The Effect of Urea Block Supplementation on the Utilisation of Roughage by Sheep

Blocks containing urea were provided to groups of penned sheep fed ad libitum on roughage of either 2.3 % or 5.1 % crude protein content and the results were compared with unsupplemented groups. One block contained 7.1% urea with finely ground sorghum, distillers solubles, common salt and rock phosphate. The other block contained 30.070 urea with common salt, rock phosphate, molasses and pollard. When the low protein roughage was fed, the low urea block, at the end of 103 days, had significantly increased survival rate and clean fleece weight, and decreased body weight loss. Roughage intake was increased by 2.6 times. The high urea block significantly increased survival rate but did not affect body weight loss nor clean fleece production. When the medium protein roughage was fed, the low urea block, at the end of 75 days, had significantly increased body weight gain and clean fleece production but roughage intake was not significantly different from the unsupplemented group. No significant differences were observed when the high urea block was fed with this roughage.