Equinews.com - Full Article
By Dr. Kathleen Crandell · April 5, 2011
Forage is perhaps the single most important ingredient in an endurance horse’s diet. Not only is it a major source of energy and essential nutrients, but also the presence of fiber in the digestive tract provides bulk to keep the tract functioning properly, keeps blood flowing to the tract even during exercise, stimulates thirst, and holds water and electrolytes in a reservoir.
Without the marvelous milieu of innumerable microbes populating the cecum and colon of the horse, forage would be indigestible. These microbes are not only responsible for breaking down the fiber in the forage but the end products of their fiber digestion are VFAs, which are sources of energy for the horse. The reason why the endurance horse is able to keep going for hours upon end has to do with the ability of these microbes to keep making VFAs that are absorbed into the bloodstream and distributed either to the liver (for conversion to glucose) or directly to the muscle cells to be used for aerobic energy formation. This, combined with the breaking down of glycogen stores in the muscle cells and the triglycerides from muscle and adipose tissue, makes for steady energy generation in the endurance horse...
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