The dejections produced by caprines were used, in different physiologic states and submitted to the same alimentary regime, in the four seasons of the year.This study was carried out in 60 L batch digesters at ambient temperature and aimed to evaluate the effect of the season on the anaerobic digestion of caprine manure. The biogas production, volatile solids (VS) reduction, the potential production (m³ of biogas/kg of substrate, manure, total solids (TS) or VS), the removal of total and fecal coliforms and the biogas composition were evaluated. The VS reductions were of 38; 34; 33 and 39% for Summer, Autumn, Winter and Spring, respectively. The biogas production were of 1.06 m³ in Summer, 0.88 m³ in Autumn, 0,88 m³ in Winter and 0.99 m³ in Spring and the mean potential production were of 0.02 m³ of biogas/kg of substrate and 0.2 m³ of biogas/kg of manure for all seasons. The batch digesters reduced total and fecal coliforms densities in 99.99% and the CH4 contents in biogas were 88.3; 84.6; 80.6 and 79.2% for Summer, Autumn, Winter and Spring, respectively.
biogas; goat; dung
