title: Effects of viscosity and fermentability of dietary fibre on nutrient digestibility and digesta characteristics in ileal-cannulated grower pigs.
abstract: Relative contributions of two functional properties, viscosity and fermentability of dietary fibre, on apparent ileal digestibility (AID), apparent total tract digestibility (ATTD), digesta passage rate, N retention and SCFA concentration have not been established. Thus, eight ileal-cannulated pigs randomised in a double 4 × 4 Latin square were fed four diets based on maize starch and casein supplemented with 5 % of actual fibre in a 2 × 2 factorial arrangement: low-fermentable, low-viscous cellulose (CEL); low-fermentable, high-viscous carboxymethylcellulose (CMC); high-fermentable, low-viscous oat β-glucan (LBG); high-fermentable, high-viscous oat β-glucan (HBG). Viscosity and fermentability interacted to affect (P < 0·001) digesta viscosity and AID and ATTD of nutrients. These properties tended to interact to affect (P < 0·10) digesta passage rate and butyrate. Pigs fed the CMC diet had the lowest (P < 0·05) digesta passage rate and the highest (P < 0·001) AID of energy, crude protein and DM, and ATTD of energy and DM. Post-ileal DM digestibility was highest (P < 0·001) for pigs fed the CEL and HBG diets. Post-ileal DM digestibility had a negative, curvilinear relationship with the AID of energy and crude protein (R2 0·85 and 0·72, respectively; P < 0·001). Digesta viscosity had a less strong relationship with the AID of energy and crude protein (R2 0·45 and 0·36, respectively; P < 0·001). In conclusion, high-viscous, low-fermentable dietary fibre increases the proportion of a diet that is digested in the small intestine by reducing digesta passage rate.
authors.affiliation: Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB, Canada.
authors.forename: Seema
authors.initials: S
authors.lastname: Hooda
authors.forename: Barbara U
authors.initials: BU
authors.lastname: Metzler-Zebeli
authors.forename: Thavaratnam
authors.initials: T
authors.lastname: Vasanthan
authors.forename: Ruurd T
authors.initials: RT
authors.lastname: Zijlstra
mesh_terms: D000818:Animals; D002404:Catheterization; D004043:Dietary Fiber / Q000008:administration & dosage*; D004063:Digestion; D005285:Fermentation; D007082:Ileum / Q000473:pathology; D013552:Swine / Q000502:physiology*; D014783:Viscosity