The relationship between conformation and the yield and distribution of lean meat in the carcasses of British pigs, cattle and sheep: A review.

Information available on the value of conformation as a predictor of carcass composition in the British livestock population is reviewed, particular reference being made to recent Meat and Livestock Commission (MLC) trials using the visual conformation assessments employed in national carcass classification schemes. In mixed breed populations, the visual conformation assessments are positively related to lean to bone ratio and muscle thickness, although the correlations are generally low. Their relationship with carcass lean content depends on the effectiveness with which variation in fatness is eliminated since fatter carcasses tend to be given higher conformation scores. Conformation provides little information about the proportion of total lean occurring in the higher priced joints. The value of conformation in a mixed breed population depends to an important extent on its ability to identify breed differences in carcass characteristics. Although of some value in this respect, it is less effective than actual breed identification. Within-breed regressions on conformation are generally in the same direction as those in the mixed breed populations, although the precision of prediction is lower. The results indicate that conformation has little practical value as a predictor of carcass composition within breed.