Abstract
The article reflects the data of scientific research that can serve the practice of selection and breeding work under conditions of various forms of ownership, as well as the improvement of selection and breeding work and the technology of production of high-quality and competitive sheep products in the conditions of year-round use of the foothill-steppe and desert pastures of the south of Kazakhstan. The research of polymorphism systems of serum proteins of sheep's blood of different intra-breed types by gender and age groups revealed the presence of certain allele combinations and the ratio of transferrin and hemoglobin genotypes. It has been established that these animals have their own specific range of frequencies of occurrence of alleles and combinations of genotypes. Based on the results obtained, the possibility of using genetic blood markers in the early assessment of the productive qualities of animals has been established. As a result of scientifically based breeding methods, in the “Batai-Shu” LLP in Zhambyl region created a breeding australized herd of the South Kazakh Merino breed with a white wool yolk, a cut of washed wool of 3.1 kg with a yield of 48-50%.