The effects of temperature on biogas production and the heating strategy for anaerobic digestion of swine wastewater were investigated. Through a kinetic model, the maximum volumetric rate of biogas production (R-pmax) for digestion at 15, 20, 25, 30, and 35 degrees C were found to be 0.282, 1.189, 1.464, 1.789, and 2.049 L L-1 d(-1), respectively. The temperature-activity coefficient of R-pmax was 1.332 at 15-20 degrees C, 1.043 at 20-25 degrees C, 1.041 at 25-30 degrees C, and 1.028 at 30-35 degrees C. Anaerobic digestion appeared to be more sensitive to temperature variation within 15-20 degrees C than to variation within 20-35 degrees C. In terms of energy input-output ratio and total annual cost, the optimal heating strategy is an increase in the fermentation temperature from 15 to 20 degrees C. (C) 2014 Elsevier Ltd. All rights reserved.