Pleurotus ostreatus EFFECTS ON AGRICULTURAL WASTE DEGRADATION.

Abstract

Insufficient food amount for ruminants in tropical areas is due to limited availability of pastures at critical times (excessive rains or droughts) and agricultural waste is an alternative for those alimentary shortages. The objective in this study was to determine the effect of the fungus Pleurotus ostreatus on fiber degradation from agricultural waste. Our hypothesis was that inoculated P. ostreatus increases fiber degradation. Pleurotus ostreatus was cultivated in corn (Zea mays), beans (Phaseolus vulgaris) and sugar cane (Saccharum officinarum) residues for 30, 45 and 60 d, in a completely randomized experimental design with a 3´3 factorial arrangement. The factors were substrates (corn, beans and sugar cane) and fungus growth time (30, 45 and 60 d). A non-linear fit with the Orskov and McDonald model was made to describe ruminal kinetics of effective degradation. The evaluated variables were: dry matter (DM), crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF) and the effective DM, NDF and ADF degradation. The substrates generated significant differences in the growth in DM, NDF and ADF; the CP showed differences in the substrate factor and the effective degradability was significant on the substrates and growth days with DM, NDF and ADF. Pleurotus ostreatus improved the quality of the agricultural residues evaluated through ADF degradation.