The effects of sex condition, genotype and diet on bovine muscle fiber characteristics.

The effects of sex condition, breed type and dietary energy level on muscle fiber characteristics were examined at various ages and related to carcass characteristics and meat palatability. Cattle fed a low-energy diet had a significantly higher percentage of red muscle fibers, larger white muscle fiber areas and a greater percentage area of red muscle fibers than cattle fed a high-energy diet. A significant sex × breed within slaughter group interaction existed, which was complicated due to differences within breeds and sexes at different points of physiological maturity. Separate correlation coefficients for bulls and steers are shown that suggest strong directional interactions between carcass characteristics and meat quality, and muscle fiber characteristics.