Development of a commercial price schedule for producers and processors of lambs

Abstract

Equations were developed to predict the weight of trimmed retail (bone-in) cuts, trim, fat and bone from 321 lamb carcasses, ranging in carcass weight from 4.8 to 26.8 kg and in fat depth at the GR site (12th rib) from 1 to 31 mm. For commercial application, the equations were developed using a multiple regression program with the predictors carcass weight and GR. All equations explained a large amount of the variation in component weights (r2 = 0.76-0.99). A time and motion study using 172 carcasses showed that the times required to butcher carcasses of low fat (score 1 and 2) were similar. Likewise the mean time taken to butcher score 3 carcasses was similar to that of score 1 carcasses. However, it took significantly longer (P<0.05) to butcher score 3 carcasses than score 2 carcasses, and score 4 and 5 carcasses than score 3 carcasses. In addition, the mean times taken to butcher score 4 and 5 carcasses were significantly different (P< 0.05). By using multiple regression analysis it was shown that carcass weight, fatscore, their interaction and the butcher all significantly affected the butchering time. The findings of this work are discussed as they apply to the commercial development of price schedules and show that, when based on yield, lean heavy carcasses are more profitable for processing.