Distribution of oocysts, sporocysts and sporozoites of Eimeria tenella and Eimeria maxima in the digestive tract of chicken

Abstract

The distribution of oocysts, sporocysts and sporozoites of Eimeria tenella and Eimeria maxima in the digestive tract of chicken and in excreta was investigated. At 1 h after the oral inoculation of E. tenella oocysts, the number of sporocysts in the cerum was 3.4×106 and decreased gradually thereafter, and the number of sporozoites in the serum increased and remained at a high level until 12 h after the innoculation. Small numbers of sporocysts and sporozoites of E. tenella were found in other intestinal sites. A great number of E. maxima sporozoites was found, especially in the jejunum, 2 h after the inoculation. The findings that the largest populations of sporozoites of E. tenella and E. maxima were found in the cerum and the jejunum, respectively, indicate that the site specificity of sporozoite invasion for each species is determined before the invasion takes place. © 1992.