Non-starch plant polysaccharides in broiler nutrition – towards a physiologically valid approach to their determination

Abstract

The physicochemical properties of non-starch polysaccharides (NSPs) are responsible for their antinutritive activities in the broiler chicken. In particular, soluble viscous NSPs depress the digestibilities of protein, starch and fat. On the other hand, insoluble and non-viscous NSPs may have a beneficial effect. Fat digestion is used here to illustrate how the physicochemical properties of NSP may interfere with digestion and absorption. It is suggested that the gut microflora can mediate the antinutritive effects of soluble and viscous NSP. It is concluded that the determinations of crude fibre and/or acid detergent fibre and neutral detergent fibre in feedstuffs are not appropriate for predicting and understanding the physiological action of NSPs in broilers. The determination of the in vitro solubility of NSP and the viscosity of the feed ingredient could become of major importance for ‘antinutritional’ evaluation. More research needs to be conducted to study the interactions of NSPs with the microbial activity in the intestinal tract of the broiler chicken.

Keywords:

• Broilers
• fibre
• non-starch polysaccharides
• nutrition
• physiology