The aim of this survey was to evaluate the possible alterations that exist in composition and in anaerobic biodigestion process of cattle manure in phase of slaughter and fed with different proportions of roughage: concentrate and with different times of hydraulic retention (THR). 24 batch digesters of bench with capacity of 12 liters, from which 12 were provided with cattle manure that were fed with diet 1 (60% roughage: 40% concentrate) and diet 2 (40% roughage:60% concentrate) and submitted to 30; 60; 90 and 120 days of TRH were used. The efficiency of anaerobic biodigestion process was evaluated by reductions of total solids, volatile solids; neutral detergent fiber, acid detergent fiber, cellulose and the most probable number (MPN) of total and thermo tolerant coliforms, and production potential of biogas and methane were evaluated. Results showed that the increase of roughage proportion in diet conduced the smallest efficiency in the process, mainly in the production potential of biogas and methane, which were, in average, 13% smaller. Regarding to MPN of total and thermo tolerant coliforms, significative reductions as increased THR were observed.
diets; biodigestor; energy; methane
