Viabilidade de ovos de Fasciola hepatica de bovinos em sistema de biodigestão anaeróbia Viability of bovine's Fasciola hepatica eggs in a system of anaerobic biodigestion

<abstract language="eng">Cattle Fasciola hepatica egg-viability was studied in closed system of anaerobic biodigestion. Two thirds of a biodigestor were filled with liquefied manure from eight Hosltein cows, naturally infected. For 10 consecutive weeks of observation, the biodigestor internal temperature ranged from 24ºC to 28ºC, and external temperature from 26ºC to 33ºC. All the effluent samples showed a constant pH of 7. The samples of the effluent were weekly collected, in a total of 10 and submitted to techniques to detect the presence and viability of the trematode eggs. It was detected a 42-day egg viability. Therefore, liquefied cattle manure containing Fasciola hepatica eggs must remain under anaerobic biodigestion for at least 42 days before its safe return to the environment