RECEPTIVITY AND SUSCEPTIBILITY OF THE DOMESTIC DUCK (ANAS-PLATYRHYNCHOS), THE MUSCOVY DUCK (CAIRINA-MOSCHATA), AND THEIR HYBRID, THE MULE DUCK, TO AN EXPERIMENTAL-INFECTION BY EIMERIA-MULARDI

The receptivity and susceptibility of the Muscovy duck, the domestic d uck, and their hybrid, the mule duck, toward an experimental infection by Eimeria mulardi were studied. To appraise their susceptibility, fe male ducklings were infected with a dose of 75,000 oocysts per ducklin g (bringing about a clinical coccidiosis). In another group, to compar e the multiplication rates of the parasite in the three species of duc ks, thus assessing their receptivity, an infection with 750 oocysts pe r duckling was realized. Eimeria mulardi develops in the three species of ducks. In each case, a significant decrease in growth in the conta minated group vs. the control group was noted, even though the Muscovy and the mule ducks were more susceptible to the contamination.