PECULIARITIES OF SELECTION AND BREEDING WORK IN AMERICAN MINK POPULATIONS UNDER PUREBRED BREEDING AND CROSSBREEDING

Abstract

According to the results of a retrospective analysis of the breeding of
American mink for purebred breeding and crossbreeding of the animal husbandry
of the Cherkasy Regional Consumer Union, a study of the variability and nature of
the inheritance of selection traits by animals in a number of generations was
carried out, the breeding value was determined and the optimal schemes for the
formation of mink families were substantiated. The results of the study of the
genealogical structure of the brown mink population, obtained by crossbreeding,
show the presence of 168 lineages and 640 families. For minks of the brown color
type obtained by purebred breeding, the presence of 132 lines and 530 families,
which constitute the nucleus of this population, was confirmed.
It was established that, in the conditions of this animal husbandry, the
degree of realization of the genetic potential in the populations of fur animals,
regardless of the breeding method, is quite high at 89-98%. The maximum
investigated indicator was found for such a selection feature as body size 98.6-
97.9%. The minimum level of consolidation was found by the indicator of the size
of the white spot on mink fur, regardless of the type of breeding - 0.18-0.26 points.
The use of the BLUP-method of estimating the breeding value of male
breeders makes it possible to rank breeders according to selection and genetic
characteristics, and to select animals to improve the created population. The
breeding value index makes it possible to select for further reproduction animals
with the maximum value estimate. This indicator for the studied populations was
139-149 points and had a distribution close to normal.
The study of the level of phenotypic consolidation of offspring with different
options for selecting pairs in minks obtained by crossing shows that in minks
obtained by crossing the maximum values of phenotypic consolidation of offspring
were registered with the following combination options: AxA, AxB, BxA, BxB, CxC,
DxD, in which the level of phenotypic consolidation in offspring was 76-81%.
The analysis of the results of the pairing of pairs in minks obtained during
purebred breeding also proved the truth of the statement about the maximum
percentage of phenotypic consolidation of the stock when using a homogeneous
selection of pairs using improvers: AxA, BxA, BxB, CxC, DxC, DxD - 71-78%.