Effects of mushroom stump waste inclusions to broiler diets on amino acid digestibility and d1–21 performance

Mushroom cultivation in the United States generates a considerable waste stream of inutile mushroom stumps. Stumps were dried and ground to create the current study's mushroom stump waste (MSW) product. This study aimed to determine the energy and amino acid profile of MSW and the optimal inclusion of MSW in broiler diets based on performance measurables and amino acid digestibility. The TME_n of MSW (1,173 kcal/kg) and proximate analysis results were used to formulate broiler diets containing 0% and 5% MSW which were blended to create experimental diets containing 1, 2, 3, and 4% MSW. Day 21 performance results indicate birds consuming 1% MSW improved LWG by 57.6 g per bird compared to birds fed 5% MSW. Birds fed 0, 2, 3 or 4% MSW were intermediate for LWG (P = 0.024). Broilers provided 1% MSW improved average body weight (BW) compared to those fed 4 or 5% MSW. Birds consuming 0, 2, or 3% were intermediate for BW (P = 0.026). Birds fed 1% MSW improved FCR by 0.105 compared to those fed 5% MSW. Broilers consuming 0, 2, 3 or 4% MSW were intermediate for FCR (P = 0.0002). Neither mortality nor feed intake were affected by MSW inclusion (P > 0.05). Although 16 of the 19 reported AA had reduced AIAAD when MSW was included (P < 0.05), amino acid digestibility coefficients were not affected by MSW inclusion (P > 0.05). These data support MSW inclusion in broiler diets up to 3% without detriment to performance or amino acid digestibility coefficients.