The poultry industry has several disease challenges; coccidiosis is considered one of the most dangerous 18 parasitic diseases. Six-hundred Ross 308 male broiler chicks (average initial body weight 41.5 g) were 19 allocated to six groups: negative control uninfected (NCO); positive control infected with Eimeria (PCO); or 20 positive control supplemented with diclazuril (0.2 g/kg diet, DIC); two-strains probiotic (2 g/ kg diet, PRO); 21 oregano essential oil (300 mg/ kg diet, OEO); a combination of 2 g probiotic and 300 mg oregano essential oil 22 (POE). At day 15, all groups except NCO were inoculated via oral gavage with oocysts of mixed Eimeria spp. 23 Our results indicated that the infected chickens with mixed Eimeria (PCO) exhibited lower growth 24 performance, higher mortality rate, and increased oocyst shedding (P < 0.05), in addition to deterioration of 25 immune-oxidative status in broilers on 35 d. On the contrary, Eimeria-infected chickens fed on a diet 26 supplemented with DIC, PRO, OEO, and POE showed improved growth performance (P < 0.05) and decreased 27 mortality and oocyst shedding. Moreover, feeding chickens on POE enhanced body weight gain, feed 28 conversion ratio, crude protein digestibility, and dressing. Furthermore, POE supplements supported 29 immunity and antioxidant status by increasing IgA, IgG, IL-10, and SOD levels (P < 0.05) and reducing IL-6 30 and MDA levels. Additionally, adding POE altered the gut microbiota structure via an increasing Lactobacillus 31 count and decreasing C. perfringens, E. coli, and Coliforms count. Notably, POE supplements also reduced 32 oocyst shedding and lesion scores. Moreover, the up-regulated nutrient transporters, including the 33
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expressions of cationic amino acid transporter-1 (CAT-1) and mucin-2 (MUC-2) were up-regulated (P |
