PRODUCTIVITY OF THE HOLSTEIN FIRST-CALF HEIFERS OF DIFFERENT ORIGIN, TAKING INTO ACCOUNT HOUSING AND FEEDING CONDITIONS
Dairy cattle breeding in Russia should be competitive in foreign and domestic markets. The development of the industry is ensured by the formation in various regions of a wide network of large specialized dairy complexes equipped with modern high-tech equipment, staffed with highly productive cattle, and implementing innovative milk production technologies. The formation of the broodstock of dairy complexes is carried out, as a rule, due to the import of livestock of highly productive Holstein cattle. Studies by a number of scientists have found that animals imported from abroad have problems adapting to other specific conditions of housing. Therefore, the study of the adaptive abilities of imported livestock is of scientific interest. As the number of Holstein cattle raised in Russian farms and complexes is increasing in each region, a comparative assessment of the productive and breeding qualities of imported and domestic cows is relevant, taking into account the origin, breeding zone and age. In addition to improving livestock conditions and breeding methods in dairy complexes, modern methods of improving animal feeding diets are used, inter alia the inclusion of probiotic additives in the diet. The article presents the results of the evaluation of the milk productivity of imported (Hungarian and Danish) and domestic first-calf heifers from different regions in modern dairy complexes with intensive milk production technology. It was established that Holstein cattle of different origin is characterized by high milk productivity and good adaptation to conditions of housing and feeding, and the existing differences in the level of productivity are obviously related to the specific local conditions of the region and technology. In OOO RAO Narovchatskoye (LLC), milk yield for 305 days of lactation in Hungarian first-calf heifers was 13.7 % more than in Russian cows (p ≤ 0.001), the mass fraction of fat in milk was 0.15 % (p ≤ 0.05), and the mass fraction of protein in milk was 0.18 % (p ≤ 0.001). At OOO Green Agro-Sakhalin (LLC), the milk yield of first-calf heifers of domestic origin was 3.1 % higher than that of the herdmates from Denmark. However, no significant difference between the groups was revealed. According to the mass fraction of fat and protein in milk, no significant difference between the groups was noted. The productive potential of the studied livestock has not yet been realized by any group of animals. The use of the probiotic preparation Vetosporin-Active showed that in the cows of the experimental group, the milk yield for lactation increased by 6.7 % (p <0.05) in comparison with the control group. No significant differences were found in the content of the mass fraction of fat and protein in the milk of cows of the experimental group.