The horse is a monogastric herbivorous that has a digestive tract composed by a smallstomach and a well-developed small and large intestine. So, horse’s digestion hascharacteristics that combine the advantages of enzymatic digestion and microbialdigestion. The digestive physiology of equines is characterized by a quick and intenseenzymatic digestion in small intestine, and a long and intense microbial fermentationprocess in large intestine. The horse reveals a high capacity to consume roughagesbecause microbial population of the large intestine is able to use high-fiber feeds andrecycle the nitrogen. Horses have acquired the capacity to consume high amounts offorage, making sure that their energy needs were coverage, in order to balance the lowdigestibility of this type of feed.