THE KING TUBER MUSHROOM (Pleurotus tuber-regium) ASSISTED FERMENTATION OF RICE HULL COULD BE USED TO PRODUCE RUMINANT FEEDSTUFF IN THE PASTORALIST CONFLICT PRONE SOUTHERN NIGERIA

Abstract

The objective of the study was to improve the nutrient values of locally available rice hull biomass wastes (BWs) by subjecting them to solid-state fermentation using the king tuber mushroom, Pleurotus tuber-regium (PTR). The RHL was composted for seven days and thereafter inoculated with the mushroom spores and fermented anaerobically to achieve mycelia colonization during 20, 30, and 40 days in triplicates in a completely randomized design (CRD). At the end of each period, the RHL was sun-dried, and subjected to physicochemical analysis to determine the effects of the SSF on the RHL nutrient values. The P. tuber-regium was able to colonise the RHL by the 20th day with formation of pin heads which dried by the 40th day. There was significant decrease (p<0.05) crude protein, crude fiber, ether extract and gross energy values of the RHL from control values across fermentation periods. The 40th day nitrogen free extract and ash values however increased by 90.39 and 6.69% respectively over the control values. There were also significant decreases in the 20th day fiber fraction values (p<0.05) over the control value by a range of 7.34% (neutral detergent fiber) to 20.74% (hemicellulose). There was also a significant nutrient improvement (p<0.05) in the total digestible nutrient (TDN) and the TDN:CP ratio values over the control value (39.11 to 42.70% and 3.45 to 4.27%) at the 20th day of fermentation. Based on the

TDN: CP results, the 20th day fermented RHL could be used as protein and energy feedstuff for meat type ruminants with limited energy supplementation. PTR assisted SSF could therefore serve as an innovative method of converting RHL into functional feedstuff for sedentary ruminant production.