DAIRY PRODUCTIVITY OF COWS OF UKRAINIAN RED-AND-WHITE DAIRY BREED OF DIFFERENT GENOTYPES IN NATURAL AND CLIMATE ZONES OF UKRAINE

Abstract

Introduction. The development of modern dairy farming is inextricably linked to the increase in the genetic potential of livestock productivity and its implementation in specific production conditions. In order to implement the plan, it is necessary to implement modern breeding methods and create such operating conditions for livestock, under which their biological features will be characterized by stability, and the resources involved in the production of dairy products will be profitable. In such a situation, it is considered relevant to determine the effectiveness of selective crossing of Ukrainian Red-and-White Dairy and Holstein cattle with the aim of creating a highly productive population adapted to breeding in the appropriate natural and climatic zone of Ukraine. Research materials and methods. Evaluation of the influence of the conditional blood of the Holstein breed and the natural and climatic zone of Ukraine on the milk productivity of cows of the Ukrainian Red-and-White Dairy breed was studied based on the zootechnical records of 18 herds of the Forest-Steppe zone, 3 herds of the Polissia and 3 herds of the Steppe. The experimental cows of each natural and climatic zone were divided into 6 genotypic groups, depending on the conditional proportion of blood according to the Holstein breed: Group I – 50% and less (low blood); II – 50.1–62.4%; III – 62.5–74.9%; IV – 75.0–87.4%; V – 87.5–96.7% and VI – 96.8% and more (high-blooded). We analyzed the milk productivity of cows that had dated information for the completed I–III lactation. We took into account the number of cows not lower than the requirements of the standard of the Ukrainian Red-and-White Dairy breed with calving during the years 2005–2020. Research results. Monitoring the milk productivity of the Ukrainian Red-and-White Dairy breed made it possible to reveal some differences between animals of different natural and climatic zones of their exploitation and heredity according to the Holstein breed against the background of the reliable influence of the studied factors. In the first-borns of the forest-steppe zone, the increase in productivity with the increase in the conditional share of Holstein blood is typical for all genotypic groups, except for the second one. First-born cows close to the Holstein breed in terms of milk yield reliably outnumbered representatives with lower conventional blood by 316–1690 kg. Subject cows for 305 days of the second completed lactation responded positively to the increase in heritability of the Holstein breed in their genotype within the range of 440–1847 kg, which was reflected in a significant difference. During the third lactation, the existing curvilinear relationships between the milk yield of cows of the first three genotypic groups leveled off further and ensured a steady increase in productivity with an increase in the heredity of the Holstein breed. Regardless of the genotype of the cows, their yield increased with increasing age in lactation. In the conditions of Polissia, the first-borns of the Holsteinized population of the domestic breeding group VI had the highest milk productivity, which exceeded the analogues of other genotypes by 256–1936 kg (p < 0.001), according to the general trend of improving productivity with an increase in the conditional blood of the Holstein breed. Crossbreeds close to the Holstein breed produced 168–1502 kg of milk more during the second lactation than animals with less blood. In the natural and climatic zone of the Steppe, cows of all genotypic groups, except for those close in heredity to the Holstein breed due to their absence, were characterized by a significant differentiation of milk, and both during the first and second-third lactation. First-borns, except for animals with conditional blood of 62.5–74.9%, increased their yield with an increase in the heredity of the Holstein breed in their genotype. A similar situation was noted in the second lactation, with the only difference that the decrease in milk yield, compared to low-blooded women, was 50.1–62.4% in women with conditional blood. A completely different trend in terms of milk yield, compared to the two previous lactations, was found in full-aged cows, where the increase in conditional blood for the improving breed by more than 50.1% was accompanied by a decrease in productivity. Low-blooded cows of the I genotype group in the third completed lactation exceeded individuals with higher conditional blood of the Holstein breed (II–V groups) by 201–735 kg. To confirm the influence of cow genotype on milk productivity, one-factor analysis of variance was used, which proved that the fertility of cows of the Ukrainian Red-and-White dairy breed during the I–III lactation was 7.7–9.3% (p < 0.001) dependent on the conditional Holstein blood breed. Although the determination of milk fatness by the genotype of cows was somewhat smaller – 4.4–6.3%, it was also highly reliable. Similarly, the influence of the natural and climatic zone of livestock keeping on the fertility of cows of the first to third lactation, respectively, was 2.5–3.4% (р < 0.001) and the fat content in milk was 2.1–4.8% (р < 0.001). Conclusions. Cows of the Ukrainian Red-and-White Dairy breed of different genotypes during the I–III completed lactation in the conditions of the natural and climatic zone of the Forest Steppe were characterized by higher productivity compared to the Polissia zone. The influence of the natural and climatic zone of exploitation of cows on their yield during the first to third lactation was reliable.