RELATIONSHIP BETWEEN THE LEVELS OF SOLUBLE NONSTARCH POLYSACCHARIDES AND THE APPARENT METABOLIZABLE ENERGY OF WHEATS ASSAYED IN BROILER-CHICKENS

The total arabinoxylan contents of 13 wheats grown in different regions of New South Wales, Australia, were determined. In addition, the wheats were sequentially extracted with cold 0.01 M NaCl, hot 0.01 M NaCl with a thermostable alpha-amylase, and cold 0.1 M NaOH. The nonstarch polysaccharide (NSP) content of each of the extracted fractions was determined. The nutritive quality of the wheats for broiler chickens was assessed by using a classical apparent metabolizable energy (AME) assay. The wheats ranged from 11.25 to 13.59 MJ/kg of dry matter. A highly significant negative correlation (r = -0.91, P < 0.0001) was found between AME values and the total NSP (which consisted mainly of arabinoxylan) removed from the wheats in the first two extractions. AME was not correlated with the alkaline-extracted NSP or total arabinoxylan levels. It was concluded that water-soluble NSP of wheat possesses antinutritive activity, while the water-insoluble NSP is probably biologically inert in the broiler chicken.