Degradabilidade in situ da matéria seca e da fração fibrosa do bagaço de cana-de-açúcar tratado com uréia

The experiment was conducted to evaluate the in situ degradability of dry matter (iDMD), neutral detergent fiber (iNDFD), acid detergent fiber (iADFD) and hemicel-lulosis of sugar cane bagasse submitted to ammoniation with urea. The treatments consisted of four urea levels (0%, 2.5%, 5.0% and 7.5% on dry matter – DM basis) added to the sugar cane bagasse and addition of 1.2% (DM basis) of ground soybean as urease source. Samples of 3 g of the bagasses were incubated in the rumen of three steers during periods of 0, 12, 24, 48, 72 and 96 hours. The urea addiction to sugar cane bagasse provided increase not only on the iDMD, but also in degradability of cell wall con-tents. The degradability increased of 73.6, 61.3, 45.6 and 65.7% for DM, NDF, ADF and hemicellulosis, respective-ly, at the longer incubation time (96 hours). The iDMD, iNDFD, iADFD and in situ hemicellusosis degradability of sugar cane bagasse were improved by urea treatment. KEY-WORDS: Ammoniation, by product, dry matter, cellular wall.