LAUSR

Abstract The aim of the study was to identify the GH/HaeIII gene polymorphism and to determine its association with growth traits in Salsk sheep bred in the Southern region of the Russian Federation. The identification of the GH gene polymorphism was performed by the PCR-RFLP method using the endonuclease HaeIII for restriction of an amplified fragment. During the experiment, the AA, AB, and BB genotypes of the Salsk breed sheep were identified at a frequency of 57, 36, and 7%, respectively. The values of the weight at weaning, at the age of 9 months and the average daily gain of the ram lamb with the AB genotype exceeded the values of the these parameters of the ram lamb with the AA genotype by 0.92 kg, 10.67 kg, and 47.3 g, respectively. The carcass weight, the weight of meat, the slaughter weight, and the slaughter yield of the ram lamb with the AB/GH genotype were found to be more as compared with the parameters of the ram lamb with the AA/GH genotype by 4.97 kg, 1.83 kg, 4.83 kg, and 2.04%, respectively. The ram's AB genotype also caused a greater weight of heart and kidney by 75.21 and 75.44 g, respectively. Thus, the presence of a heterozygous AB genotype in Salsk sheep breed has a positive effect on the growth traits. The rams of the AB/GH genotype significantly exceeded the rams of the AA/GH genotype and were found to have the best meat productivity.