The evaluation of a standardized commercial cutting technique for determining breed differences in carcass composition

SUMMARY Data for 383 steer carcasses from the first 3 years of the Meat and Livestock Commission's Beef Breed Evaluation programme were used to evaluate a standardized commercial cutting technique for estimating breed differences in carcass composition. The sample included carcasses from cattle out of Friesian, Hereford × Friesian and Blue-Grey dams by sires of the main traditional British beef breeds and by Charolais, Limousin and Simmental sires. The left side of each carcass was divided into 14 standardized commercial joints which were deboned and trimmed of fat to a fixed level (commercial cutting); the other side was jointed in the same way and each joint fully separated into lean, subcutaneous fat, intermuscular fat and bone (full separation). Breed means for characteristics obtained by commercial cutting were adjusted to equal carcass subcutaneous fat percentage (SF) estimated by visual appraisal, while those for full separation characteristics were adjusted to equal SF obtained by tissue separation. Breed differences in deboned fat-trimmed joints (saleable meat) as a percentage of carcass weight were in good agreement with those for carcass lean percentage (between-breed correlation, rb = 0·92), as were those for saleable meat to bone ratio and lean to bone ratio (rb = 0·91). There was a poorer relationship between fat trim and separable fat (rb = 0·62) but there was little breed variation in these characteristics at equal SF. Breed differences in the percentage of total saleable meat distributed in higher-priced joints were very similar to those for lean distribution in higher-priced joints (rb = 0·87).