DEVELOPMENT OF THE MUSCLE SYSTEM IN BULLS DEPENDING ON GENOTYPE

Abstract

A study of the developmental characteristics of carcass muscles was conducted on Simmental and Black-and-White bulls and their first-generation crosses. At 18 months of age, a control slaughter of three bulls of different genotypes was performed: Group I - purebred Simmental bulls; Group II - crossbreeds of ½ Simmental x ½ Red Steppe; Group III - crossbreeds of ½ Simmental x ½ Black-and-White. When studying the development of muscle groups and individual muscles by anatomical regions, the left halves of the carcasses were dissected in accordance with the methodological instructions. To facilitate analysis of the material, muscles were grouped according to the joints they serve and their topographic location according to the generally accepted scheme. Muscle development was studied based on the absolute mass of individual muscles and muscle groups. Castrated bulls of Group III were found to have an advantage over their peers in Groups I and II in terms of total spinal column muscle mass, which was 217-772 g (1.43-18.30%), total shoulder girdle muscle mass, 1.45-0.51 kg (9.78-3.51%), chest limb muscle mass, 231-660 g (14.37-41.04%), pelvic limb muscle mass, 3.16-1.11 kg (9.78-3.45%), and overall muscle mass across the entire half carcass, 6.62-2.33 kg (9.79-3.44%).