Published online by Cambridge University Press: 18 August 2016
The disappearance of neutral-detergent fibre (NDF) from six fibrous foods (lucerne hay, NaOH-treated barley straw, olive leaves, paprika meal, soya-bean hulls and sunflower hulls) when incubated in the rumen of sheep in nylon bags was investigated. Source of fibre, time of incubation and its interaction had a significant (P < 0·01) effect on NDF degradation. Stepwise regression analysis showed that the best single predictor for NDF degradation rate was the hemicellulose fraction of NDF (HEMndf). The variables selected to predict potential degradability and degradability of NDF at 72 h were the proportions of acid-detergent lignin in NDF (ADLndf, first step) and of acid-detergent cutin in ADL (ADCadl, second step). For NDF degradability at 12 h, the variables selected were the proportions of HEMndf, ADLndf and ADCadl, in the first, second and third step, respectively. The results showed that ADC is an important component to understand NDF degradability at both 12 and 72 h.