Feeding fat to horses
Fat is a calorically dense, readily available and easily digestible source of energy for the horse. Although a combination of the more common feedstuffs used in the horse's ration might contain 3 - 5 % fat, a horse can easily utilize up to 20% fat in its diet. Among the horses that might benefit the most from having some of their grain replaced with fat or having extra energy as fat in their diets are horses that are exercised intensively, older horses that have difficulty maintaining their body weight and/or horses that have foundered in the past.
It is possible to increase the fat content of a horse's diet in a couple of different ways. You can select feedstuffs that are naturally higher in fat content e.g., rice bran or flax seed or you can add supplemental fats, e.g., vegetable oils, hydrolyzed animal fats or dry granular fats. Feedstuffs that are naturally higher in fat contribute other nutrients that must be taken into account. In contrast, the supplemental fats are greater than 98% fat and do not contribute other nutrients. The vegetable oils tend to be more palatable than animal fats and have less likelihood of containing impurities. Probably the most common method of increasing the fat content is to top dress the grain with corn oil or soybean oil. Increasing the fat content of the horse's diet should be done gradually.
It takes approximately 3 weeks for a horse to become adapted to a high fat diet. There have been no reports of adverse effects of feeding a high fat diet to a horse for an extended period of time, although it is important to not provide excess energy in the diet which will result in an obese horse.