Nutritional and energy value of muscle tissue of bulls of different genotypes
The influence of the genotype of bulls on the chemical composition of muscle tissue, the concentration of energy in it and the energy value of all muscles of the carcass was studied. The object of the study was bulls of the red steppe, Simmental and Kazakh white-headed breeds. It was established that when slaughtered at the age of 18 months, the young of the Kazakh white-headed breed surpassed the peers of the red steppe and Simmental breeds in terms of the mass fraction of dry matter in the longest muscle of the back, respectively, by 2.54 and 1.30 %, extractable fat - by 0.47 and 0.20 %, protein - by 2.00 and 1.05 %. The Simmental bulls outnumbered the Red Steppe bulls in terms of the analyzed parameters by 1.24; 0.27; 0.95 %. Gobies of the Kazakh white-headed breed were characterized by the maximum absolute mass of extractable fat and protein in the muscle tissue of the carcass, the young of the Red Steppe breed were characterized by their minimum yield. This determined the intergroup differences both in the concentration of energy in 1 kg of muscle tissue and in the energy value of all the muscles of the carcass with the leading position of the bulls of the Kazakh white-headed breed. Gobies of the Red Steppe and Simmental breeds were inferior to them in terms of the value of the first indicator by 526.3 kJ (11.96 %) and 258.2 kJ (5.53 %), respectively, the second - by 221.25 MJ (32.94 %) and 38.38 MJ (4.49 %). The muscle tissue of the bulls of the Red Steppe breed was characterized by the minimum level of the analyzed parameters.