Efficacy of microencapsulated organic acids-cinnamon blend as alternatives to antibiotic growth promoters: Assessing performance, gut histomorphometry, ileal digestibility, immunity, and antioxidant status in broilers.

This study evaluated a microencapsulated blend of organic acids and cinnamon extract (OAs-C) as a natural alternative to antibiotic growth promoters. A total of 360 day-old male Ross 308 chicks were assigned to four dietary treatments: a negative control (NC), a positive control with antibiotics (PC), and two supplement levels at 1.5 or 3.0 g/kg. The 3.0 g/kg dose significantly increased body weight gain (BWG; P = 0.005) and improved the cumulative FCR (P = 0.014). Feed intake (FI), Newcastle disease virus antibody (NDV) titers or serum antioxidant parameters, specifically malondialdehyde (MDA), total antioxidant capacity (TAC), superoxide dismutase (SOD), and glutathione peroxidase (GPx) remained statistically unaffected by the OAs-C treatments (P > 0.05). Morphometric analysis of the jejunum revealed that villus height (VH) and villus width (VW) were not significantly influenced by the 1.5 and 3 g/kg OAs-C. The PC and 1.5 g/kg groups significantly reduced jejunal crypt depth (CD; P = 0.033). Compared to the control, birds supplemented with 1.5 g/kg OAs-C achieved the highest VH/CD ratio (quadratic P-value = 0.021). Furthermore, the 3.0 g/kg inclusion level significantly expanded the villus surface area (VSA) with linear (P = 0.030) trend. Apparent ileal Ash digestibility showed significant linear (P = 0.041) and quadratic (P = 0.038) effects. Supplementation with 3.0 g/kg OAs-C induced significant linear and quadratic increases (P < 0.01) in the digestibility of crude protein (CP) and calcium (Ca). Regarding apparent ileal phosphorus (P) digestibility, a significant quadratic response (P < 0.001) was observed, with the 1.5 g/kg dose providing the optimal result. In conclusion, the microencapsulated OAs-C blend enhances broiler growth and feed efficiency primarily by optimizing intestine morphology and improving nutrient utilization.