Introduction
On a worldwide basis corn and soybean meal are the
main staples in the diet for pigs and poultry, providing
most of the energy and nutrients needed. It is argued
that although other cereals, such as wheat, and byproducts,
such as rice bran and distiller’s grains, are used
as alternative feedstuffs in part of the world the quantities
available are not sufficient to replace corn and soybean
meal in the global pig and poultry industry [1].
This may be correct and may apply to the industrialized
livestock production, but may not be applicable to countries
where a major part of the livestock production relies
on smallholder farmers.
With more focus on small-scale family farming, in
order to improve food security and minimize the negative
impact on the environment and the climate, there
are opportunities for more diversified composition of
the diet with respect to feedstuffs included. Potential
feed resources used for animals in many countries in
Asia derive primarily from the vegetable foods and agroindustry
co-products, such as cassava leaves, sweet potato
vines, water spinach, rice bran, cassava residue,
brewer’s grain and tofu residue. They represent underutilized
feedstuffs, most having high fiber content, which
may impose limitations in their use in diets for monogastric
animals, in particular young animals, due to their
bulky nature and a limited capacity to ferment fiber [2].
Thus, in order to better utilize available fiber-rich feedstuffs
in the diet, their chemical and physical characteristics
has to be described and taken into account in feed
formulation.
Dietary fiber has an important role in pig and poultry
diets and a minimum level of dietary fiber has to be included
to maintain normal physiological function in the
digestive tract [3]. A major concern when including fiber
in diets for mono-gastric animals is that high dietary
fiber content is associated with decreased nutrient
utilization and low net energy values [4]. However, the
negative impact of dietary fiber on nutrient utilization
and net energy value will be determined by the fiber
properties and may differ considerably between fiber