Rating assessment of Ayrshire bulls (foreign and domestic selection) used in breeding farms of the Vologda region

The article presents the rating assessment of Ayrshire bulls-producers (foreign and domestic selection) reproductive traits in the Vologda region. The study population under control of the Ayrshire breed includes data on 450 heads received from 11 bulls of foreign selection and 246 heads received from 11 bulls of domestic selection. The comparative characteristics of bulls-producers show that the bulls daughters of both foreign and domestic selection have approximately equal average age of the first fruitful insemination (17,3 and 17,9 months respectively), the age of the first calving (26,4 and 27,0 months respectively). The duration of the service period is 18 days shorter in the bulls’ offspring of foreign origin and is 126 days, which is close to the optimal values. At the same time the insemination index of the bulls’ daughters of domestic breeding is 1,4, which is 0,2 less than that of foreign bulls-producers. Based on the studies conducted it is possible to distinguish the 2 best bulls estimated by the complex of daughters’ reproductive features with a rating distribution: Napiper 9064929831 (Rcp 2.3) of foreign selection and Vulcan 1526 (Rcp 1.0) of domestic selection. The proposed rating method allows you to evaluate bulls-producers and select the best of them according to the set of daughters’ reproduction signs.