Kazakh fine-wool sheep bred in semiarid and desert zones of the Kazakhstan South-East are most widely spread in the Republic. However, most sheep do not satisfy the respective requirements of the breed in terms of productivity and especially reproductive capacity. Consequently, increasing the breeding performance and yield of commercial lambs is one of the most urgent issues in fine-wool sheep breeding. One of the tasks for scientists and agricultural specialists is to develop efficient methods to increase the reproductive capacity of fine-wool sheep and preserve lambs to the age of one year, one of the ways to increase the breeding performance being the selection of polycarpous pairs intended to accelerate the breeding rate for the mentioned product.