Immune responses to dietary inclusion of prebiotic-based mannan-oligosaccharide and β-glucan in broiler chicks challenged with Salmonella enteritidis

This study was performed to evaluate the effect of dietary prebiotic-based mannan-oligosaccharide and \beta -glucan on immune organ weights, white blood cell profiles, and antibody titers against Newcastle and infectious bursal disease viruses in broiler chicks challenged with Salmonella enteritidis. The addition of prebiotics to the diet of unchallenged chicks had no effect on antibody titers and other measured parameters. Salmonella challenging decreased the relative weights of immune organs, increased white blood cells and the heterophil-to-lymphocyte ratio, and decreased the antibody titers against Newcastle and infectious bursal disease viruses. Inclusion of prebiotics to the diet of challenged chicks increased the relative weight of the spleen, decreased the heterophil-to-lymphocyte ratio, and increased antibody titers. The results showed that dietary inclusion of prebiotic-based mannan-oligosaccharide and \beta -glucan has no significant effect on immune parameters on chicks in the noninfected group, but it displays an efficacy on chicks in the group infected with pathogens and can improve the immune responses and health of infected chicks.