In-vitro and in-vivo studies on digestion of dietary fibre components in a broiler chicken diet based on rye

In an in-vitro system, endogenous enzymes, as well as an added enzyme preparation, degraded both soluble and insoluble dietary fibre components in a diet based on rye endosperm, insoluble arabinose and xylose residues were not as efficiently degraded in vitro by the endogenous enzymes as the insoluble glucose residues. Broiler chickens were fed on the diet with or without the supplementary enzyme. Enzyme supplementation generally improved the apparent ileal digestibility of the insoluble dietary fibre components while soluble dietary fibres, especially arabinoxylans, were enriched in the ileal digesta leading to negative digestibility values. ¹H-NMR spectra of arabinoxylans in digesta from chickens in combination with sugar analyses corroborated the results from the in-vitro study which indicated that the enzyme preparation preferentially degraded the soluble mono-substituted xylose residues while un- and disubstituted xylose residues were enriched.