He origin and breeding value of the breeding bulls from which cows with record productivity were obtained

In selection and breeding work with cattle for dairy productivity, it is important to select the best individuals and their effective use in populations. The purpose of the study was to study the origin, genealogical affiliation, genotype and breeding value of sires from which cows with record productivity were obtained. The study was carried out on 15 sires fathers of 20 record-breaking cows of the black and white breed of breeding farms in the Vologda region. Based on the results of studying the origin of bulls from which cows with record productivity were obtained, it was found that out of 15 sires, 9 bulls were imported and 6 were obtained from breeding farms of the Russian Federation. Four bulls born in Russian breeding farms have one or both parents of foreign origin.The majority (14) of the record-breaking fathers have from 94% to 100% Holstein blood in their genotype and belong to the genealogical lines of the Holstein selection. The genetic potential of the sires was realized by recordbreaking daughters by 101.9% 176.7%. Based on the results of calculating the selection differential, it was established that all bulls had a positive effect on the milk productivity of the studied offspring. Their daughters are superior in milk yield for the highest lactation of their mothers from 1052 kg to 9222 kg of milk. The study of the breeding value of bulls obtained from the results of a centralized assessment using the BLUP method showed that 12 out of 15 studied bulls fathers of record cows are improvers in terms of milk productivity. The study showed the significant contribution of foreign genetics to the production of highly productive animals in domestic herds. As a result of many years of breeding work, animals with high productivity potential have been created, which must be used to obtain competitive domestic breeding material.