Effect of dietary fibre on ileal digestibility and endogenous nitrogen losses in the pig

Dietary fibre is defined as a heterogenous mixture of structural and non-st ructural polysaccharides and lignin. A large number of investigations have been carried out to study the effect of dietary fibre on digestibility and endogenous tosses in pigs. Most of the authors reported that fibre content of the diet can impair apparent ileal digestibility of dietary nutrients, e ndogenous nitrogen and amino acid secretion and losses. Investigations duri ng the last few years have shown that the effects of dietary fibre differ w ith the source and nature of fibre and relate to their chemical composition as well as to their physico-chemical properties. The effect of pure cellul ose is rather low in contrast to other types of fibre (i.e. hulls, bran, en dosperm fibre or pectin). In experiments, the endogenous nitrogen losses we re almost twice as high after feeding barley endosperm fibre as compared to barley hulls (331 versus 180 mg N per 100 g dry matter intake (DMI)). It i s difficult to ascertain which physical or chemical properties are responsi ble for the effects.. The data presented in the review illustrate that diet ary fibre solubility, viscosity and water-holding capacity seem to be the m ost important factors influencing ileal digestibility of nutrients and endo genous losses in pigs. The latter is also affected by protein level of the diet and protein sources. (C) 2001 Elsevier Science B.V. All rights reserve d.