Abstract
Wheat straw was treated with 3.2, 4.3 and 5.3 g of urea and 58.5 ml of water 100 g-1 straw DM and ensiled for one month at 26 ± 2°C ambient temperature. The treatment did not change the cell wall constituents of the straw, but the N content and nylon bag DM degradability (NBDMD) at 48 h increased significantly (P < 0.01); the increase was similar irrespective of urea levels. In another experiment, treatment with 3.2% urea for 1, 1.5, 2, 3 and 9 months with 0, 8.0, 16.8, 25.3, 33.7 and 42.1 ml of water 100 g-1 DM of wheat straw gave maximum NBDMD at 40 - 50 ml of water and treatment duration of one month. In extended durations NBDMD decreased. Water alone decreased (P < 0.01) NBDMD and maximum degradability was observed at 70 ml water along with 3.2 q urea 100 g-1 straw DM in another experiment. However, water level could be reduced to 33.5 ml 100 g-1 DM without decreasing degradability significantly. A feeding trial with nine buffaloes showed that 3.2 kg urea 100 kg-1 straw DM along with 58.5 I of water, and one month treatment resulted in 19% increase in DM digestibility. Urea solution added at the time of feeding did not have a similar effect. Total digestible nutrient requirements of buffaloes could be met with treated straw, as DM intake was also increased by 48%. However, the animals showed negative N balance; about 64% of increased N intake passed out in faeces.
