A favorite pastime of humans and horses alike is to eat. Our world view of eating revolves around fundamental expectations of the types of food we eat, how these foods make us feel, and how different foods are processed through our bodies. Unlike our human intestinal constitution, the horse has a unique intestinal structure and function for processing feed. Comparing equine digestive function with human or small animal function leads to misconceptions, and, hence, mismanagement.

To understand how to best accommodate equine digestive health, it helps to briefly examine the structural function of a horse’s bowel. As strict herbivores, horses have evolved a complex intestinal arrangement that focuses most of digestion in the enormous hindgut. It is there, in the large intestine, that the bulk of nutrients and fluids are absorbed. Because horses thrive on eating plant fiber materials, the entire intestinal tract has developed mechanisms to process cellulose: Huge and numerous grinding teeth crush plant fibers, which undergo limited digestion in the small intestine and pass to the large intestine, where resident bacteria (microflora) digest fiber (cellulose) to release nutrients.

It is said that to keep a horse healthy, one must direct attention to keeping hindgut bacterial microflora healthy. So, how is this done?

Fiber, Fiber, and More Fiber

The mainstay of any equine diet should be fiber–you should focus on presenting the intestinal tract with ample fiber to help the system do its work. The act of eating and the intake of forage are major stimuli for active gastrointestinal (GI) motility. In contrast, fasting lead