Exogenous feed enzymes that contain

Exogenous feed enzymes that contain fibrolytic activities
may help enhance fiber digestion in the rumen
(Feng et al., 1996; Yang et al., 1999; Kung et al., 2000),
which could lead to improved feed conversion efficiency.
Improvements in ruminal fiber digestibility of feed
would also allow dairy producers to feed higher forage
diets or high-fiber byproduct feeds without compromising
energy intake or animal productivity.
Fibrolytic enzyme additives of interest for ruminants
are concentrated fermentation products containing a
broad spectrum of carbohydrases, including cellulases
and hemicellulases. However, most commercial enzyme
products containing cellulases and xylanases have been
designed for use in the food, textile, or chemical industries
(Bhat and Hazlewood, 2001). Enzyme activities
provided by the manufacturers for these products have