Effect of a Combination of Diethylstilbestrol and Methyltestosterone and Protein Level in the Diet on Performance and Carcass Traits in an Unselected Line of Swine

Abstract

Summary TWO experiments involving 372 barrows were conducted to evaluate the effects of orally administered diethylstilbestrol (DES) and methyltestosterone (MT) with varying levels of dietary protein.The DES-~-MT combinat/on significantly increased carcass leanness regardless of dietary protein level. No significant effects of dietary protein levels on carcass leanness were observed with the barrows used in this study. It appears carcass leanness was maximized at the dietary protein level of 12%.Daily gains were significantly reduced by DES-{-MT over all dietary protein levels. However, the amount of depression was reduced by adding the hormone to the diets at a heavier weight. Significant interactions were present between dietary protein levels and DES+MT on daily gain. Greater depression of gain occurred on the lower dietary protein levels when DES+MT was added to the diet.The effect of D,ES+MT on feed efficiency was inconsistent between experiments. A small significant effect of dietary protein level ori feed efficiency occurred in experiment 1. Feed efficiency appeared to be maximized at the 12% level in this study.