The estimation of carcass composition in bacon-weight pigs

Abstract

Abstract The relationships between the composition and specific gravity of bacon-weight pig carcasses were investigated using carcass data from two fattening trials. In one trial bacon sides from 42 Large White pigs were fully dissected, and in the other bacon sides from 64 mainly crossbred pigs were minced and chemically analysed. The specific gravities of all six carcass joints were individually measured and correlated with their own composition and that of the whole carcass in Trial One, and with the composition of the whole carcass only in Trial Two. Specific gravity was strongly correlated with carcass composition, giving residual standard deviations between 1.47% and 1.75%. These residual standard deviations were further reduced by the inclusion of carcass measurements with specific gravity data in multiple regression equations. In both trials the correlation between whole carcass composition and specific gravity of the rib end was significantly higher than the corresponding shank end correlation. Variation in specific gravity was primarily dependent on variation in the fat content, with variation in bone content having a small effect in some joints, but not in the whole carcass. At the same specific gravity, significant differences in carcass composition were found between boar progeny groups within the Large White breed, and between litters of crossbred pigs. Sex differences had no effect on specific gravity measurements.