Increasing amounts of muscle protein are consumed as the horse 's dependence on these fuels climbs. Finally, at the end stage of the fuel supply cycle, fat becomes the horse s primary energy source. If the horse is willing, we can add more fat to the diet. If we add three or four times the fat found in natural forage, the horse will change his metabolism to burn the extra fat. That can help spare glycogen stores in the muscles and liver for future use.
Fats are less efficient than glucose.
It usually takes more energy to burn fats than glucose or amino acids. Fats are also less stable than carbohydrates. Storing, mobilizing, and oxidizing fats creates higher levels of oxidative radicals. To limit damage from these oxidants, nutritionists recommend extra antioxidant support for high-fat diets. Horses evolved for millions of years eating the prime source of glucose, plant carbohydrates.