Magic Omegas

Fresh green grass—a horse's natural diet—is very low in fat at only 4% to 6%. But horses do require a dietary intake of omega-3 and omega-6 fats because the body can't manufacture them.

You've probably heard some talk about omega-3 and omega-6 fats contributing to human heart health. Your horse needs these essential fats in correct amounts too, but first let's take a brief look at fat requirements in general.

Dietary Requirement for Fat
The horse has no actual dietary requirement for fat per se. A horse's natural diet-grass and other plants-is very low in fat. It ranges from 4% to 6% fat, versus around 30% in a "moderate" human diet.

The reason there's no dietary requirement set for fat-as there is for protein, for example-is that the horse can manufacture fats very easily from carbohydrates or amino acids. So can humans. This is how excess calories from any source are converted into fat for storage.

However, horses and people do require dietary intake of two very specific kinds of fat called omega-3 and omega-6 fatty acids. These are called essential fatty acids because it's essential that they be present in the diet since the body can't manufacture them internally. They serve very important, and very different, functions.

Inflammatory Response
The inflammatory response is very important to the smooth functioning of a healthy immune system and defense against diseases. The omega-6 fatty acids are important in generating a vigorous immune response, while the omega-3 fatty acids work to keep the response in check and also protect the immune system from damage.

For example, endotoxemia is a condition that results when bacterial toxins get into the horse's bloodstream. This typically causes a body-wide severe inflammatory response. Several studies have shown that feeding a source of omega-3 fats can modify the severity of that reaction. Other conditions, such as arthritis and allergies, also have an inflammatory component.

Anti-Inflammatory Effects
Omega-3 fat is present in plant material as alpha-linolenic acid. Once inside the body, this undergoes conversion to eicosapentaenoic acid (EPA) and then to docosahexaenoic acid (DHA).

When a human or other carnivore/omnivore eats meat or fish, they consume omega-3 fatty acids in the form of EPA and DHA directly, without conversion.

DHA then is further converted to an anti-inflammatory prostaglandin (a signaling molecule that tones down inflammation and blood clotting) and other cytokines (signaling molecules) that are cousins to inflammatory cytokines but have much weaker effects.

The omega-6 fat in plants is alpha-linoleic or gamma-linoleic acid. The alpha-linoleic acid in plant foods is converted to gamma-linoleic in the body and from there to arachidonic acid, which gives rise to cytokines that are involved in inflammation.