The effect of fibrolytic enzymes addition (cellulase and xylanase) on the DM, CP, NDF, ADF, and hemicellulose in situ degradability of Tifton 85 hay (Cynodon spp.) cut at 30 and 90 days and sugarcane bagasse were evaluated with six bovines cannulated on the rumen. The enzymes were extracted from Aspergillus niger and Trichoderma longibrachiatum fungi and supplied 0.75 g/kg of DM/animal.day, through ruminal cannula. The incubation times were 0, 3, 6, 12, 24, 48, 72, and 96 hours. The incubation residues were compared by scanning electron micrographs (SEM). The effect of enzyme addition on the DM and CP degradation varied in function of roughage studied. The effective degradability of DM of Tifton 85 hay cut at 30 and 90 days and sugarcane bagasse, without enzymes addition, was 61.85, 42.35, and 28.22%, respectively, and 63.51, 40.64, and 31.43%, respectively, with enzymes addition. There was no effect of enzymes on the fiber degradation. The SEM observations showed that bacterial colonization increased on the cell wall of roughages with enzymatic supplementation. The fibrolytic enzyme addition to the ruminant diet presented little expressive effect on the degradation parameters of studied roughages.
cellulase; fiber; microrganisms
