The objectives of this research were to produce and characterize an enzyme complex (EC), using the fungus Humicola grisea , and evaluate its effect on true digestibility of forage maize dry matter. We observed that the fungus produced cellulase, b-glucosidase and xylanase enzymes. The cellulase and xylanase activities were high at the temperature of 50° C. The optimum temperature of ?-glucosidase was between 50 and 60° C. The optimum pH of cellulase and xylanase enzyme was 6.0. As for ?-glucosidase, the enzyme showed higher activity at pH 6.5. Cellulase remained stable for 60 minutes at 39° C. Xylanase and ?-glucosidase maintained 99.2 and 88.2% of their activity at 50° C for 240 minutes, respectively. The treatments were as follows: control (10 mL of sterile water), level 1 (2.5 mL EC), level 2 (5.0 mL EC) and level 3 (10 mL EC). In the digestibility experiment, there was interaction between enzyme levels and time of incubation in the rumen. The addition of 10 mL of the fibrolytic enzymes improved the digestibility at 10.58; 12.52; 9.05 and 6.81% compared to control for 12; 24; 48 and 96 hours of incubation, respectively. The fungus Humicola grisea is an enzyme producer that is important in ruminant feed. KEYWORDS: Ankom; bovine; cellulose; fungi; xylanase.