The present study was conducted to compare different methods for experimental induction of necrotic enteritis (NE) in broiler chickens. 360 one-day-old male Cobb chickens were randomly assigned to 4 experimental groups with 6 replicates of 15 birds each. The experimental groups were: 1. Control diet (corn-soybean meal) group (Ctrl), 2. Ctrl + Eimeria + Clostridium perfringens co-inoculation group (ECp), 3. Ctrl + 25% corn replaced by wheat (W) + Clostridium perfringens inoculation group (WCp), and 4. W + Eimeria and Clostridium perfringens co-inoculation group (WECp). Birds were inoculated with Eimeria on day 11 and orally gavaged with C. perfringens on day 15. On days 17 and 24, two birds from each replicate of treatments were randomly selected, euthanized and the contents and segments of small intestine were carefully separated for micoflora, histomorphology/histopathology and lesion score indices evaluations. In a completely randomized design, data were analyzed by ANOVA using the GLM procedure method. The results of the present study showed that chickens receiving ECp and WECp significantly reduced body weight gain and negatively affected FCR at day 24. In addition, these chickens showed a severe morphological damage of the jejunal epithelium compared to other groups at days 17 and 24. The inclusion of ECp and WECp also increased the population of Clostridia and E. coli and decreased the Lactobacillus population in the ileum of broilers compared to other groups at days 17 and 24. The NE-inducing factors significantly affected lesion scores at d 17 and 24. Birds fed with ECp and WECp showed higher (P< 0.05) lesion scores in the jejunum and ileum compared to Ctrl received birds at 17 and 24 days of age, while WCp had no significant effects on lesion scores. In conclusion, the co-inclusion of Eimeria and C. perfringens with or without having a wheat-based diet can effectively reproduce NE in broilers and thus, can be proposed as reliable methods for future NE-related investigations.

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