Background: The study was undertaken to determine the efficiency of supplementation of antimicrobial peptide on growth performance, serum biochemistry, intestinal morphology, antioxidant status and gene expression of cytokines and tight junction proteins in broiler chicks as an alternative to antibiotic growth promoters that impart residues in broiler meat. Methods: The FCR was calculated by dividing the respective feed intake of chicks by weight gain during the respective period. Two broiler chicks were randomly selected from each replicate based on the average body weight of the corresponding replicate. After sacrifice, blood for serum and sections of small intestine were collected for the assessment of intestinal morphology, antioxidant activity measurement and gene expression of cytokines and tight junction proteins. Result: The results revealed that supplementation of antimicrobial peptide significantly improved the overall weight gain of broiler chicks compared to the NC. There was a significant increase in the activities of intestinal superoxide dismutase and glutathione peroxidase in the antimicrobial peptide supplemented group. AMP significantly modulates the gene expression of intestinal cytokines (IL-17A, IFN-α, IFN-γ and IL-10) and tight junction protein genes. These results indicate that antimicrobial peptide supplementation had beneficial effects on growth performance and intestinal health in broilers.

Background: Misuse of antibiotics has led to bacterial antibiotic resistance and antibiotic residues in meat and egg. The aim of this study was to assess the effect of dietary supplementation of chicken intestinal-derived antimicrobial peptide as an alternative to antibiotic growth promoters on the immune response of birds. Methods: Immune organs of randomly selected birds were collected for immune organ index. Blood samples were collected for serum to measure the antibody titre against infectious bursal disease and Newcastle disease virus using ELISA. Whole blood was collected to study the cytokine gene expression (IL-17A, IFN-α, IFN-γ, TGF-β, IL-10) using Real-time PCR. Result: Antimicrobial peptide supplementation had no significant effect (P greater than 0.05) on the immune organ index and serum antibody Titre against infectious bursal disease and Newcastle disease virus on the 21st and 35th days of the study. However, it significantly (P less than 0.01) downregulated the gene expression of pro-inflammatory cytokines viz., IL-17A, IFN-α, IFN-γ and upregulated IL-10 expression in peripheral blood mononuclear cells. The results suggest that supplementation of antimicrobial peptide at a level of 100 mg/kg diet improved the cell-mediated immune response in broiler chicks but would not have been sufficient to enhance the humoral immune response and immune organ index in chicks.