Gas volume is a good parameter for predicting digestibility, VFA production, and microbial protein synthesis. As documented in previous research, IVRDMD has a high correlation with gas production (13). Enhanced IVRDMD may be due to the release of reducing sugars with direct application of enzymes to the substrate (14), partial solubility of neutral detergent fiber and acid detergent fiber (15), and better absorption of the enzyme during preincubation as it is an important prerequisite for hydrolysis (16). Forsberg et al. (16) demonstrated that release of soluble sugars would provide sufficient additional available carbohydrates to encourage rapid microbial growth, shortening the lag-time required for microbial colonization and suggesting that exogenous enzymes caused structural changes to forages that improved digestion. Yang et al. (5) and Bhasker et al. (17) confirmed these results, showing increased IVRDMD in cereal straw supplemented with cellulase enzyme and a mixture of the enzymes cellulase, hemicellulase, protease, and amylase