THE INHIBITION OF NUTRIENT DIGESTION BY WHEAT PENTOSANS

Two pentosan-rich fractions (water-extractable, WEP, and alkali-extractable, AEP) were isolated from a wheat milling by-product. When both WEP and AEP were added to a commercial-type broiler diet the apparent metabolizable energy (AME), nitrogen retention, feed utilization and growth of broilers were significantly (P < 0.001) depressed. These depressions were closely correlated (P < 0.001) to the level of pentosans in the diets. At the highest level of inclusion of pentosans (equivalent to 40 g arabinoxylans as AEP/kg) the ileal digestibilities of starch, protein and lipid were decreased by 14.6, 18.7 and 25.8% respectively.