BIOLOGICAL BASIS OF THE APPLICATION OF THE HETEROSIS EFFECT BY BREED-LINE HYBRIDIZATION AND INDUSTRIAL CROSSING IN PIG BREEDING (review)

Goal. To summarize the biological features and results of the application of the heterosis effect through the analysis of organizational and methodological approaches to the formation and implementation of systems of breed-line hybridization and industrial crossing in pig breeding and other industries. Methods. Domestic and foreign sources of literature on the subject of research and their chamber analytical analysis. The results. Modern industrial pig breeding is based on the application of industrial crossing and breed-line hybridization. These two methods of breeding are used to obtain in the offspring those advantages provided by the manifestation of the biological effect of heterosis for the combination of the productivity indexes of the parental forms of pigs selected for a certain group. To ensure such a system, the pig breeding industry is divided into two main components - breeding and commercial. The selection of intermediate parental forms (or the first parental forms) is subject to higher requirements, because the manifestation of the effect of heterosis according to the group of signs of the reproductive capacity of sows must be ensured, and selection should be directed according to the growth rate of the young pigs. The final form in crossbreeding and hybridization systems are the so-called terminal boars. Conclusions. A review of literature sources regarding the generalization of the features and results of the application of the heterosis effect through the analysis of biological and organizational-methodical approaches to the formation and implementation of systems of breed-line hybridization and industrial crossing in pig breeding and other industries indicates sufficient plasticity of the system of used approaches. For any approach to the causes and consequences of heterosis, one of the main, if not the key, the limiting factor in its practical implementation is the ratio between the costs of means and time for the organization of the process, on the one hand, and the increase in efficiency from its application, on the other. The developed general-methodical approaches to the organization of systems of industrial crossing and breed-line hybridization in pig breeding make it possible to obtain heterosis effects for a number of economically useful traits in accordance with the set requirements. Modern world trends to obtain a greater number of high-quality meat products can be ensured due to the use in pig breeding of individual parental forms and effective variants of the effect of heterosis in the systems of industrial crossing and breed-line hybridization. The developed models for assessing the breeding value of pigs should take into account the biological features of the inheritance of economic and useful traits during breed-line hybridization and industrial crossing, as well as the predicted effects of heterosis on a number of economically valuable characteristics of pigs.