Effects of Xylanase Supplementation and Citric Acid on Performance, Ileal Nutrients Digestibility, and Gene Expression of Intestinal Nutrient Transporters in Broilers Challenged with Clostridium perfringens

This study was conducted to evaluate the effects of xylanase and citric acid (CA) on growth, digesta pH, ileal populations of Clostridium perfringens and lactic acid bacteria, ileal nutrient digestibility, digestive enzyme activity, and mRNA expression of intestinal nutrient transporters in starter broilers challenged with C. perfringens. The experiment was conducted in a 2×2 factorial arrangement with two levels of CA (0 and 30 g/kg) and 2 levels of xylanase (0 and 200 mg/kg). Each of the four dietary treatments was fed to six replicate pens (15 birds/pen) between 0 and 21 d of age. Dietary CA significantly increased ADFI and ADG; meanwhile, xylanase addition led to a substantial reduction in FCR (P