Variation in the carcass characteristics of commercial British cattle

Classification records for 1,150,000 beef carcasses, a one-third sampleof those classified by the Meat and Livestock Commission between 1973 and 1976, were used to examine the variation in weight, fatness and conformation of commercial British cattle. The overall ratio of male cattle (steers and young bulls) to heifers was 2·35 and young bulls comprised 4% of male cattle. There were only minor changes in the carcass characteristics over the three-year period considered. Mean carcass weights for steers (S), heifers (H) and young bulls (YB) were 264, 219 and 236 kg, respectively. Carcass subcutaneous fat percentages (SF(e)) were estimated from the distribution of carcasses between fat classifications. SF(e) for the three sexes were 8·21 (S), 8·81 (H) and 6·24 (YB). Regressions of SF(e) on carcass weight (kg) were 0·031 (S), 0·041 (H) and 0·026 (YB). There were important differences in the characteristics of carcasses from abbattoirs in different regions of the country. Carcass weights for steers ranged from 248 kg (northern England) to 280 kg (northern Scotland). Cattle slaughtered in northern Scotland were also fattest: SF(e) were 9·51 (S) and 10·2 (H). Using classification records, together with results from MLC dissection studies, national waste fat production in 1976 was estimated to be 48,000 t.