Growth and distribution of individual muscles in Double Muscled and normal cattle

• Published in: The Journal of agricultural science 1985-12, Vol.105 (3), p.479-490
• Main Authors: Shahin, Karima A., Berg, R. T.
• Format: Article
• Language: English
• Subjects: anatomy and morphology; beef bulls; beef synthetic; cattle breeds; distribution; genetic techniques and protocols; growth analysis; Hereford; muscle weight; muscles; statistical analysis
• ISSN: 0021-8596; 1469-5146
• DOI: 10.1017/S0021859600059347

Eighteen Double Muscled (DM), 18 Beef Synthetic and 18 Hereford bulls, serially slaughtered from approximately 250 to 800 kg live weight, were used to examine the influence of maturity type and Double Muscling on individual muscle growth patterns and distribution. Breed types differed significantly in the relative growth rate of five of the 95 muscles. Individual muscles grew and developed at relatively different rates with muscles associated with locomotion being early developing followed by those associated with structure or posture and finally those which respond to sexual maturation or luxury muscles which were late developing. Individual muscle growth patterns revealed an increasing disto-proximal gradient along the limbs and an increasing caudo-cranial gradient along the whole body. However, within any anatomical region considerable variations with well defined growth gradients were found for individual muscles. In the proximal region of both limbs increasing medio-lateral growth gradients were apparent. At the same total side muscle, breed types differed significantly in adjusted mean weights of 33 of the 95 muscles. When comparison was made at the same total side muscle, DM showed a range of hypertrophy of + 28% to -28% when compared with the more normal breed types. Muscular hypertrophy followed a disto-proximal gradient along the limbs and an inner–outer gradient across the muscle layers with the superficial and bulkiest muscles being the most hypertrophied. At the same total side muscle, DM had heavier expensive or luxury muscles than normal cattle.