Гистоструктура двуглавой мышцы бедра у овец западно-сибирской мясной породы в постнатальном онтогенезе

Historically sheep breeding has been an essential part of the Russian economy, however mutton is produced primarily by adult sheep slaughtering and inconsiderable mutton percentage is produced from lambs under one year old. West Siberian mutton breed (Zapadno-Sibirskaya myasnaya poroda) of sheep was bred to produce high-quality mutton (Patent No. 54176). The creation of this breed was determined by the necessity to increase mutton performance of sheep under the adverse Siberian climate. These sheep reveal good reproductive features, and they are fast maturing and reveal high dressing percentage at early age. The quality induces of mutton performance include the microstructure of muscle tissue, its age-related growth and development, and the changes of muscle fiber diameter. The study of muscle tissue microstructure enables more complete and objective evaluation of meat product quality. The study of age-related muscle micromorphology of West Siberian mutton sheep is of scientific and practical value; the research data is used to determine the optimum slaughter age. The age-related histological features of muscle tissue in West Siberian mutton sheep have not been studied yet. Our study of biceps muscle of thigh in West Siberian mutton ram-lambs in postnatal ontogenesis has revealed the increase of muscle fiber diameter by 12 months: the diameter increases six-fold and muscle area increases twofold as compared to those of newborn lambs. The endomysium increases evenly with the age. The perimysium increases 5 times to the age of 6 months as compared to newborn lambs, but at the age from 6 to 12 months it decreases by 14.6 µm. It is concluded that the mutton of 12-months West Siberian mutton ram-lambs is of the greatest nutritional value.