The influence of age, sex and breed of cattle on their muscle characteristics.

In order to gain more knowledge of the systematic changes occurring in meat tenderness and colour of different breeds and sexes of growing cattle, a number of characteristics were studied in five different muscles of Afrikaner and Friesland bulls and steers between birth and 24 months of age. Muscle collagen content of bulls was higher at birth than at all other ages and solubility of collagen decreased markedly between birth and 16 months of age. Shear force increased between 8 and 16 months, partially coinciding with the decrease in collagen solubility. Collagen content of muscles was higher in bulls than in steers and solubility decreased markedly between 12 and 16 months, only in the case of bulls. Afrikaner muscles were more tender than those of Frieslands and had a higher content and solubility of collagen. Pigment content was higher in Afrikaner than in Friesland muscles and increased steadily with age in all animals. The results show that the biological differences found to influence muscle characteristics were particularly those of age and breed of animal.