Figure 1.

Effects of treatments on the expression of different genes in the jejunum of broiler chickens on day 24. Samples were analyzed using qPCR, and GAPDH and β-actin were used as the reference genes. Abbreviations as follows: IL-6, interleukin 6; IL-2, interleukin 2; MUC2, mucin 2; NC, negative control birds received a corn-soybean meal basal diet without AMPs, antibiotic and E. coli challenge; PC, positive control birds received NC diet and orally challenged with one ml of E. coli containing 1 × 10⁸ cfu/ml; Antibiotic, birds received PC diet and supplemented with 45 mg antibiotic (bacitracin methylene disalicylate)/kg diet; AMP, birds received PC diet and supplemented with 20 mg peptide/kg diet. The letters on the bar mean show significant difference (P < 0.05).