Selection traits of cows of different lines of Ukrainian black-and-white dairy breed

Linear farm animal breeding is an effective method of improving and consolidating breeds in purebred breeding, which contributes to forming an orderly genealogical structure of the breed. Further improvement and consolidation of economically valuable traits of breeds based on selection and selection are impossible without Linear breeding. Therefore, our work aimed to investigate the variability of breeding traits in cows of the Ukrainian Black-and-White dairy breed depending on the lineage. The research was conducted in the Vinnytsia region's State Enterprise “Alexandrovske” on firstborn and adult (III lactation) cows. Groups of animals belonging to different lines were formed to study the influence of linear affiliation on the variability of breeding traits of cows. Lines to which at least three breeding bulls belonged and with at least ten daughters were taken into account, with at least three daughters from one bull. In the control group of cows by retrospective analysis of zootechnical accounting data over the past ten years studying the dynamics of live weight during rearing at a young age (newborns, 6, 12, and 18 months), reproductive capacity (age and live weight at first calving, duration of first service period), milk productivity (yields, fat content in milk and the amount of milk fat). It was found that the economically functional traits of cows depended on their linear affiliation. The highest live weight of newborns and at the age of 18 months, the average daily gain at the age of 6–12; 12–18, and 0–18 months, the most extended service period after the first calving, and the highest milk yields and milk fat yield for the third lactation were characterized by animals of Eleveishn 1491007, live weight at six months – H. T. S. Khaneve line 1629391, at 12 months – Starbuck line 352790, average daily increments from birth to 6 months of age – line H. T. S. Khaneve 1629391. The last one was also marked by the highest live weight, the oldest age at first calving, and the shortest duration of the first service period. The lowest live weight and the youngest age at the first calving and the highest yields and milk fat yield for the first lactation were observed in the firstborn of the Chif 1427381 line. Depending on lactation, the strength of the line's influence on yields was in the range of 7.2–12.6 %, fat – in the range of 7.9–12.0 % at P < 0.01–0.001. Linear affiliation significantly (P < 0.01) affected the fat content in milk during the first lactation, and for the third lactation, the effect was incredible.