Wheat- and barley-based diets with or without additives influence broiler chicken performance, nutrient digestibility and intestinal microflora

BACKGROUND: To our knowledge, there is scant literature on comparative broiler response to cereal diets high in soluble non‐starch polysaccharides without or with enzyme, prebiotic, probiotic or synbiotic supplementation. In the present study, the effects of a wheat‐ and barley‐based diet with or without supplemental xylanase plus β‐glucanase, inulin, Enterococcus faecium or inulin plus Enterococcus faecium, on bird performance, digesta viscosity, nutrient digestibility and intestinal microflora were compared to a maize‐based diet. RESULTS: In comparison to a maize‐based diet, the wheat‐ and barley‐based diet reduced (P < 0.05) body weight gain and feed intake, but did not affect to the feed‐to‐gain ratio. Apparent digestibility of crude fat and various fatty acids were decreased (P < 0.05) as well as apparent metabolisable energy corrected to zero nitrogen retention content. There was an increase (P < 0.05) in the viscosity of jejunal digesta and in the caecal numbers of Escherichia coli and lactobacilli, and a decrease in the ileal numbers of E. coli and lactobacilli. Performance parameters and nutrient digestibility were not affected (P > 0.05) by dietary inclusion of the additives used, with the exception that exogenous enzyme improved (P < 0.05) the apparent digestibility of crude fat and decreased the viscosity of jejunal digesta. Enzyme and Enterococcus faecium supplementation increased intestinal lactic acid bacteria, whereas inulin addition reduced the number of E. coli (P < 0.05). Addition of inulin–Enterococcus faecium decreased E. coli and increased bifidobacteria numbers in the caeca. CONCLUSION: Enzyme supplementation to a wheat‐ and barley‐based diet significantly improved the apparent digestibility of dietary fat. All four additives had a beneficial effect on the intestinal microflora of broilers. Copyright © 2011 Society of Chemical Industry