Effects of oregano essential oil and attapulgite on growth performance, intestinal microbiota and morphometry in broilers

Two experiments were conducted to study the effects of a blend of oregano essential oil (OEO) (as a source of natural antibacterial growth-promoting substances) and attapulgite (as a source of toxin-binder and as an antidiarrhoeal agent) on growth performance, intestinal microbiota, and intestinal morphometry in broiler chickens (Ross-308). In the first trial, the control group was fed a basal diet without antibiotic growth promoters, and the experimental group was fed the basal diet supplemented with 5% OEO (OEO) (Ecodiar (R) powder at 150 g/tn) and 80% attapulgite 80% (Ultrafed (R) at 6 kg/tn) blend. In the second trial, the experimental group was given the basal diet supplemented with 5% OEO (Ecodiar powder at 300 g/tn) and 80% attapulgite (Ultrafed at 3 kg/tn) blend. Intestinal microbiota was enumerated by conventional techniques with selective agar media at the end of the trial at both ileum and caecum, and intestinal morphology was assessed in the duodenum, jejunum and ileum. Results showed that in the first trial, despite the positive impact on daily gain and feed-to-gain ratio, growth performance was not affected by the blend with OEO and attapulgite. Furthermore, no effect was found on intestinal morphometry. However, the counts of lactic acid bacteria were increased significantly, and coliforms were decreased in caecal contents. In the second trial, a positive impact was noticed on daily gain and feed-to-gain ratio by the high OEO and low attapulgite blend. Dietary supplementation of OEO and attapulgite increased ileal villus height and lactic acid bacteria significantly and reduced coliforms in ileal and caecal contents compared with the control group. In conclusion, the combination of OEO at 15 mg/kg and attapulgite at 2.4 g/kg exerted a positive effect on growth performance, ilea! villus height and intestinal microbiota of broilers.