Experimental study on pathological changes and performance variations in Chickens challenged by Eimeria tenella under different genotype, age and nutrition status

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Addis Abeba University


Eimeria tenella is a Protozoa which is a causative agent of avian coccidiosis. The disease cause bleeding in the cecum, diarrhea, high morbidity and mortality in chickens. The experimental study was conducted from November 2020 to January 2022 at the ILRI poultry research facility in Addis Ababa. First experiment was aimed to investigate the effect of Eimeria infection at different feeding regimes on chicken pathological changes and productivity diversity in adult Sasso T451A and Bovans brown breeds. Chickens were infected with 1 x 104 oocysts of Eimeria tenella. Three factors; feeding regimes, challenges level and breeds of chicken were seen to evaluate the effects of parasite. The results showed that Bovans brow feeds deficient infected group had significantly higher (P < 0.05) gut lesions as compared to the control group. Production performance of feed restricted groups was significantly low as compared to optimum feeding but there was no significantly difference (P < 0.05) in production performance between infected and control groups. The second experimental study investigated oocysts output, lesion scores, PCV, pathological changes and production performance following artificial intubation of 3 x 104 of Eimeria tenella oocysts. The results show that lesion scores in Sasso was significantly higher (P < 0.05) than Bovans brown on day 4 post-infection. PCV of infected chicken was significantly (P < 0.05) decreased at day 8 post-infection in both breeds, similarly oocyst count and lesion score in the infected group of chicken was higher at day 8 than day 4 post-infection, this indicate that the infection was more severe at day 8 post-infection. Histopathological examination result of infected chicken by E. tenella was observed with infiltration of inflammatory cell in the cecum tissue. Therefore, the current result showed that the effect of E. tenella on infected chicken intestine had developed pathological lesions than non-infected groups of chickens.



Coccidia,young, optimum feeding, deficient feeding, infection, lesion score, oocyst count, E. tenella, Bovans brow breed, Sasso T451A breed