Contrary to its typical effect on us humans, increasing the amount of fat in your horses’ rations can improve their health and performance. Unlike most Americans, who consume between 35 to 40 percent fat in their diets, domesticated horses are on the other end of the spectrum as most horse feeds contain just three to four percent fat.
For years it was thought that horses could not digest fat because they lack a gall bladder, which is commonly found in carnivores and omnivores. Where it exists, the gall bladder stores the bile needed to help digest fat. The horse, however, is an herbivore that secretes a continuous stream of bile that aids its ability to actually digest large amounts of dietary fat.
While humans benefit from consuming less fat and more complex carbohydrates (grains), those same carbs cause the greatest number of diet-related health problems in horses. Because of that, they can benefit from ingesting feed rations with a lower carbohydrate and higher fat content. This accomplishes two things:
First, fat contains 2.25 times as many calories as an equal weight of protein or carbohydrates and horses need the calories. And by feeding horses higher fat rations, fewer total pounds of feed are needed to meet their daily caloric requirements. Fewer pounds of feed means less gut fill and fewer pounds of bowel ballast ?that an equine athlete must carry around in competition.
Second, but perhaps more important, when a higher fat ration is mixed into the grain formula, there is less room in the mix for carbohydrates. This, of course, depends on how much fat is added, but in a concentrate of 8 to 10 percent fat, which is ta ypical high-fat ration, substantially fewer carbohydrates will exist than in a typical 3 percent fat ration.
By cutting back on the amount of carbohydrates, you lessen their effects on the horse’s hindgut, which is very sensitive to excess complex carbohydrates. And since colic is still the number-one cause of death in horses and complex carbohydrates such as starch are thought to increase the risk of colic, doing what you can to cut back on such ingredients is good for the horse. Because all grains contain starch, by feeding one that has a higher ratio of fat, you also lessen the risk of laminitis.
Broodmares and growing horses would especially benefit from higher fat rations. From late gestation through lactation, the broodmare requires a diet high in calories and fat is a safe nutrient source. Studies also show that widely varying glucose levels in growing horses that consume meals high in starch may play a role in developmental orthopedic disease (DOD). More lab work is needed, but it appears that balanced higher fat rations could provide more stable blood glucose levels and lessen the risk of bone disorders. It’s also important that higher fat rations fed to young horses provide adequate minerals and that these changes in diet are introduced carefully for slow, steady growth.
The equine athlete is another category of horse that can benefit from higher fat rations and not just because it reduces overall weight in the gut and intestine. Many studies have proven how muscle physiology will improve by adding fat to the diet of a competitive horse. Horses competing in anything from endurance to racing have realized the benefits of fat added to their diets. It has been found that the added fat helps stabilize blood glucose both during and after exercise. That’s good because at peak exercise, horses burn a stored sugar called glycogen for optimum performance. Feeding fat will spare these glycogen stores so there is more available at peak times. Recently, however, some researchers have come up with the possibility that feeding fat alters cellular metabolism somehow to favor glycogen burn during maximum exercise. Either way, both camps agree that the higher-fat ration is beneficial for performance animals.
“those carbs cause the greatest number of diet-related health problems in horses”
In an experimental model of the second day of a three-day event, Dr. David Kronfeld of the College of Agriculture at Virginia Tech University calculated that a horse on a high-fat diet will “generate 5 percent less heat, has 12 percent lower water requirement, needs 22 percent less feed intake and has 31 percent less fecal output and bowel ballast.”
So it’s easy to see that the benefits of high-fat content in feed goes beyond stabilizing blood sugar levels and more efficient energy production. In recent years, a great deal has also been learned about horses suffering from myositis or inflamed muscle tissues. There are various muscle pathologies and their causes generally stem from genetics and management. The good news is that most of these horses will improve by feeding higher fat rations.
Finally, research has also shown that even behavior can be improved by feeding higher fat rations. Horses fed more fat will exhibit less spontaneous activity and are less responsive to startling stimuli.
An important point to consider in feeding fat is the time it takes a horse to get used to the new diet and show results. Studies have confirmed that it will take 6 to 11 weeks for horses to fully achieve all the benefits of the added fat. Obviously, you can’t start a horse on a higher fat ration a few days before an event and expect to see any change.
While many people have added a few tablespoons of corn oil to a horse’s daily grain ration, for the metabolic benefits mentioned above a horse must consume a minimum of one pound or two cups of oil per day. Most horses, however, should be started with small amounts of oil before it is slowly increased to two cups per day.
Once acclimated, most horses find vegetable oils palatable. In fact, one study has shown that horses prefer corn oil, but other vegetable oils can also be used. While all the metabolic benefits can be safely achieved with animal fat as well, horses seem to prefer vegetable oils. (Many animal fats can become rancid and develop off flavors.) Recycled cooking oils should never be fed as they contain byproducts that can be unpalatable and unhealthy.
“Even behavior can be improved by feeding higher fat rations.”
But adding your own oil can be quite expensive—especially when you’re feeding larger numbers—and might result in a horse consuming less of a balanced grain ration. That, in turn, could mean a vitamin or mineral deficiency. Feed manufactures, on the other hand, can purchase oil much less expensively and they formulate their higher fat rations to contain adequate minerals and vitamins. To insure nutrient balance and for the best value, most barn managers would be wise to consider using higher fat rations available from reputable feed manufacturers.
There are very few reasons not to consider offering your horses a higher fat ration. From broodmares to race horses, fat is a nutrient that has a place on your farm. There are right and wrong ways to feed fat and you must feed it long enough to see the benefits. The skinny on fat is that it is a nutrient with many health and performance advantages.