Dietary biotic supplementation modulates growth performance, anticoccidial efficacy, oxidative status, and intestinal histomorphology in Eimeria tenella–challenged broilers

This study investigated the comparative effects of dietary prebiotic, probiotic, and synbiotic supplementation on growth performance, anticoccidial efficacy, oxidative status, intestinal morphohistology, carcass traits, and meat quality of broilers experimentally challenged with Eimeria tenella (E. tenella). The novelty of this study lies in the simultaneous comparison of these three biotic strategies under the same controlled challenge model while integrating productive, physiological, intestinal, and meat quality responses. Broiler chicks were randomly allocated to six treatment groups consisting of a non-challenged control (CONN), a challenged control (CONP), an anticoccidial drug group supplemented with robenidine (0.5 g/kg of diet), and three challenged groups receiving either a prebiotic [Thepax®; an inactivated Saccharomyces cerevisiae yeast product rich in mannan oligosaccharides and β-glucans; 0.75 g/kg of diet], a probiotic [B-ACT®; Bacillus licheniformis DSM 28710, 3.2 × 10⁹ CFU/g; 0.50 g/kg of diet], or a synbiotic (Thepax® 0.75 g/kg + B-ACT® 0.50 g/kg of diet) supplementation. At 15 days of age, birds in the challenged groups were orally inoculated with sporulated E. tenella oocysts. Growth performance indices, anticoccidial indices, carcass traits, breast meat physicochemical properties, intestinal histomorphology, and antioxidant status were evaluated. The results showed that dietary supplementation with biotics, particularly probiotics and synbiotics, improved performance indices compared with CONP (P < 0.05). Supplemented birds also showed reduced lesion scores, oocyst excretion, and anticoccidial index (ACI). In addition, supplementation enhanced antioxidant capacity and improved intestinal morphology, as indicated by increased villus length and villus length-to-crypt depth ratio. Responses in carcass and meat quality traits were selective but generally favorable. In conclusion, dietary biotic supplementation, particularly probiotic and synbiotic, represents a promising nutritional strategy to mitigate the negative effects of E. tenella infection and enhance health and productivity in broilers.