Quantitative estimates of lamb carcass composition 1. Sample joints

Abstract

SUMMARYInterrelationships between carcass composition and the composition of 7 different sample joints were studied in 83 purebred Clun Forest lambs slaughtered at approximately 80 lb. live-weight and ranging in carcass weight from 29 to 42 lb. Correlation coefficients between physically separated fat, muscle and bone in the loin and in the carcass were 0·96, 0·93 and 0·84 respectively (P < 0·01). Corresponding correlations for the best-neck (7–12 rib joint) were 0·94, 0·92 and 0·76 (P < 0·01). The leg and shoulder provided the best estimates of carcass bone. The usefulness of predictions of carcass composition is discussed in relation to the maximum probable errors associated with individual and group mean predictions of carcass composition based on sample joints and with reference to the accuracy of these indices under different treatment conditions. The 5% confidence limits on individual predictions based on loin composition were ± 2.22%, ± 2.44% and ± 1.62 % for fat muscle and bone respectively; indicating that this index cannot be relied on to reflect small differences in carcass composition between individual animals.