Tasks and Selection Methods Briefly
Under the methods of breeding understand the system of selection of dogs for mating, taking into account the breed and linear affiliation.
The complexity of breeding tasks requires the use of various breeding methods: in some cases, they resort to the absorption of blood of an improved breed, in others they mate animals of one breed, and in others they mate individuals of different breeds.
Depending on this, there are three main methods of breeding dogs – purebred, crossbreeding and hybridization.
Pure breeding consists in mating animals of the same breed.
Crossbreeding is a method of mating animals of different breeds. Crossbreeding can be absorbent, introductory, reproductive, and variable.
Hybridization is a method of mating animals of various species, for example, a wolf – a dog, a jackal – a dog.
These breeding methods are also distinguished by biological nature. If at purebred breeding animals are obtained that are relatively of the same type in constitution, hereditary inclinations, then when crossing – heterozygous animals that differ from the original forms by increased variability. In dog breeding, the purebred breeding method is mainly used.
Purebred breeding is widely used to improve the number of already existing dog breeds. Its main goal is to preserve and improve the valuable qualities of the breeds.
The main task of purebred breeding in dog breeding is the preservation and improvement of dogs of this breed, its inherent qualities that meet the requirements of the breed standard. Pure breeding leads to an increase in the degree of homozygosity of dogs, since in this case identical genes are combined. Mating of closely related type of unrelated animals of the same breed also leads to an increase in the homozygosity of the offspring, but much slower than with inbreeding.
With high heritability of characters, mating of equivalent animals can be very effective for differentiating breeding material in quality, while low heritability of characters does not produce such an effect.
With thoroughbred breeding, it is sometimes required to introduce some heterogeneity or heterozygosity. Mating in this case, dissimilar animals usually leads to individuals with intermediate heredity and to some increase in heterozygosity. When perfecting dogs, mating (inbreeding) and unrelated mating (outbreeding) can be used.
The practice of cynological organizations indicates that purebred breeding is the main method of improving the qualities inherent in dogs of this breed. In this case, purposeful …