Omega 3 fatty acids have made the headlines numerous times over the past year. Often touted for their many health benefits to humans, they are also appear to be beneficial to your horse.
The most common omega-3 in the equine diet is alpha-linolenic acid.
Omega-3's, like omega-6's, have numerous important functions throughout the body. They
- are an essential component of many body structures
- play an important role in immune function
- are an important part of the phospholipid bilayer of cell membranes
- play an important role in vision
They can also be metabolized to make a hormone-like substance called an eicosanoid (more on those later!).
Sources of Omega-3 fatty acids
There is only one naturally occurring source of omega 3 fatty acids in the equine diet: fresh grass. However, flax seed which is commonly supplemented to horses, is also very high in omega-3's. 53% of the fatty acids found in flax seed are alpha-linolenic acid.
However, there are other sources of omega 3 fatty acids in the equine diet...these other sources just do not contain as much omega-3 as fresh grass and flax seed.
11% of the fatty acids in canola oil are alpha-linolenic acid. Soybean oil comes in at 6% alpha-linolenic acid.
Eicosanoids
Eicosanoids are chemicals that regulate vital body functions, such as blood pressure, blood clotting, immune response, and inflammation response. They are sometimes referred to as "local hormones". They act like hormones on the body, but unlike "regular" hormones such as insulin, they are used where they are produced and not transported in the blood.
An eicosanoid produced from an omega-3 has a vastly different effect on the body than one produced from an omega-6, which is why it is essential that both omega-3's and omega-6's are present in the equine diet.
In general, the eicosanoids that are created from omega 3 fatty acids are going to produce less of an inflammatory response in the body than one from an omega-6. They are also going to produce less of a blood clotting response.
This lessened response is the reason that omega-3 supplementation is often recommended for horses suffering from arthritis, allergies, sweet itch, and other ailments that involve inflammation responses.
Eicosanoids produced from omega-3's are converted to eicosapentaenoic acid (EPA) and then decosahexaenoic acid (DHA). After that, DHA is converted to a group of substances referred to as the prostaglanding PG3 series. It is this conversion that is the reason for many of the benefits of omega-3's.
A recent study done on ponies predisposed to sweet itch found that dietary supplementation with feeds high in omega-3's (in this case flax) reduced the response to the fly that causes sweet itch.