Performance indices, serum oxidative status, blood metabolites, and intestinal health of broiler chickens supplemented with a mixed phytogenic as an alternative to antibiotics

This research investigated the potential of a phytogenic mixture (PHY, composed of equal parts Acacia senegal, Thymus serpyllum, Tribulus terrestris, and Pulicaria jaubertii) as a natural alternative to antibiotics on performance indices, serum oxidative status, blood metabolites, and molecular and histological markers of intestinal health in broilers. A total of 840 one-day-old male broilers were assigned to five dietary groups: control (CON; basal diet), antibiotic reference (AN; basal diet + 0.1 g/kg oxytetracycline and neomycin), and three groups supplemented with PHY at 1.0, 2.0, and 3.0 g/kg (PHY1-3). The trial lasted 28 days, with data collected on growth, carcase traits, oxidative status, blood metabolites, intestinal health-related gene expression, and ileal histomorphology. The phytochemical profile identified 28 bioactive compounds in the PHY mixture, mainly carvacrol and thymol. Results showed that PHY supplementation improved body weight, weight gain, and feed conversion ratio (p < 0.05). The PHY2 and PHY3 groups had the highest slaughter and carcase weights (p < 0.05). Serum analysis indicated that PHY increased total antioxidant capacity while reducing malondialdehyde, superoxide dismutase, cholesterol, and triglycerides (p < 0.05). Additionally, PHY2 downregulated pro-inflammatory markers (interleukin-6 and tumour necrosis factor-alpha), and upregulated the expression of the occludin and interleukin-10 genes (p < 0.05). Histologically, the PHY mixture increased villus length, surface area, and the villus-to-crypt ratio (p < 0.05). In conclusion, the PHY mixture, particularly at 2.0 g/kg, serves as a superior alternative to traditional antibiotics by enhancing growth performance, strengthening the intestinal mucosal barrier, and improving systemic antioxidant status in broilers.