Serious equine conditions such as founder, laminitis and colic may be connected to the feeding of processed grains and use of corn oil as an energy source. This is particularly problematic for performance and work horses when grass and hay cannot always supply all the energy the horses need for work. Since the digestive system cannot handle the bulk needed, extra nutrients are fed as concentrates.
Fats in the form of vegetable oils or marine oil (fatty acids like EPA/DHA) are a useful means of obtaining these extra calories since they can be broken down to simple, easily utilized molecules. The questions remains, what type of fats are most beneficial to the health of your equine athlete?
Each horse has individual genetic and environmental factors that influence the essential fatty acid requirements. A horse's age, growth rate, height and shape all make a difference. How well the horse digests its food, how efficiently it absorbs nutrients, and the amount and kind of bacteria in its colon that digests the roughage, also play a role. Each horse's needs depend on whether it is stabled or kept in a field, whether it is clipped or not, in addition to the humidity and temperature levels. It has also been proven that males generally have higher energetic requirement than non-breeding females.
The recommended percentage of fat concentrates can vary depending on the amount of work done and can range anywhere from 15 to 45% in the use of concentrates. The use of supplemental vegetable oil (corn oil) in horses' diets has increased. Initially it was a common practice in the endurance discipline, but now it is being recommended for many performance horses.
Common equine foods contain only 2 to 4% fat. Performance foods are fortified with fat (usually vegetable oil) and contain anywhere from 6 to 14% fat in the feed. This means the horses are obtaining anywhere from about 9 to 30% digestible energy.
Unfortunately, this practice has contributed to the horses becoming intoxicated with omega-6 fatty acids. The delicate balance between omega-6 and omega-3 is disrupted. While corn oil is a good source of energy, it unfortunately exacerbates an already unhealthy ratio between omega-6 and omega-3. Since corn has a very high LA to LNA ratio, it suppresses omega-3 metabolism. In most commercial feeds, the omega-6 to omega-3 ratio is around 25 to 1, while for most mammals it should probably be closer to 3 to 1.
Since both of these fatty acid families are competing for the same enzyme, an overabundance of one fatty acid may inhibit the formation of the other family. The omega-6 family accounts for the production of several inflammatory agents, while the omega-3 family (particularly EPA and DHA) provide the bases for anti-inflammatory agents. Chronically elevated levels of omega-6 are connected to arthritic inflammations, thrombosis, bronchoconstriction, skin disorders and even tumor growth.
The horse's ability to adapt to a greater percentage of fat in the diet seems to be good, but increased levels of fat should be implemented gradually. Horses have been shown to be able to digest and use up as much as 20% or more of the diet (by weight) as oil when well adapted. You should use two to three weeks of gradual introduction to any oil used as an energy supplement.
It is important to note most commercial vegetable oils are molecularly modified through the refining process and they may also be diluted. They are not able to guarantee the natural lipid energy density of 9 Kcal/gram of lipid. Clinical grade fish oil on the other hand, provides a wide range of health-related benefits and represents the most caloric dense natural source of energy providing 9 Kcal/gram or 270 Kcal/ounce of lipid as an energetic source.