Effect of anaerobic enzyme matrix on fiber digestibility

Abstract

The intend of this study was to verify the effect of nutritive value aerobic constancy of rice straw. Also, if it could be enhanced by addition of exogenous cellulases, hemicellulase, protease and α amylase enzymes (ZAD) preparations at ensiling. Rice straw was chopped to 5 cm without treatment (control) or after treatment with ZAD (1 or 3 L/ 1 ton of DM of rice straw) including 30 kg of sugar cane molasses and 20 kg of DDGS. The enzymes were sprayed on the rice straw at ensiling (50% of water was added). Ten 500-kg replicates of chopped (5 cm) rice straw were ensiled for 30 d in plastic bales. Five plastic bales per treatment were used for chemical analysis and 5 for aerobic constancy monitoring. The silage juice was analyzed for organic acids, pH, water-soluble carbohydrates (WSC), ammonia-N, and soluble N. Samples were analyzed for crude protein (CP), neutral detergent fiber (NDF), and acid detergent fiber (ADF). In vitro digestibility of DM (IVDMD), NDF (IVNDFD), and ADF (IVADFD) were determined. Materials treated with ZAD had lower (P < 0.05) DM losses, and lower (P < 0.05) pH and ammonia-N concentration than control silages. Residual WSC concentration was greater (P < 0.01) in ZAD treated silages either 1 or 3 L than in control silages. Compared with control silages, NDF concentration was lower (P < 0.01) in silages treated with 3 L followed 1 L of ZAD. Aerobic constancy was increased (P < 0.05) by ZAD. ZAD at 3L increased the IVDMD and IVNDFD at 6 and 48 h. The 48-h IVADFD was also increased (P < 0.01) by treatment with 3L ZAD. These results show that 3L ZAD applied at ensiling can improve the digestibility, fermentation, and aerobic constancy of rice straw silage.