Fatores anti-nutricionais de importância na nutrição animal: composição e função dos compostos secundários

Anti-nutritional factors are substances that even in vestigial state, reduce or prevent the use of a nutritional element. These anti-nutritional factors, most of which are secondary metabolites, which can be defined as compounds that have no recognized role in the maintenance of vital plant processes that synthesize them, in contrast, play an important role in the interaction of the plant with its environment. Anti-nutritional factors are usually not seen with "good eyes". Although the term anti-nutritional factors refer only to the "bad" characteristics of these substances, it is worth remembering that they are not only responsible for generating adverse effects. On the contrary, virtually all of them, if not all, are capable of conferring, also, possible beneficial effects to the animal organism. Some phenolic compounds of greater representativeness in the animal feed, are: tannins, lignins and gossypol. However, there are also saponins, mimosins, phytate, lectins, protease inhibitors and cyanogenic glycosides. All present in the plants, each with its particularity that will be explained throughout this review.