Ractopamine Treatment Biases in the Prediction of Fat-free Lean Mass

Purdue University 2002 Swine Research Report. Numerous research trials have been conducted which have evaluated the impact of ractopamine (RAC) to alter carcass composition. In the majority of these trials, carcass composition of the control and RAC fed pigs was predicted from equations including standard carcass measurements. Substantial biases have been found in the prediction of the fat-free lean mass of pigs fed RAC (Gu et al., 1992). The objectives of this study were 1) to evaluate the effect of RAC and dietary lysine and crude protein (CP) on the prediction of alternative carcass composition endpoints; and 2) to evaluate the ability of prediction equations that include partial carcass dissection or chemical analyses to minimize prediction biases.