Meat composition in genetically selected a control cattle from a serial slaughter experiment

Young bulls from an Angus yearling-weight selection herd (ASl) and from the contemporary control herd (ACO), differing in average slaughter weight by 16·8%, were allocated for slaughter on one or six occasions between 7·5 and 25 months of age. The M. longissimus lumborum from the left side of each animal was measured for cholesterol, fatty acid composition, and protein, fat and ash contents in both raw and cooked samples; the pH and tenderness were also recorded. All meat was generally lean, averaging 4% fat in raw samples and 2·4% fat in cooked samples. There was a trend, though not significant, for a slightly lower percentage of fat at a fixed age in raw and cooked meat from the AS] herd than from the A CO herd. There were no significant selection effects on cholesterol content or fatty acid content, in either raw or cooked meat samples. The pH was significantly, higher in meat from the ASl than the A CO herd, although the difference was small (0·11 units), and there were no significant herd differences in tenderness. Overall, the herd effects on chemical composition and tenderness were very small and unlikely to be detected by consumers.