Theoretical Foundations Of Breeding Animals (dogs) Along Lines

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Theoretical Foundations Of Breeding Animals (dogs) Along Lines
Theoretical Foundations Of Breeding Animals (dogs) Along Lines
Anonim

The main task when working with any breed is to improve the productive and breeding qualities of animals. Factory breeds are most successfully improved when breeding them along the lines. Such breeding, according to many scientists, is the highest form of pedigree work in pure-bred breeding. Any factory breed of a valley has a branched intra-breed structure, the main elements of which are lines, families, intra-breed ecological, factory and constitutional types. The more intra-breed differentiation in these basic structural elements is expressed in a breed, the more opportunities for obtaining animals of the desired type in a short time.

Boerboel, dog photo
Boerboel, dog photo

A factory breed is an ordered system of genotypically (that is, according to the totality of hereditary qualities) differing individuals… The hereditary differences of individuals are also associated with their phenotypic differences, or differences in all those features and characteristics that have formed in the process of development, including economically useful qualities. The desire to widely use the best animals in breeding work, in each case characterized by a different combination of valuable traits and significantly differing in heredity, is the basis for differentiating the breed into lines and families. Even with the improvement of highly specialized breeds, breeders are breeding for many traits, and it is practically very difficult, and often impossible, to combine these traits in one animal, especially if the traits are linked with each other by negative genetic correlation.

Therefore, it is necessary to confine oneself to only a few of the most important traits and create qualitatively unique groups of animals within the breed that steadily inherit precisely these traits. And the use of animals from such qualitatively different groups in the selection makes it possible to obtain individuals with new, more desirable combinations of traits and, thus, to solve the problem of general qualitative improvement of the entire breed.

Purpose of breeding animals along lines is not only to consolidate, but also to develop in the offspring the valuable features of the best animals, to obtain numerous groups of animals with a stable heredity and through the correct breeding use of these animals to ensure the improvement of the breed as a whole. According to a number of prominent scientists (D. A. Kislovsky, N. A. Kravchenko, and others), breeding along lines is a means of transforming the advantages of individual best animals into group advantages. At the same time, it is important to keep not only the individual qualities characteristic of the ancestor of the line, but a whole complex of advantages, the type of the ancestor and those advantages that the best queens mated with him possess, as well as the successor of the line. As a result of breeding along the lines, the pedigrees of the resulting animals are saturated with the names of the most prominent ancestors,whose heredity supersedes that of their mediocre or unfortunate partners. This contributes to a more stable hereditary transfer of valuable qualities to animals and the progress of the line in a certain direction.

Breeding along lines allows you to dismember the breed or its zonal type into separate unrelated groups of animals and plan the selection so as to exclude accidental related mating.

The scheme of kinship of descending descendants with the ancestor of the line, drawing picture
The scheme of kinship of descending descendants with the ancestor of the line, drawing picture

In the special literature, there are two expressions: "line breeding" and "line breeding"

Breeding along lines is a complex system of zootechnical work with the breed and its individual herds, based on lines. E. Ya. Borisenko (1967) understands breeding along lines as breeding a breed in several directions, leading to a qualitative diversity within the breed, and not as “line breeding” from one individual (from the ancestor of the line). He, like D. A. Kislovsky (1955) and N. A. Kravchenko (1957, 1987), believes that the lines play a service role, are only part of the breed as a whole and independently, outside the breed, cannot exist. The main goal is not to create and improve individual lines, but to improve the entire breed by breeding along the lines.

Therefore, the creation and improvement of individual lines pursues a subordinate goal.

However, when breeding animals along lines, it is necessary to skillfully work with each line separately. Therefore, one cannot but agree with N. A. Kravchenko (1973) that the expression "linear dilution" also has a right to exist. It should be understood as a system of work with each specific line, designed for a number of generations and representing a continuous chain of purposeful selections. It is with the skillful management of the line that the valuable heredity of the ancestor and his successors, as well as their mothers and outstanding females used in the selection of outstanding females, turns from an individual into a group, characteristic of a fairly large livestock of animals.

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