Note: where digesters A, B and C were loaded with 225 g of poultry waste and 75 g of cow dung (ratio 3:1) mixed with 150 mL of water, Digester B loaded with 150 g of poultry wastes and 150 g of cow dung, mixed with 150 mL of water and Digester C was loaded with 75 g of poultry wastes and 225 g of cow
dung mixed with 150 mL of water.