Myths Concerning Feeding Fat to Endurance Horses
Fat is an unsuitable ingredient in the diets of endurance horses.
Fat is not only a perfectly acceptable component in the diets of all performance horses, it sometimes proves to be a necessary ingredient. Due to the intense work that endurance horses perform, many are unable to maintain optimal body condition when fed forages (pasture and hay) and traditional concentrates (textured or pelleted sweet feed). Because fats contain more than two times the energy of carbohydrates, they have become commonplace in the rations of successful endurance horses worldwide.
In fact, endurance horses fed fat may have an advantage over those that are not. As horses consume fat as part of their daily diets over a long period of time, their bodies become adept at using it as an energy source, allowing the horse to conserve more valuable fuels such as glycogen.
In a study conducted comparing the utilization of fat among breeds, researchers found that Arabians are most efficient at employing fat as an energy source.
At the 2005 World Endurance Championships, held in Dubai, nearly all of the horses were fed an identical concentrate supplied by the event’s sponsor, Sheikh Mohammed bin Rashid Al Maktoum. That feed was a high-fat formulation, and the finish times were blisteringly fast.
Because fat slows digestion, it adversely affects performance and should be avoided in the diets of endurance horses.
While investigating glycemic response (the measurement of blood sugar levels following a meal), nutritionists found that when corn oil was top-dressed to a grain meal, the stomach emptied slower than when fed grain without corn oil. Vegetable oils such as corn oil are commonly fed to equine athletes because they’re rich in calories.
Slower gastric emptying may be an advantage, not a detriment, to endurance horses. A vacant gastrointestinal tract creates few gut sounds, one of the telltale signs used by ride officials to determine if a horse is healthy enough to continue. By keeping ingesta flowing through the stomach and intestines, the risk of dehydration is minimized.
Additionally, slower digestion allows feed to remain in the stomach for slightly longer periods of time, thus keeping horses more comfortable. Coupled with the stress of competition, an empty stomach, and therefore an accumulation of unbuffered stomach acid, might set the stage for discomfort and diminished performance.
All fats are equal in their benefits to endurance horses.
Horses derive varying amounts of energy from different fat sources. For instance, vegetable oils contain virtually 100% fat. Rice bran, on the other hand, is 20% fat. Ease of feeding, palatability, nutrient density and other factors determine which fat supplement is best for an individual horse.
Researchers measured lactic acid accretion in horses fed the same diets except for one difference: an equal amount of fat was afforded by either rice bran or corn oil. Lactic acid is a useful gauge of fatigue in performance horses, so its measurement is an indication of endurance. The study revealed that horses had less lactic acid accumulation when fed rice bran, lending credence to the notion that endurance horses fed rice bran as an energy-dense supplement may have greater stamina than those fed corn oil.