Рopulation-genetic parameters of selection of local families of volinian beef cattle

The development and promising use in the production of specialized breed is associated with clearly defined parameters of its structural formations (local types, lines, families), which are constantly in motion and change the breed in the desired direction. Therefore, the objective of the article is to analyze the population-genetic parameters of selection in local families. The material of the study was animals of the Volinian cattle breed of meat direction of productivity belonging to the breeding plant of LLC «Zorya», Kovel district, Volyn region. Eighteen local families have been formed, divided into three in six lines with a total livestock of 160 cows and 13 breeding bulls. The main parameters included in the study were phenotypic variability and correlation, inheritance and power of influence. Inheritance was determined by the method of doubling the correlation coefficient "mother-daughter", whereas the force of influence due to the ratio of factorial variance to total. The maximum and minimum values of live weight of heifers of local families at the ages of 7, 12, 15 and 18 months are respectively 183 kg… 197 kg, 283 kg… 305 kg, 342 kg… 357 kg, 390 kg… 415 kg. The coefficient of variation in the above-mentioned heifers of heifers obtained a low degree of variability not exceeding 8%. In families of Bulana 943 (7 months), Harna 536 (12 months), Kazka 433 (15 months) and Korona 2382 (18 months) received values of average degree of variability. The highest values of average daily growth of heifers were obtained from the following families: Verba 1536 (0-7 months - 810 ± 21.3 g), Palma 275 (7-12 months - 766 ± 47.7 g), Visla 1016 (12-15 months - 703 ± 22,8 g) and Korona 2382 (15-18 months - 802 ± 106,7 g). The variability in daily calf growth ranges from 8,2% in the period 7-18 months to 38,5% in the period from 15-18 months. The correlation between live weight and milkiness of cows and height measurement in the withers, duration of use and score was in all cases positive. From 72% to 83% of local families between the height at the withers and the live weight of full-grown cows, milkiness was low. It should be noted the local families of Korona 2382, Verba 1536 (height at the withers-milkweed), Kalyna 212 (live weight of cows-duration of use), Rozetka 1313, Visla 1016 (point estimate of the exterior live weight of cows). Regarding the force of influence, they have no significant effect on the selection traits of the mother and father line (1-9%) compared with the influence of mothers and fathers (52-90%). The problem of solving previously unanswered questions regarding the assessment of local families by economic usefulness, as well as their population-genetic parameters, makes it possible to analyze and carry out breeding work not only with lines, but also with local families.