Nutritive value index of treated wheat straw with Pleurotus fungi

Wheat straw was inoculated with spawns of two species of Pleurotus fungi (coded: PF and PO) and incubated in a fermentation room at 22?5?C and 70?5, relative humidity. After 17 days of spawning, when the substrate was completely covered by fungal mycelia, half of the bags were removed from the fermentation room, sun dried and used for in vitro measurements and in vivo study as well, using of sheep. For the remainder of the bags, fermentation was allowed for seven weeks during which the fruiting mushroom was harvested two times, and then spent straw was collected and dried under the sun. In a feeding trial, in vivo digestibility and voluntary intake of treated straw was compared with initial straw in cattle, when the dietary treatments were: 1) Initial wheat straw (IWS); 2) Fungal (PF) treated wheat straw before mushroom formation (FTWS); 3) Fungal (PF) spent wheat straw (SPWS) after mushroom was harvested. Results showed that, the fungal treatments significantly (P<0.05) affected the nutrient composition of wheat straw by increasing the CP and ash, but decreasing the OM, NDF, ADF, ADL, cellulose (CL) and hemi cellulose (HCL) contents. The in vitro digestibility of DM and OM were significantly (P<0.05) the highest for PF treated straw but the lowest for the initial straw. The in vivo digestibility of most components were significantly (P<0.05) increased, in sheep, however treatment PF showed the higher amounts of digestibility than that of the PO with exception for crude protein CP and HCL. Regarding the feeding trial by cow, results indicated that, the highest amount of DM and OM digestibility were found in FTWS followed by SPWS, but the initial straw had the lowest digestibility (P<0.05). Average daily intake of DM, OM, as well as the digestible DM and OM intake were significantly (P<0.05) affected by the treatments. In comparison to the IWS, PO inoculated straw increased the voluntary intake of digestible DM and OM, at the stage of mycellial running, however, the digestibility and intake of SPWS were significantly (P<0.05) reduced to the level of initial straw. In conclusion, fermentation of wheat straw by Pleurotus florida and P. ostreatus, improved the nutritive value of straw although the effect of P.F. was more than that of the P.O. In addition, fungal treatment of straw before mushroom formation, improved the nutritive value index, but no enhancement was found in SPWS comparing with the initial straw.