Dose-dependent effects of dietary quercetin on cecal microbiota, hematological responses, and production efficiency in Arbor Acres broiler chickens

Dietary QC has a clear dose-dependent effect on the gut microbiota-immune-performance axis in broiler chickens. Supplementation at 5 mg/kg of feed is the optimal level, improving growth performance, feed efficiency, immune balance, and beneficial microbial populations without increasing pathogenic taxa. Higher supplementation levels may disturb microbial balance and raise the levels of potentially harmful bacteria. These findings support QC as a promising phytogenic alternative to antibiotic growth promoters and provide a scientific basis for its rational use in sustainable, antibiotic-free poultry production systems.