Comparative Analysis of Evaluation Parameters in Broiler Chickens Infected With Major Parasitic Species of Eimeria 

Abstract

Background: Avian coccidiosis is a major disease within the poultry industry caused by species of Eimeria, an intestinal protozoan parasite. Body weight gain, intestinal lesion score, and fecal oocyst shedding are parameters that have been used to assess the protective effects of various treatments in Eimeria-infected chickens. The objective of this study was to compare the aforementioned parameters in broiler chickens infected with major parasitic species of Eimeria, such as E. acervulina, E. maxima and E. tenella. Results: The results of the body weight gain, intestinal lesion score, and fecal oocyst shedding showed similar patterns between female and male broilers infected with Eimeria species. However, there was a difference in body weight gain between normal females and males, and also between Eimeria-infected females and males. When broilers were infected with 1×104 sporulated oocysts of Eimeria species, each Eimeria species induced distinct changes in body weight gain, lesion score, and fecal oocyst shedding. In addition, a lesion score of approximately 3 was more closely related to body weight gain than a lesion score of approximately 2. Conclusion: These results suggest that certain levels of lesion severity are more closely related to body weight gain.