Wood vinegar as a natural alternative to antibiotics: Effects on cecal microbiota, antioxidant status, and nutrient digestibility in broiler chickens.

Abstract

Background and aim: Antibiotic resistance has spurred interest in alternative feed additives for poultry. Wood vinegar (WV), a by-product of plant pyrolysis, contains bioactive compounds with antioxidant and antimicrobial properties. This study aimed to evaluate the effects of WV supplementation through drinking water on the cecal microbial population, volatile fatty acid (VFA) concentrations, antioxidant enzyme activity, and apparent ileal nutrient digestibility in broiler chickens.

Materials and methods: A total of 432 1-day-old male Cobb 500 broiler chicks were randomly assigned to six groups (n = 72 per group; 6 replicates of 12 birds each). Treatments included a negative control (T₁), a positive control with 0.02% oxytetracycline (T₂), and WV-supplemented groups at dilution ratios of 1:100 (T₃), 1:200 (T₄), 1:500 (T₅), and 1:1000 (T₆) in drinking water. The experiment lasted 35 days. Plasma antioxidant enzymes (superoxide dismutase [SOD], catalase [CAT], glutathione peroxidase [GPx], total antioxidant capacity [T-AOC]), VFA profiles, ileal digestibility (crude protein [CP], ash, ether extract [EE]), and cecal microbial populations were assessed. Statistical analysis was performed using the General Linear Model and Duncan's multiple range tests (p < 0.05).

Results: WV supplementation enhanced antioxidant status, with significant increases in GPx (T₅ and T₆) and T-AOC (T₆), while CAT and SOD remained unaffected. T₅ significantly elevated acetic, butyric, and total VFA levels. WV-treated birds (T₃-T₆) showed reduced Salmonella, Escherichia coli, and Enterobacteria counts and increased bifidobacteria and total bacteria compared with controls. T₄ showed the highest digestibility of CP, while T₅ significantly improved ash and EE digestibility.

Conclusion: WV supplementation, particularly at a 1:200 dilution (T₄), effectively improved gut microbial balance, enhanced antioxidant enzyme activity, and promoted nutrient digestibility. These results support WV as a viable natural alternative to antibiotic growth promoters in broiler production.