Agerelated variability of the exterior and muscle tissue of young bulls of the Gray Ukrainian breed

Abstract

Goal. To study the peculiarities of growth and exterior indicators, fattening, and slaughtering quali­ties of bulls of the Gray Ukrainian breed, as well as the morphological composition of their carcasses. Methods. Generally accepted zootechnical, bioche­mical, and statistical research methods were used. Results. It was established that according to the growth indicators bulls of the Gray Ukrainian breed in all age periods met the requirements of the elite class; in terms of exterior, they have no deviations from the standard. Experimental animals showed high energy of growth on fattening. Thus, their live weight increased by more than 1000 g and reached an ave­rage of 387 kg at the age of 12 months. The formation of muscle tissue in bulls of the Gray Ukrainian breed took place within 30 months with a dynamic increase in energy value due to the faster growth rate of fat compared to protein. The slaughter yield at the age of 24 – 30 months varied between 58.1±2.18 and 58.9±2.27%, and the carcass yield was more than 54%. Intermuscular and intramuscular fat gave the beef marbling, juiciness, tenderness, aroma, and good culinary properties. The physicochemical properties of the muscle tissue of bulls (tenderness, losses during heat treatment, acidity, intensity of color) ensured high quality of beef. Conclusions. The Gray Ukrainian breed can be used by farmers of the Steppe zone of Ukraine in the breeding process, as well as, upon reaching 30 months of age, for the production of high-quality beef.