Variations in the survival of Fasciola gigantica eggs in bovine dung stored in the sun as opposed to the shade

摘要

Eggs of F. gigantica were placed in dung heaps that were located in the shade or exposed to sun light, and examined at intervals for up to 14 weeks. The rate and extent of decline in viability of eggs was greater in dung exposed to sun light than in shaded dung. This difference was attributed the higher temperature in dung in sun light, owing to the effect of direct sunlight and to a higher rate of fermentation in exposed than in shaded dung. It was concluded that strategies for storing dung that would reduce the risk it poses for infecting L. rubiginosa with F. gigantica when used as fertilizer in rice fields include storing dung in sun light rather than in the shade, preferably in a thin layer to allow sunlight to heat and desiccate it, and mixing a carbohydrate with the stored dung to increase heat through fermentation.