Sporulation of Eimeria maxima oocysts in litter with different moisture contents

The aim of this study was to determine if the sporulation of Eimeria maxima oocysts was affected by the moisture content of the litter. Fresh feces we re collected from chickens experimentally infected with E. maxima. The fece s were mixed with dried wood shavings and different amounts of water to obt ain final moisture contents of 16, 42, and 62% and a final oocyst concentra tion of 5,000 per g of mixture. The samples were kept at 23 C and 75% relat ive humidity and were thoroughly aerated every 12 h. Oocysts kept under ord inary laboratory sporulation conditions in 2% wt/vol aqueous potassium dich romate at 27 C were used as a standard for optimal sporulation. The proport ion of sporulated oocysts was determined microscopically every 12 h. Sporulation of E. maxima was most efficient under the driest conditions stu died (16% moisture content), and poorest in the samples with the highest mo isture content (62%). Even though the differences may not have resulted fro m a direct effect of humidity on the oocysts, but more likely resulted from limited oxygen in the moister substrates, it is clear that sporulation is not favored by moist litter.