Anaerobic biodegradability of Category 2 animal by-products: Methane potential and inoculum source

► Methane production from animal by-products is affected by the inoculum source. ► Landfill leachate and sludge from anaerobic lagooning are good inoculum sources. ► The maximum methane production rate is 35 mL CH4 g−1 VSsubstrate d−1. ► The biodegradability of Category 2 animal by-products is inhibited at 5% TS.