[Survival of parasitic elements in liquid manure: effect of xylene (author's transl)]

The spreading of liquid manure may play a role in the transmission of parasitism. In this preliminary study, we have investigated the evolutionary and survival capacities of parasitic elements in liquid manure, their development potential after extraction and the destructive action of xylene in concentration of 1 p. 1000. As parasitic models we have retained: the coccidial oocyst (E. tennella), a thick-shelled egg (A. suum), thin-shelled eggs (H. contortus, O. quadrispinulatum), a trematode egg (F. hepatica) and larva III of H. contortus. The studies were carried out in Erlenmeyer with parasite free liquid manure taken from a bovine cowshed. Water was used as control medium. The parasitic models were kept in the liquid manure for a maximum of 17 days excpet for Ascaris suum, 45 days. Only the coccidial oocyst is little affected. The eggs of Trichostrongylides and of Fasciola show a poor resistance to this environment and to a lesser degree the egg of Ascaris. The larvas III are rapidly destroyed and those obtained from eggs that stayed in liquid manure have a greatly diminished viability. The antiparasitic action of xylene varies according to the type of parasitic element. Its action is particularly clear on the eggs of Trichostrongylides and of Fasciola hepatica.