Physicochemical properties to support fibre characterization in monogastric animal nutrition

BACKGROUND The aim of the study was to rank conventionally used fibre rich feeds for their physicochemical properties and detect possible correlation between analytical fibre determinations. A total of 22 samples were analysed for proximate fibre values, soluble dietary fibre (SDF), insoluble dietary fibre (IDF), crude protein (CP) and crude ash (CA). Physicochemical properties were determined in vitro by hydration capacity (HC) [water holding capacity (WHC), water binding capacity (WBC), swelling property (SwP)] and buffering capacity [linear buffering rate (LBR)]. RESULTS Fibre content and physicochemical properties varied markedly between the samples. HC was highest for beet pulp and lowest for rice and millet bran. Buffering capacity expressed minimum values for lignocelluloses and maximum values for rape seed hulls. The correlation of methods was positively between WBC, WHC and SwP (r ≤ 0.89; P ≤ 0.003) but not significant for HC and buffering capacity. SwP negatively correlated with crude fibre (CF), neutral detergent fibre (aNDFOM) and IDF (r ≤ −0.48; P ≤ 0.05). WBC and SwP positively correlated with SDF (r ≤ 0.63; P ≤ 0.04). LBR was negatively correlated with CF, aNDFOM, IDF and total dietary fibre (r ≤ −0.55; P ≤ 0.02), but positively with CP (r = 0.53; P = 0.01). CONCLUSION The determination of physicochemical properties is applicable to rank fibre rich feeds, some correlations between fibre analytical measurements and physicochemical properties were detected. © 2019 The Authors. Journal of the Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry