Effect of Stilbestrol and Pelleting at Two Concentrate to Roughage Ratios on the Performance and Carcass Quality of Fattening Lambs

Abstract

In a factorially designed experiment 698 Texas old-crop feeder lambs were allotted to eight treatments consisting of two rations, low roughage (29% alfalfa hay) and high roughage (59% alfalfa hay) either pelleted or non-pelleted, with and without stilbestrol (0.5 mg. per lb. of feed). No appreciable differences in rate of gain were observed between the two rations. Lambs receiving the low roughage ration had a 12% improvement in feed efficiency, an 0.86% lower shrink from the feedlot to market, and a 1.15% higher yield. Pelleting the low roughage ration gave no advantage in liveweight gain or feed efficiency; it increased the number of oily carcasses. Pelleting the high roughage ration increased gain and feed consumption, but not feed efficiency, over the meal form. Stilbestrol significantly (P<0.05) improved both gain and feed efficiency by 14%; however, it reduced dressing percentage by 0.49 and increased the number of carcasses with yearling break joints. The grades of the lambs were similar for all treatments. Copyright © . .