Four Holstein Friesian crossbred cows, with an average initial weight of 460 kg, were used in a 4x4
Latin square design with a 2x2 factorial arrangement. 28-d period to investigate the effects of supplementation level
of fibrolytic enzyme (50 mg/kg DM) on rumen fermentation and digestibility in cows fed straw-based total mixed
ration (TMR) or fermented total mixed ration (FTMR). The results found that DMI did not affected by fibrolytic
enzyme supplementation. However, fibrolytic enzyme supplementation did improve rumen pH and digestibility
of nutrients in TMR, but did not observe in FTRM. Under this study, supplementation of fibrolytic enzyme could
enhance feed utilization in dairy cows.