Abstract
SUMMARY: A comparison has been made between the methods for crude fibre (CF) and acid-detergent fibre (MADF) determination. In diets containing 10 to 70 % hay with or without 8 % tallow (T) or maize oil (MO), a highly significant (P < 0·001) correlation of r = 0·95 was observed between CF and MADF estimates. This high correlation confirmed a similar relationship found in silages, concentrate feeds and also hays. Similarly for rumen digesta, a correlation of r = 0·93 was found (P < 0·001). The equation for predicting CF from MADF calculated from diets and digesta data together was CF = 0·503+0·848 (+0030) MADF and the residual variation found was sufficiently small to provide useful estimates.