Production of methane gas from animal manure has received increasing attention throughout the world as efforts to find alternate energy source intensify. Some of the kinetics of the anaerobic digestion under laboratory condition were investigated using feces of dairy cows.
    The results obtained were as follows :
1. When a continuous anaerobic digestion was carried out at loading rate of 3.06 kg volatile solid (VS) per day, steady-state periods were shown after about 21 days of operation.
2. In batch-loaded operation, adding rice straw at a concentration of 0-6 % to the diluted feces resulted in the same response. However, at more than 10% of rice straw, the amount of gas produced was significantly lower.
3. Diluted sample can be regarded as pseudoplastic fluid when moisture content is less than 2,400% (d.b.), while diluted one having moisture content more than 3,000% (d.b.) is Newtonian.
4. When a temperature of the sample solution was lower than 30 centigrade, the viscosity increased with an decrease in the temperature. The solution ranging from 30 to 55 centigarde had the lowest viscosity. As the solution became acid or alkaline, the viscosity went up. However, the solution with a pH of 7-8 had the lowest viscosity.