This research was conducted with the aim of using Gompertz kinetic model to predict biogas production. The substrates used are the co-digestion of pig and poultry dungs. Batch culture of anaerobic digestion was used while MgSO4, Bovine blood, Charcoal water and water of pH 8 were used as various treatments. Three batches of digestions were done. From the results and statistical kinetic modelling, magnesium sulphate which serve as source of water hardness proved to enhance biogas production. This is because it serves as both salt and catalyst. Bovine blood also showed the same effect. For the charcoal water, it enhanced methane production by the increase of carbon level in C:N ratio. The research recommends as follows. That the quantity of the substrates should be enough to ensure more gas yield. The volume of blood should not be more than the water used in the slurry formation as this could affect proper mixing. The carbon content of the lignocellulose should be increased using charcoal water in slurry preparation to ensure formation of Methane (CH4) which is the main biogas. And finally that measured amount of bovine blood, Magnesium Sulphate and Charcoal can be used as additive in biogas production.