Effects of dietary yeast β-glucans supplementation on growth performance, gut morphology, intestinal Clostridium perfringens population and immune response of broiler chickens challenged with necrotic enteritis

Necrotic enteritis (NE) is an enterotoxemic disease caused by Clostridium perfringens that results in substantial economic losses to the global poultry industry. This study was conducted to investigate the effects of dietary yeast beta-glucans (YG) on growth performances, gut morphology, intestinal C. perfringens population, endogenous antimicrobial peptide expression, and humoral immune response of broiler chickens infected with NE. A total of 240 one-day-old male broiler chicks were randomly assigned to a 2 x 2 factorial arrangements of treatments with two dietary glucan levels (0 or 200 mg/kg of diet) and two disease challenge status (control or NE challenged). NE model was induced via oral inoculation of mixed strains of Eimeria species at 12 d of age, followed by an oral inoculation with C perfringens at 16, 17 and 18 d of age. Infected birds fed the glucan-supplemented diet had significantly increased body weight (13 to 21 d, 0 to 42 d), significantly improved feed efficiency (13 to 21 d, 21 to 42 d), increased antibody levels against C perfringens and improved villi height and villi height to crypt depth ratio. In addition, infected birds that were supplemented with YG had markedly reduced intestinal C perfringens numbers, and NE gut lesion scores compared with infected birds fed unsupplemented diet. Moreover, YG supplementation increased gene expression of Cath-2, AvBD-4, and AvBD-10 expression at the early infection stage and Cath-1, Cath-2, and AvBD-1 at the later infection stage in the gut compared with unsupplemented birds. Decreased AvBD-10 and LEAP-2 mRNA levels were observed at the later infection stage in the glucan-supplemented birds when compared with that in the non-supplemented control group. In conclusion, yeast beta-glucans supplementation improved intestinal health of broiler birds challenged with C perfringens-induced necrotic enteritis. (C) 2016 Elsevier B.V. All rights reserved.