Abstract
Eimeria tenella is a protozoa which is a causative agent of avian cecal coccidiosis. The disease results in bleeding, diarrhea, weight losses, high morbidity and mortality in chickens. This study investigated lesion scores, oocysts output, hematological and histopathological changes of the 7 days life cycle of E. tenella. Fifty-six, broilers were randomly divided into 2 groups of which group 1 were uninfected and group 2 were infected with 2x104 E. tenella oocysts. Lesion scores and oocyst output of the infected group were significantly higher than in the uninfected group at 5, 6 and 7 dpi (p < 0.05). PCV was significantly lower than in the uninfected group at 3 to 7 dpi (p < 0.05). WBC count was significantly higher than in the uninfected group at 4 dpi (p < 0.05). Lymphocytes and heterophils were significantly higher than in the uninfected group at 4 dpi (p < 0.05). Monocytes were significantly higher than in the uninfected group from 3 to 5 dpi (p < 0.05). The developmental stages of E. tenella in cecum tissue during the 7 days life cycle included trophozoite at 2 dpi, first generation of schizonts at 3 dpi, secondary generation of merozoites and schizonts at 4 and 5 dpi and gametocytes and oocysts at 6 and 7 dpi. These finding suggest that monocytes were the most effective white blood cell on E. tenella infection and secondary generation schizonts was the most pathogenic developmental stage of E. tenella.
The Growth of Eimeria tenella: Characterization and Application of Quantitative Methods to Assess Sporozoite Invasion and Endogenous Development in Cell Culture
