Nutritional evaluation of Pleurotus florida harvested spent wheat–rice straw based diets in goats

Abstract

An experiment was conducted to evaluate the nutritional worth of spent wheat straw-rice straw (WS-RS) in 50: 50 ratio in the complete feed of goat kids. The cultivation of Pleurotus florida (edible mushroom) on WS-RS (50: 50) resulted in low in OM, hemicellulose and NDF but enriched the straw with microbial protein. The digestion kinetic parameters for DM and NDF revealed that insoluble but potentially degradable fraction was low in spent WS-RS as compared to ordinary WS-RS. The apparent extent of digestion was lower in spent WS-RS as compared to WS-RS, resulting in higher rumen fill value predicting low voluntary DM intake in spent WS-RS. The loss in OM and other nutrients during fungal cultivation resulted in low net gas production and low in-vitro OM and NDF digestibility in spent WS-RS. The in-sacco and in-vitro gas production studies revealed that the spent straw due to heavy OM loss during mushroom cultivation had lower nutritional worth as compared to WS-RS. The effect of incorporation of WSRS or spent WS-RS in isocaloric and isonitrogenous complete feed on the performance of goat kids was assessed. The WS-RS or spent WS-RS along with concentrate in 60: 40 ratio for 90 days revealed that spent WS-RS diet was palatable as indicated by higher DM intake. The digestibility of nutrients (except that of cellulose which was depressed), blood profile (except total protein and globulin which were depressed), N-retention, apparent biological value and daily live weight gain were comparable in both the groups. It was concluded that though spent WS-RS had lower nutritional worth than WS-RS but could be incorporated in isonitrogenous and isocaloric complete feed without any adverse effect on the performance of kids.