Dietary gallic acid facilitate growth performance, improve slaughter performance through enhanced intestinal function in yellow-feathered broiler

Regarding the antibacterial and antioxidant properties of Gallic acid (GA), it was used as feed additive to evaluate intestinal health and production performance of broilers. Yellow-feathered male broilers (375 birds at 21-day-old) with similar body weight were randomly divided into five groups, each with five replicates and 15 chickens per replicate. Chickens were fed basal diet with 0, 50, 100, 150, and 200 mg/kg GA for 42 days. Then, chickens were slaughtered for slaughter performance, intestinal function, gut microbiota measurement. Compared to the control group, supplementation with 150 mg/kg GA significantly increased body weight at 42, 56, and 63 days of age (P < 0.05), significantly increased average daily gain (ADG) and reduced feed conversion ratio (FCR) during the growth phase (P < 0.05), and increased abundances of Firmicutes and decreased abundances of Bacteroidetes (P < 0.05). Supplementation with both 100 and 150 mg/kg GA significantly decreased abdominal fat rate and increased breast muscle rate (P < 0.05), and enhanced expression of IL-1β, TNF-a, TLR4, HSP70, mucin2 and Nrf2 (P < 0.05). In conclusion, GA (150 mg/kg) was associated with improved growth and slaughter performance and with changes in intestinal gene expression and cecal microbiota compositions.