Comparative effect of dietary supplements on the performance and severity of experimental Eimeria tenella infection in broiler chickens

The effect of the dietary supplements, sugarcane molasses (prebiotic), Antox® (probiotic) and Enflorax® (synbiotic), on gut health, performance and severity of infection with Eimeria tenella in broiler chickens was evaluated in this study. Ninety-day-old broiler chicks were divided into six groups (A, B, C, D, E and F). Groups B to F were challenged with Eimeria tenella (2.0 × 10 4 oocysts/chick). Groups C, D and E were supplemented from day old with prebiotic, probiotic and synbiotic, respectively, while F was administered amprolium. Groups A and B served as negative and positive controls, respectively. Feed intake and performance parameters were assessed weekly for each group. After infection clinical signs, morbidity and mortality rates were monitored alongside oocyst output, gross and microscopic caecal lesions. Infected chickens exhibited clinical signs 4 days post infection (dpi) with 100% morbidity in all infected groups. Infected groups showed significant ( P < 0.05) drop in feed intake and weight gain from 3 to 5 weeks of age. Feed conversion ratio was highest in B but lower in the supplemented groups. Oocyst output in faeces were significantly lower ( P < 0.05) in the supplemented groups compared with B. Macroscopic lesion scores 7 dpi were significantly lower in the supplemented groups compared with B, though group F had the lowest mean score. Histopathological examination of caeca tissues showed milder lesions in the supplemented groups. In conclusion, the supplements prebiotic, probiotic and synbiotic ameliorated the consequences of caecal coccidiosis in broiler chickens and therefore recommended for use in broiler production.