Evaluation of the Magnitude of Ractopamine Treatment Biases When Fat-Free Lean Mass is Predicted by Commonly Used Equations

Purdue Universtiy 2003 Swine Reserach Report. Numerous research trials have been conducted which have evaluated the impact of ractopamine (RAC) to alter carcass composition. In most trials, the carcass composition of pigs fed RAC was predicted using equations developed from pigs not fed RAC. Substantial biases have been found in the prediction of the fat-free lean mass of pigs fed RAC (Gu et al., 1992). The objective of this study was the evaluation of the effect of RAC, dietary lysine, and crude protein (CP) on the prediction of carcass fat-free lean mass using alternative prediction equations.