Rajagopal et al. [ 62] investigated chicken manure fermentation (with straw) at a TS concentration of 30%. Anaerobic digestion with a loading rate of 5.4 g VS/ (kg inoculum*day) and 21.6 g VS/ (kg inoculum*day) at 20 °C was conducted. The authors reported that methane yield was lower at a higher loading rate.