Urea-salt block supplementation of adult Merino wethers grazing wheat stubble in Western South Australia

Abstract

Blocks containing 30 and 35 per cent urea were offered to adult Merino wethers grazing wheat stubble during summer and autumn of 1965. Two groups of sheep were supplemented with two different urea-salt blocks while a third group had no supplement. Urea consumption from the two blocks was 5.3 and 7.2 g per sheep per day. Supplemented sheep had a significantly higher (P<0.05) apparent herbage consumption, but showed less selectivity in grazing for a high protein diet. Supplemented sheep had significantly higher (Pt0.05) liveweights, but four months after the experimental period there were no significant liveweight differences. Supplementation had no effect on wool production. Although the sheep had ad libitum access to the blocks no cases of urea toxicity were reported.