FEATURES OF SELECTION AND BREEDING IN POPULATIONS OF SILVER-BLACK FOX AND POLAR FOX CAGE BREEDING

Based on the results of a retrospective analysis of the breeding of the silverblack fox and the polar fox of the animal husbandry of the Cherkasy RegionalConsumer Union, a study of the variability and nature of the inheritance ofbreeding traits by animals in a number of generations was conducted, the breedingvalue was determined and the optimal schemes for the formation of families of furanimals were substantiated. The results of studying the genealogical structure ofthe polar fox population confirmed the presence of 25 lineages and 110 families.For the silver-black fox population, this indicator was the presence of 37 lineagesand 120 families, which constitute the core of the population.In the conditions of this animal husbandry, the degree of realization of thegenetic potential in the populations of fur animals is a high level of this indicator -87.1-95.0%. The maximum values of this indicator are noted for quality indicatorsof fur, since the variability of this feature between generations is insignificant. Ahigher difference was traditionally observed for the body size indicator and forsuch an indicator of reproductive capacity as fecundity of females - 87.1-88.0%.The latter in the descendants was 0.28-0.68 goals. lower than the similar value forherd and pedigree, respectively.It was established that in the vast majority of cases of growth of theindicator, the calculated coefficient increased in the first generation relative to theparent herd and slightly decreased in the next generation, which may be due to ahigher level of variability of traits caused by genetic splitting of the trait in the nextgeneration.The maximum values of phenotypic consolidation were registered accordingto the body size indicator - 0.64-0.88 points. The minimum value was registered forthe population of polar foxes, respectively, the maximum value of the indicator wasregistered for the first generation of silver-black foxes.The progenitors of the lines in the polar fox population were characterizedby a fairly wide range of the breeding value index - 39-146 points. The main shareof breeders (10.61-23.48%) had a score within 139-144 points. For female headsof families, this indicator was: 14.72-35.85% - 141-143 points, in general, therange for the indicator of tribal value was within 139-146 points. The establishedindicators for the silver-black fox population have a distribution of the share ofbreeders and progenitors close to normal. Among males participating in theselection process, the maximum share of animals 10.81-21.62% had 141-144 points according to the evaluation results, for females this indicator was registeredfor animals evaluated 139-14 points (10.0-28.3 %).For polar foxes, the maximum coefficient of phenotypic consolidation ofyoung (77-81%) was registered with the following variants of the combination ofpairs - AxA, BxB, CxC, the minimum (62%) with heterogeneous selection - CxA,respectively. A similar trend was observed in the population of silver-black foxanimals, the maximum values of consolidation of young by a set of traits wereregistered in animals whose parents, according to the results of the evaluation,were combined in the following variants: AxA, BxB, CxC, the coefficient ofphenotypic consolidation – 72-83%. The minimum values were recorded with aheterogeneous combination of pairs - 62-70%.