MILK PRODUCTIVITY OF DAUGHTERS OF DIFFERENT SIRES OF THE HOLSTEIN BREED

The productive and breeding abilities of animals are largely determined by their origins. Sires, especially those belonging to the leading lines of the Holstein breed, have a great impact on the cow production in dairy cattle breeding. According to the purpose of work, the article present data of a comparative assesment of the Holsteins breed's cow productivity of milk of different sires' daughters of Wis Burke Ideal 1013415 line. The research was conducted under the conditions of intensive technology of a modern dairy complex with a cow population of more than 13 ths. animals, total production of 175 ths. tons and milk yield per cow of 11900 kg of milk. The results of the research prove the valuable breeding abilities of the sires, which are confirmed by the high milk productivity of their daughters. In two completed lactations the milk yield of the daughters (n = 510) of four sires averaged from 8964.1 kg to 10171.5 kg of milk. The mass fraction of fat in milk ranged from 3.59 to 3.84 % and the mass fraction of protein – from 3.12 to 3.18 %. When comparing daughters of different bulls in terms of milk production, there is a reliable difference in individual key indicators for a full lactation and 305 days of lactation. Concerning the lactation period, there are differences in the sires' daughters productivity: all daughters of the Wis Burke Ideal 1013415 bulls are characterized by high productivity qualities. The dairy output level indicates purposeful breeding and selection work with the herd