month dynamics showed that the most intensively growing animals of both groups from birth to 3 months of age (168.0–169.3%), then – with increasing age, the growth rate gradually decreases. A significant difference between the experimental groups, according to the above indicators, has not been established. The average daily gains in live weight of animals, for all periods considered, were higher in local animals. On average, from birth to 18 months of age, they were: local heifers 660 g, purebred – 637 g. External evaluation of the studied groups of heifers showed that purebred young at 18 months of age had the highest height at the withers by 1.2 cm, height in the buttocks – 1.4 and oblique length of the torso and buttocks, respectively, 0.8 and 0.7 cm compared to local young, but inferior to the latter in latitudinal measurements: chest width 1.2 cm, width in macula – 0.9 and width in the buttocks – 1.1 cm. In general, animals of both groups are well developed and have a harmonious physique. Conclusions. The results of the analysis of the dynamics of live weight of experimental groups of heifers, aged from birth to 18 months of age, show that local young animals obtained from crossing cows of Ukrainian black-spotted dairy breed with bulls of Swiss breed have slightly better performance than peers of purebred animals . However, the difference between the groups is in most cases unlikely. External evaluation of the studied groups of heifers showed that purebred young for all considered periods, from birth to 18 months of age, have higher indicators in height at the withers, height in the buttocks and oblique length of the torso and buttocks, but inferior to local in latitudinal measurements : chest width, width in macula and width in the buttocks. Thus, it can be argued that when using crossbreeding of Ukrainian black-and-white dairy cows with bulls of Swiss breed, the obtained young animals have slightly higher rates of growth and development, which will further positively affect the size and quality of milk productivity, reproductive capacity and duration use of cows herd.