SUMMARY

This study was conducted to determine the effect of Zeranol and the yeast culture Saccharomyces cerevisiae (SC) on performance and carcass traits of finishing lambs. Sixty-four wether lambs (average initial weight of 39.1 kg) were selected and pair-fed diets (12% crude protein; CP) based on 85% high-moisture corn and 10% corn silage. Treatments were arranged as a 2-by-4 factorial with lambs either implanted (IM) or non-implanted (NI) and supplemented with SC at 0, 0.5, 1.0 or 1.5 g/head/day. Lamb average daily gain (ADG), feed efficiency and feed intake (FI) were not affected (P > 0.05) by dietary level of SC. Implanted lambs had a higher (P < 0.05) ADG and a more efficient (P < 0.05) feed conversion than NI lambs. There were no differences (P > 0.05) in Fl regardless of lamb implant status. Total carcass lean deposition and hot carcass weight were greater (P < 0.05) in IM lambs compared to NI lambs. The level of SC fed had no (P > 0.05) significant effect on lamb carcass composition. These results indicate that lambs implanted with Zeranol grew faster, were more efficient in feed utilization and had heavier carcasses with increased carcass lean and fat deposition.

Sheep & Goat Research Journal, Vol. 13, No. 1: 1997