Rating assessment of breeding bulls of the Kholmogorskaya breed in terms of reproductive indicators in foreign and domestic breeding

The article presents the results of rating assessment of breeding bulls of the Kholmogorskaya breed in terms of reproductive indicators in foreign and domestic breeding in the North-West zone of the Russian Federation. The studies were conducted on the basis of a rating developed in the Northwest Research Institute of Dairy and Grassland Economy. 765 daughters of 18 domestic breeding bulls and 14 of foreign breeding bulls were observed. The rating of breeding bulls is established on reproductive signs of daughters. The bull of domestic selection Elf 10363 exceeds the best bull of foreign selection Aiksaer107966005 on the insemination index by 0.2, and has a shorter service period. The service period of the daughters of Aiksaer107966005 is 26.1 days longer. Also, Elf 10363 showed better results than Aiksaer107966005 in the age of the first productive insemination and the age of the first calving on 0.8 months and 1 month.