For the pig breeder there are many important selection objectives - optimum progress can be made if sires and dams are selected for different objectives. In dam lines some emphasis on maternal traits is practicable while maintaining slightly higher fat levels than in sire lines. Meanwhile lean growth and low fatness can be emphasised in the terminal sire lines. This gives the flexibility to fulfil different end markets and weights. Selection accuracy in such programmes is often improved by the addition of detailed carcass information from slaughtered sibs or other relatives of selection candidates.

For the commercial producer, classification schemes differentiate payments on the basis of backfat and in some cases, lean measurements. However, despite the fact that future payments are likely to place greater emphasis on leanness, there is no differentiaton for breed or genotype.

The purpose of this investigation was to follow up a previous study (Walters and Simpson, 1988) to determine whether lean prediction in the carcass depends on slaughter weight and genotype, to identify the best predictors of leanness and to estimate multiple correlation coefficients for predicting lean in carcass from lean in sample joints.