TY - JOUR AU - L. M. Khmelnychyi AU - V. V. Vecherka PY - 2018/05/15 Y2 - 2024/03/19 TI - The effect of share hereditability of Holstein breed and methods for selection of economically useful traits of cows dairy cattle JF - Animal Breeding and Genetics JA - Anim. Breed. and Genet. VL - 55 IS - 0 SE - Breeding and Selection DO - 10.31073/abg.55.19 UR - https://abg-journal.com/index.php/journal/article/view/173 AB - Scientific research to study the influence of the share of hereditabiliy Holstein breed and methods of selection for economically useful traits of cows of dairy cattle has been carried out in the breeding farm of LLC "Agrofirma" Vladana" of Sumy region for breeding of Ukrainian Black-and-White Dairy and Holstein breeds.A retrospective analysis of the milk productivity traits of crossbreed by Holstein cows has been showed their dependence on the heredity of improving breed. In the process of absorbed crossing, fat content of milk of cows has increased by 0,14–0,27% against the background of growing milk yield. The mass fraction of fat varied depending on lactation in the range of 3,72–3,76% in the group of low consanguinity cows and 3,86–4,03% in purebreed Holstein animals. The increase in the hereditabiliy of Holstein breed did not affect the variability of protein, mass fraction of which is 3,13–3,15% in the purebred cows group, depending on lactation, which is 0,0–70,11% higher higher compared with low-consanguinity animals. The best indicators of duration of service period have cows with a Holstein bloodline of 50,01–75,0% according to all three lactations. In animals of other groups with the growth of heredity Holstein breed, service period also has been increased. The highest rates of service period with variability of duration of 126–189 and 131–142 days were found in cows with high consanguinity of Holstein 87,51–93,75% and purebred Holstein animals.Estimation of the first-milking cows for milk productivity has been showed a significant advantage of group of cows, from the intralinear selection of animals obtained from crossing the lines. A highly reliable advantage in their favor, has been determined by milk yield and total yield of milk fat and protein, was 589 (P < 0,001), 24,9 (P < 0,001) and 15,7 kg (P < 0,01), respectively.Comparative analysis of controlled groups of cows according to the second, third and best lactations has confirmed the best results obtained with intralinear selection, similarly in milk yield, of milk fat and protein. The advantage of these indicators has been preserved at the age of second lactation with corresponding difference, which is 351; 14,1 and 7,6 kg, the third – 501, 20,6 and 20,5 and the best – 564; 20,3 and 16,3 kg. Despite the prevailing tendency of cows obtained from intralinear selection, according to the traits of milk yield, milk fat yield and protein, by the data of evaluated lactations, a reliable difference has been confirmed only by the milk yield of better lactation at P < 0,05. Because with intensive culling of cows after the first lactation significantly reduced sampling and increased variability of traits.According to the results of absorbed crossing of cows of Ukrainian Black-and-White Dairy breed with Holstein sires, has been created a high-yield herd of dairy cattle. With the increase in conditional consanguinity of Holstein breed, it has been established that traits of milk productivity and duration of service period increase. The most effective according to the milk productivity traits for this herd is intralinear selection of bulls-sires in comparison with the cross-line. ER -