Effect of continued culture of spent corncob meal medium with Pleurotus eryngii on the nutrition value of the medium

3481 Pleurotus eryngii was cultured on corncob meal medium for 175 days after inoculation, and changes in digestibility and fibrous composition of the medium were examined. The culture medium consisting of corncob meal, rice bran and Ca(OH)2 was incubated at 24 deg C for 45 days after the inoculation of sawdust spawn under semi-anaerobic conditions and was transferred to an incubation room of 17 deg C to enable the fruit-bodies to emerge. Three bottles each were sampled before inoculation (0), and on days 45, 75 (first flush), 95, 115, 135, 155 and 175 after inoculation. Fruit-body yield, medium of the neutral detergent fiber (NDF), acid detergent fiber (ADF) and acid detergent lignin (ADL) contents, and in vitro organic matter digestibility (IVOMD), neutral detergent fiber digestibility (IVNDFD) and gas production (IVGP) were determined. The average yield of fruit-bodies at the first flush was 117.6g/culture bottle. The weight of dry matter in the medium decreased 31.3% at day 1l5 and further decreased 6.8% between days 115 and 175. The weight of hemicellulose decreased 71 .5% at day 115, and decreased a further 7.5% between days 115 and 175. The weight of ADL decreased 49.5% at day 115, and decreased a further 22.8% between days 115 and 175. Meanwhile, the weight loss of cellulose was smaller than that of hemicellulose and ADL, and was 1 7.7% at day 115, and decreased a further 7.2% between days 115 and 175. The IVOMD in the medium increased from 73.6% at day 0 to 91 .0% at day 115, and to 94.0% at day 175. The IVNDFD increased from 69.3% at day 0 to 87.1% at day 115, and to 90.8% at day 175. The cumulative IVGP for 48 hr increased from 230 ml/g OM at day 0 to 258ml/g OM at day 115, and to 266ml/g OM at day 175. Since there were no significant differences in IVOMD, IVNDFD and IVGP at 115 and 175 days, it was concluded that an appropriate culture length was more than 115 days after inoculation and we believe that spent corncob meal medium could be used as feed under the conditions used in the present study.