Effects of exogenous fibrolytic enzymes on in vitro ruminal fermentation of substrates with different forage:concentrate ratios

Batch cultures of mixed rumen micro-organisms were used to study the effects of three fibrolytic enzymes (xylanase from Trichoderma viride (XYL) and fibrolytic enzymes from Aspergillus niger (ASP) and Trichoderma longibrachiatum (TR)) on the fermentation of three substrates composed of grass hay:concentrate in the proportions (dry matter (DM) basis) of 0.7:0.3 (HF), 0.5:0.5 (MF) and 0.3:0.7 (LF). Enzymes were characterized for xylanase, endoglucanase, exoglucanase and amylase activities, and were supplied at rates of 40 and 80 enzymatic units/g substrate DM. In 8 h incubations, all enzymes increased (P=0.048 to P