The estimation of carcass composition in bacon-weight pigs

Abstract

Abstract Forty-two Large White pigs were cut into six sample joints which were approximately separated with a knife (butcher's dissection) into subcutaneous fat, muscle, and bone. This was followed by a full scalpel dissection to determine the percentages of subcutaneous fat, intermuscular fat, flare fat, muscle, bone, skin, waste, kidney, and glandular tissue present in each joint. Correlation coefficients were calculated between the composition of the joints as estimated by knife and scalpel dissections, and the composition of the whole carcass. In general very high correlations were recorded between the percentages of muscle and subcutaneous fat in the fully dissected sample joints and the whole carcass. The rib end and fillet end were considered to be the most promising sample joints for estimating these tissues. These sample joint dissections were less effective for estimating the remaining carcass tissues. Butcher's dissections of the whole carcass were closely correlated with the percentages of muscle, fat, and bone in the carcass, but barrows had 1.5% (P <0.001) more dissectible fat than gilts in carcasses with the same percentage of butcher's dissection fat. The accuracy of the jointing procedure was assessed by comparing the weights of joints from the right and left sides of the same carcass. The top shoulder and hand and spring appeared to be the joints most susceptible to cutting errors. Untrimmed joint weights were not found to be useful indices of carcass composition. A comparison was made between the effectiveness with which carcass measurement, specific gravity, and dissection techniques estimated carcass composition; and the place of each in carcass appraisal is discussed.