The lambs were fed in four groups. Lambs of control group (WS, n = 6) received untreated WS without supplemental yeast, whereas other three groups were fed WS treated with anhydrous ammonia (WSNH3 group, n = 7), untreated WS and yeast (WS+YEAST group, n = 6) or WS treated with anhydrous ammonia and yeast (WSNH3+YEAST group, n = 7).