KER.Equinews.com - Full Article
By Kentucky Equine Research Staff · March 2, 2016
Horses derive energy from various components of their diets, namely starch, fat, fiber, and protein. An idle mature horse likely obtains most of his dietary energy from fiber-rich feedstuffs such as pasture and hay. Fiber is fermented in the hindgut and energy created for maintenance of body processes. For horses involved in regular athletic activity, a fiber-only diet will probably not provide enough fuel for the combined toll of exercise and maintenance of body weight, so other energy sources must be added. Of those others mentioned previously—starch, fat, fiber, and protein—protein is least efficient at fueling work.
If the protein intake of a performance horse exceeds its requirement, the superfluous protein can be used as a source of energy. The amino acids from the extra protein are broken down by the liver, and the carbon skeletons that are left are oxidized to produce adenosine triphosphate (ATP), the molecule used to power muscular activity, or used to make glucose or fat. The nitrogen from the protein is excreted in the urine as urea and changed to ammonia as it interacts with environmental microorganisms...
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