Livestock production residues are commonly used as substrates in agricultural biogas plants for energy recovery. Cattle and poultry manure can be converted to biogas in farm-scale or centralized biogas plants to produce heat and power. This study investigated batch anaerobic digestion of chicken manure coupled with a biological pre-treatment step. The primary objective of this laboratory-scale work was to improve the biological degradability of the mono substrate to obtain higher biogas and methane yields through using an enzymatic pre-treatment. The experimental results showed that the enzymatic pre-treatment for the chicken manure significantly increased the biogas production by about 35% in comparison to the control without enzymatic pre-treatment. Therefore, it can be concluded that the enzymatic pre-treatment of chicken manure could provide improved biogas and methane yields when the chicken manure is used as mono substrate for anaerobic digestion in agricultural biogas plants.