EFEITO ADITIVO DO TANINO NA ALIMENTAÇÃO ANIMAL

Abstract

It is known that plants produce anti-nutritional factors as a defense system, among which are secondary compounds, an example is tannin. These compounds have the function of protecting the plant from attacks by fungi, bacteria and herbivores. Tannins are phenolic compounds classified according to their chemical structure into hydrolysables and condensates. They are considered antinutritional due to their astringent character and their ability to complex with proteins making them unavailable to many animals, however, there are studies, mainly in the area of nutrition of ruminants, which has shown the use of tannin as an additive. This becomes an alternative to antibiotics in feedlot diets, due to the protein-tannin complex at neutral pH, which makes the protein unavailable in the rumen, increasing the protein supply in the small intestine, in the initial portion of the duodenum, changing the pH and promoting greater absorption of these nutrients, which increases the use of dietary protein, positively impacting the productivity and the immune system of the animals. Although studies on the use of tannin as an additive in animal feed are very scarce, the objective of the present review is to investigate the use of tannin in animal feed, and suggest the extent to which it can be used as an additive or when it becomes harmful in diets of animals.