Abstract
The aim of this study is to investigate the growth intensity in young sheep and its correlation with specific blood parameters across different genotypes. Experimental research was conducted on three groups of young rams, each comprising 20 individuals. The first group consisted of purebred Akzhaik meat-wool breed rams, the second group included crossbred rams derived from mating Akzhaik ewes with North Caucasian breed rams, while the third group consisted of crossbred rams obtained from the mating of Akzhaik ewes with Kuibyshev breed rams. The results revealed that the crossbred rams from North Caucasian and Kuibyshev breeds exhibited superior blood and serum parameters compared to their purebred Akzhaik counterparts, reflecting enhanced metabolic processes and redox reactions. This characteristic aligns with the principle of hybrid vigor (heterosis). At eight months of age, the crossbred rams in the first and second groups surpassed their purebred peers in hemoglobin content by 5.59 g/L and 12.64 g/L, total protein by 3.75 g/L and 6.46 g/L, urea by 0.20 mmol/L and 0.45 mmol/L, and glucose by 1.71 mmol/L and 1.46 mmol/L, respectively. The elevated activity of carbohydrate and protein metabolism, along with intensified redox reactions in the crossbred rams, contributed to a significant advantage in live weight, exceeding that of purebred rams by 3.75 kg and 5.79 kg. Therefore, in commercial enterprises focused on breeding the Akzhaik meat-wool breed, it is advisable to employ North Caucasian and Kuibyshev breed rams for industrial crossbreeding purposes.