It was evaluated the effect of a fybrolitic enzyme product (cellulases and xylanases) on in situ digestibility of dry matter (DisMS), residual neutral detergent fiber (DFDNr) and acid detergent fiber (DFDAr), in dehydrated ground prickly pear diets with a low or high level. Enzyme concentrations of 0, 1, 2, and 3 g kg-1 of dry matter applied at the beginning (0 hour) and 24 hours before starting in situ digestibility were used. Total volatile fatty acids and ammonia nitrogen were determined at: 0, 3, 6, 9, 12, and 24 hours after the enzyme application. There were no effects on DisMS, DFDNr, and DFDAr. Initial application of enzyme concentrations (0 hour) was higher than 24 hours for DisMS and DFDNr but lower for DFDAr. No differences were observed in interactions among enzyme level, diet and application time. Application of 1 and 3 g of the enzyme to the diet with the low level of prickly pear forage had effects on the increasing of volatile fatty acids; for ammonia nitrogen, the best results were obtained using 0 and 1 g of the enzyme.
Opuntia ficus-indica; cattle; cellulases; xylanases; volatile fatty acids; ammonia nitrogen
