SUMMARY

Forty-eight wether lambs were fed pelleted, grain-based diets differing in source and level of crude protein (CP). Diets contained either soybean meal (SBM) or SBM plus fishmeal (SBM + FM) at levels of either 13% or 16% CP on a dry matter basis. Lamb average daily gain (ADG), feed intake (FI), feed to gain ratio (F:G), total carcass lean, percent carcass lean, leg lean, yield grade (YG) and ribeye area (REA) were used to evaluate treatment effects. Source of dietary CP had no effect on any of the response variables. Level of CP fed did not influence ADG, Fl or F:G. Lambs fed 16% CP diets tended to have carcasses with increased total lean (P = 0.14), increased percent lean (P = 0.07) and a more desirable YG (P = 0.19) than lambs fed 13% CP diets. Because the source and level of dietary CP had only small effects on lamb performance or carcass traits, producers should use economic considerations when choosing ingredients for finishing lamb diets.

Sheep & Goat Research Journal, Vol. 11, No. 3: 1995