The evaluation of economically useful signs of the cows of different lines of black-and-motley cattle under the conditions of the Amur region

The research objective was to carry out the assessment of economically useful features of the cows depending on linear accessory in the conditions of the Amur Region. The research problems were to estimate dairy efficiency of the cows of various lines, morphological and functional properties of the cows’ udder. The information of primary breeding account was received from JSC “Agrofirm ‘Partizan’,” Tambov area of the Amur Region. The cows were analyzed according to the results of the scoring and the first three lactations. The herd was quite young 64.4 % of cows of the first and the second lactation, full-aged animals made 35.6 %. According to genealogical composition, the herd of cows belonged to four leading lines of Holstein black-and-motley breed: Vis Beck Aydial - 73.0 %, Montvig Chiftein - 23.0 %, Reflection Sowering - 3.0 and S.T. Roquit - 1.0 % of the total number of pro-boned cows in 2019. Based on the results of the appraisal, the group of bull-producing cows was allocated in the amount of 20 heads. This group included 4 heads with milk yield for the highest lactation of 11169 kg of milk with a fat content in milk from 3.23 to 3.59. Twelve heads were with milk yield from 8 057 to 8 787 kg of milk and fat from 3.39 % to3.95 %, as well as four heads with milk yield of 7 609-7 911 kg and fat content of 3.50-3.95 %. Desirable cup-shaped udder was found in 65 % of cows with milk yield of 6598 kg and a fat content of 3.51 %. The cows had distinct features of dairy cattle. As the conclusion of the studies it is necessary to mention that in order to increase genetic potential of milk fat in animal it is advisable to use the bulls from Montvig Chiftein and S.T. Rockit.