Rate and Extent of in sacco Degradation of Dry Matter and Cell Wall Constituents of Various Grass Species

Potential dry matter (DM), cell wall (NDF), acid detergent fibre (ADF)) hemkeilulose and cellulose digestion for the grass species under study averaged 63.3, 57.3, 53.9, 63.2 aan 60 3 %, respectively. Lignin, NDF and ADF content of the forage had d significant effect on the ektent of digestion. Lignin protected DM, NDF, ADF and hemicellulose from microbial attack to an almost similar extent. Lag was not tetected for DM digestion but cell wall and ADF degradation exhibited lag. Lag was not significantly affected by proximate or fibre composition of the forage. The fractional digestlon rates varied from 0.0337 to 0.0884/h for DM; 0.0370 lo 0.0789/h for NDF; 0.0373 to 0.0886/h for ADF and 0.0311 to 0.0732/h for hemkellulase. The average digestion rates for DM (0.0445/h), NDF (0.0450/h), AAD (0.0468/h) and hemkellulose (0.0427/h) indicated that these were degraded at almost similar rates in the rumen. Fibre composition significantly affected the rate of digestion. The amount of potentially digestible DM, CWand ADF digested at various digestion end point varied from forage to forage. Rumen fill was primarily controlled by the rate and extent of digestion. Based on the digestion kinetlc parameters, it may be concluded that among the forages tested, oats was superior; para, rhodes, maize, kikuyu and guinea were medium ana setaria cultivars were poor forages for ruminants in terms of intake and energy yielding potential.