The horse is a posterior fermenter. When feed enters the stomach of the horse, it is mixed with digestive acids and enzymes to start the process of nutrient absorption. The workhorse is the small intestine – 80-90 percent of the fats, amino acids, and vitamins are absorbed through the small intestine. As ingredients pass into the small intestine, after about 20 minutes in the stomach, they are mixed with enzymes that break them down for absorption through the intestinal villi. It takes between 6-8 hours for the feed to pass through the small intestine. Once feed enters the large intestine it is the beneficial bacteria that go to work breaking down cellulose, lignans, seeds and grains to obtain any remaining nutrients prior to passing into the rectum.