Chemical composition and in vitro digestibility of rice straw treated with Pleurotus florida

The purpose of this study was to determine the potentiality of the composting process and biological pretreatment of using P. florida to improve the nutritive value and enhance the digestibility of rice straw. A total of 40 rice straw samples with and without composting treated with P. florida at different substrate harvesting periods (full ramification, 1st, 2nd, and 3rd flushing) were evaluated by analyzing its chemical composition, in vitro digestibility, and scanning electron microscopy (SEM). Results showed that composted and uncomposted rice straw in the 2nd flush had the highest dry matter (DM) content of 96.07% and 95.56%, respectively. The highest crude protein (CP) content (10.57%) was obtained in composted rice straw in the 3rd flush. The composted rice straw treated with P. florida had low organic matter (OM) content but high concentrations of ash, cellulose, and nutrient digestibility. These results indicate that the composted rice straw in the 3rd flush was found to be the best in terms of sufficient degrading of lignin content, minimum loss in cellulose concentrations, enhanced crude protein content, and nutrient digestibility. Therefore, it is recommended to develop spent mushroom substrate feed supplements for possible use in ruminants.