Abstract:
Over recent years, the monogastric animal industry has witnessed an increase in feed
prices due to several factors, and this trend is likely to continue. The hike in feed prices is mostly
due to extreme competition over commonly used conventional ingredients. For this trend to be
subdued, alternative ingredients of both plant and animal origin need to be sourced. These types of
ingredients are investigated with the aim of substituting all or some of the conventional compounds.
However, alternative ingredients often have a double-edged sword e ect, in that they can supply
animals with the necessary nutrients although they contain antinutritional factors such as tannins.
Tannins are complex secondary metabolites commonly present in the plant kingdom, known to bind
with protein and make it unavailable; however, recently they have been proven to have the potential
to replace conventional ingredients, in addition to their health benefits, particularly the control of
zoonotic pathogens such as Salmonella. Thus, the purpose of this review is to (1) classify the types of
tannins present in alternative feed ingredients, and (2) outline the e ects and benefits of tannins in
monogastric animals. Several processing methods have been reported to reduce tannins in diets for
monogastric animals; furthermore, these need to be cost-e ective. It can thus be concluded that the
level of inclusion of tannins in diets will depend on the type of ingredient and the animal species.
