Loin Area at Tenth and Last Rib as Related to Leanness of Pork Carcasses

Loin areas at the tenth and last ribs, percent lean cuts and percent loin for both right and left sides were studied on 23 carcasses. Differences between pigs were striking for all carcass traits studied, while differences between sides and the interactions were negligible. The loin area at the last rib averaged 0.43 sq. in. greater than that at the tenth rib, a large and highly significant difference. There was no difference among the correlations between percent lean cuts and loin area at the tenth and last ribs, although the latter area was slightly more closely related to percent loin. All of these correlations varied from .65 to .74. There was no difference among the correlations as regards whether the traits considered were measured on the same or different sides of the body. Because of the high correlation between loin areas on the same carcass, there is little increase in accuracy of predicting lean cuts from measuring the loin area in more than one place.