All waste materials fed to a biogas plant consist of solid substance, volatile organic matter and nonvolatile matter (fixed solids) and water. During anaerobic fermentation process, volatile solids undergo digestion and non-volatile solids remain unaffected (Almukhtar et al. 2012). For optimum gas yield through anaerobic fermentation, normally, 8-10 % TS in feed is required (Rai 2004). This is achieved by making slurry of fresh cattle dung in water in the ratio of 1:1. However, if the dung is in dry form, the quantity of water has to be increased accordingly to keep the desired amount and consistency of the input (i.e., ratio could vary from 1:1.25 to even 1:2) (Rai 2004). If the dung is too diluted, the solid particles will settle down into the digester and if it is too thick, the particles impede the flow of the gas formed at the lower part of the digester. In both cases, gas production will be less than optimum (Anonymous 1987).