The utilization of urea-supplemented and ammoniated barley straw in sheep.
Barley straw treated with urea (75 kg/ton straw) and with anhydrous ammonia (30 kg/ton straw) by the stack and oven methods were compared with urea-supplemented barley straw in an intake and in vivo digestibility study. The ADF-N content of the barley straw was increased by 73 – 107% by ammoniation. Ammoniation improved the dry matter (DM) and organic matter digestibility of the barley straw (P ≤ 0,05), possibly as a result of the higher fibre digestibility. The DM and organic matter digestibility of the urea-ammoniated straw was correspondingly significantly (P ≤ 0,05) higher than that of the anhydrous ammoniated straw. The crude protein (CP) digestibility of the urea-ammoniated straw was higher than that of the anhydrous ammoniated straw treated according to the stack and oven methods. The voluntary intake on the oven-ammoniated straw was 34% higher than that of the urea- and anhydrous-ammoniated (stack-method) straw which were similar to each other. The latter treatments tended to have a higher voluntary intake than the urea-supplemented control (P = 0,1).