Influence of cereal non-starch polysaccharides and enzyme supplementation on digestion site and gut environment in weaned piglets

The partial degradation of beta-glucans and arabinoxylans in cereal-based diets by specific enzymes may improve the nutritional value for the pig. Therefore, the aim of the present study was to examine the influence of diets with different contents of cereal non-starch polysaccharides (NSP) without or with supplementation of the enzymes endo-(1-3),(1-4)-beta-glucanase and endo-(1-4)-beta-xylanase on digestibility and gut environment. A total of 32 male castrated (Y x L) piglets from eight litters was allocated to a diet high in NSP (H) or low in NSP (L), each diet without and with enzyme supplementation (1 g/kg diet each of beta-glucanase and beta-xylanase). Diet H contained 874 g cereals and 197 g NSP/kg DM and was composed of triticale:wheat bran: oats: wheat: barley in relative proportions of 0.367:0.341:0.143:0.120:0.029. Diet L contained 433 g cereals and 106 g NSP/kg DM and the cereal part was composed of triticale:wheat bran: oats: barley: wheat in relative proportions of 0.432:0.360:0.120:0.048:0.039. The trial started before weaning when the piglets were aged 27-28 days (live weight 8.9 +/- 0.6 kg). After 14 days on the respective diets (mean live weight 11.6 +/- 1.3 kg) the piglets were euthanised and digesta samples collected from the Gastro-intestinal tract. The high NSP level resulted in increased daily gain (P < 0.05), decreased digestibility (P < 0.05) of organic matter in the ileum, caecum, colon and rectum, decreased pH (P < 0.05) in the caecum and colon and increased content (P < 0.05) of total organic acids (OA) in the stomach and ileum. Furthermore, the high NSP level resulted in an increased (P < 0.05) molar proportion of lactic acid (of total OA) in the stomach and ileum and an increased (P < 0.05) molar proportion of propionic and butyric acid (of short chain fatty acids, SCFA) in the ileum. Enzyme supplementation increased (P < 0.05) the molar proportion of lactic acid (of total OA) in the ileum and decreased (P < 0.05) the molar proportion of acetic acid (of SCFA) in the ileum. In conclusion, dietary NSP level influenced the digestibility of organic matter, as well as the gut environment. However, the digestibility of dietary fibre components was unaffected by NSP level. An increased dietary content of NSP and supplementation with fibre degrading enzymes influenced the distribution of OA in the ileum, indicating a shift in dominating bacteria. (C) 2004 Elsevier B.V. All rights reserved.