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.

The purpose of the article is to highlight the major life milestones and creative path of the recognized scientist in the field of animal husbandry, Doctor of Agricultural Sciences, Professor, Academician of NAAS M. V. Zubets. Research methods are general scientific (analysis, synthesis, classification), special historical (problematic-chronological, comparative-historical), biographical and source studies. The contribution of the scientist to the development of theoretical and methodological principles of breeding, selection, and biotechnology of reproduction of farm animals is substantiated. The important role of M. V. Zubets in the organization of domestic agricultural research work, in particular, in the formation of the Institute of Animal Breeding and Genetics of the NAAS was proven. The scientific heritage of the scientist is systematized, the priority of his research on the formation of a systematic concept of the breed, linear breeding, development of genetic, biotechnological, and technological bases of selection in animal husbandry, the actualization of the problem of conservation and rational use of biodiversity, etc. is substantiated. The contribution of M. V. Zubets to the formation of the modern theory and methodology of breeding in dairy and beef cattle breeding, the breeding of specialized breeds, and types of cattle is revealed. It is shown that among his scientist's methodological developments, the most significant is the method of creating the Ukrainian Red-and-White Dairy breed, which is the basis for the development of eight specialized domestic breeds of dairy and beef production directions. The program the scientific school activities and the achievements founded by M. V. Zubets were summarized.

The aim of the research. To conduct a comparative analysis of growth characteristics, productive qualities and reproductive capacity of dairy cows using purebred breeding and interbreeding in the herd. Маterials and methods of reserch. The study was conducted in the herd of the State Enterprise “Niva” on cows of Ukrainian Red- and Black-and-White dairy and Holstein breeds. The analysis included information on the growth intensity, reproductive capacity and milk productivity of 978 cows with the first calving during 2015-2021. Among the breeding herds of the Ukrainian Red-and-White and Black-and-White dairy breeds, a comparative analysis of selection groups from breeding "in-house", selective crossing with Holstein and crossbreeds of the first generation with Montbeliard breeds was carried out. The degree of influence of genetic and paratypic factors on the phenotypic variability of the considered traits was assessed by means of univariate analysis of variance with the calculation of Fisher's test and the indicator of the strength of influence based on the ratio (%) of factorial and total variances (sum of squared deviations). Calculations were carried out using the methods of mathematical statistics using the "STATISTICA-12.0" software package on a PC. Research results. A comparison of the growth of live weight of controlled heifers of different breeds shows a certain (0.3–5.6%) advantage of Ukrainian Black-and-White dairy animals over peers of Ukrainian Red-and-White dairy and Holstein animals of red-and-white color over same-breed Black-and-White heifers. The effectiveness of three selection options was compared in the breeding breeder for the breeding of Ukrainian Red-and-White dairy cattle. The advantage of purebred breeding ("in-house") compared to the further use of purebred Holstein breeders has been established. The intergroup difference was insignificant in terms of the reproductive capacity of first-borns. According to the quantitative indicators of milk productivity, there was a reliable advantage in cows for breeding "in-house". The most intensive increase in live weight of heifers, higher milk productivity and reproductive capacity of cows differed from the analyzed interbreed crossing with the Montbeliard breed.The highest intensity of growth of crossbreeds with the Montbeliard breed of animals provided the youngest age of first calving (by 49 ± 19.7 days (P ˂ 0.02) compared to counterparts from inbred crosses and by 75 ± 21.3 g (P ˂ 0.001) – from breeding "in yourself"). In terms of milk yield, the first-born offspring of the Montbeliard breed were superior to their peers from the inbred crossing by 577 ± 73.0 kg (P ˂ 0.001), in terms of milk fat output – by 20.5 ± 2.63 kg (P ˂ 0.001), protein – by 23.2 ± 2.75 kg (P ˂ 0.001). More intensive growth of heifers ensured a significantly younger age of first calving of Montbeliard crossbreds compared to counterparts from self-breeding by 75 ± 21.3 days (P ˂ 0.001), from inbreeding – by 49 ± 19.6 days (P ˂ 0.02). At the younger age of calving, the firstborns of the place were superior to their peers from breeding "in-house" in terms of milk yield in 305 days of lactation by 225 ± 216.1 kg (P ˃ 0.1), from absorptive crosses – by 391 ± 216.1 kg (P ˂ 0.1), according to the output of milk fat – by 11.1 ± 7.47 kg (P ˃ 0.1) and 17.2 ± 7.50 kg (P ˂ 0.05), respectively, protein – by 9.7 ± 6.55 kg (P ˃ 0.1) and 15.6 ± 6.58 kg (P ˂ 0.02). The higher milk productivity of the Montbeliard crossbreds was combined with the better reproductive capacity of the first-borns. According to the coefficient of reproducibility, they exceeded the analogues from breeding "in themselves" by 0.131 ± 0.072 (P ˂ 0.1), from selective crossing – by 0.086 ± 0.073 (P ˃ 0.1) for a shorter service period (corresponding to 75 ± 29.4 days, P ˂ 0.02 and at 60 ± 31.0 days, P ˂ 0.05) and the period between the first and second calving (respectively at 75 ± 29.4 days, P ˂ 0.02 and at 60 ± 31.0 days, P ˂ 0.05). Such an advantage of crossbred cows with the Montbeliard breed may indicate the manifestation of the heterosis effect. Conclusions. 1. The difference between the animals of the Ukrainian Red-and-White and Black-and-White dairy breeds and the Holstein breeds according to the economically useful traits taken into account was mainly insignificant and multidirectional, which reveals almost the same efficiency of their use. 2. With a successful selection of improvers, purebred breeding ("in-house") in herds of Ukrainian Red-and-White and Black-and-White dairy breeds shows higher efficiency compared to the further use of purebred Holstein breeders (receptive crossing). However, at present, this method becomes practically unavailable due to the lack of progeny-rated bulls of the specified domestic breeds with high breeding value. Therefore, for the future, the only possible selection direction remains is further cross-breeding of newly created domestic breeds with improvers of the Holstein breed according to the scheme of selective crossing and formation of an array of breeding cattle of the Holstein breed of Ukrainian selection due to the immediate need to restore the domestic bull breeding system and the mandatory re-evaluation of imported breeders in the conditions of Ukraine. 3. According to most of the considered characteristics, the superiority of crossbred cows with the Montbeliard breed was established. This indicates the manifestation of the effect of heterosis, which, according to theoretical expectations, cannot be preserved in subsequent generations. Therefore, the selection strategy is to create a purebred breeding breeder of the Montbeliard breed by selective crossing. 4. It was established that the degree of intergroup differentiation for most of the considered characteristics increases from the interbreeding difference to the difference according to the selection method and the highest difference between groups of half-sisters by father. The analysis of variance established that the pedigree determines 0.03–3.9% of the total phenotypic variability of growth intensity, reproductive capacity and milk productivity of cows, the selection method – 0.02–18.1%, and the highest influence (4.2–55.8%) gives descent according to the father. 5. The correlation analysis established the superiority of the additive component (50.2–60.4%) in the genotypic variance, which will ensure high efficiency of mass selection based on the productivity of cows for higher lactation to the breeding core. The relative variability of the sire's breeding value with the milk productivity of the daughters at the level of 10.1–13.5% confirms the selective feasibility of progeny assessment and the selection of identified improver bulls.