Abstract
The creation of breeds, intrabreed types and breeding lines is the result of targeted selection and breeding work based on the use of methods of selection, selection and evaluation of the hereditary qualities of animals. The formation of the new Akzhayik type of horses, as a rule, was carried out to some extent with the use of reproductive crossing with subsequent consolidation of desirable traits, and also occurred mainly due to differentiation within an already existing breed under the influence of directional selection for individual economically useful traits. Among the most important measures to ensure the development of horse breeding, it is envisaged to significantly increase the level of selection work to improve the breeding and productive qualities of horse breeds, the creation of new highly productive breeds, types, and lines of horses that meet the requirements of intensified agriculture. Breeding work in the West Kazakhstan region is based on the breeding and improvement of Kazakh horses of the Jabe and Kushum breeds. However, local Kazakh horses from certain areas of Kazakhstan are characterized by a small live weight, which in adult individuals averages 350-390 kg. Currently, the task of selection is to significantly increase their weight while preserving the valuable hereditary adaptive and productive qualities of Kazakh horses. The research and production work carried out in this direction shows that this task can be successfully solved by the method of intra-breed selection and breeding by lines and families. As a result of many years of scientifically based selection work in conditions of year-round pasture maintenance, highly valuable groups of horses have been formed - descendants of the stallions Baklan-II 21-79 and Sakazhal 55-82 at the Zhaiyk River.