The benefits of omega-3 fatty acids for horses are believed to be numerous: decreased inflammation in various tissues, increased immune response, maintenance of healthy membranes, and an upsurge in sperm production, to name just a few.

Flaxseed and flaxseed oil have been fed to horses for decades, primarily to improve coat condition of sales or show horses. Both flaxseed and flaxseed oil are rich sources of the essential fatty acid alpha-linolenic acid (ALA), which is thought to convert to the omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA).

For many years, the conversion of ALA to EPA and DHA was believed to be efficient. Now, however, a summary of omega-3 research by the International Society for the Study of Fatty Acids and Lipids (ISSFAL) has questioned the ability of ALA to be changed in the body.

According to the summary, "conversion of ALA to EPA is very low, and to DHA is even less–essentially negligible. These very low conversion rates mean that ALA cannot meet the body's need for DHA."

Tom Brenna, MS, PhD, professor of nutritional sciences at Cornell University and chairman of the ISSFAL committee that assembled the summary, said, "Each type of omega-3 has distinct functional properties. Seafood/algal omega-3s, also known as long-chain omega-3s, are more potent than terrestrial plant sources of omega-3s and boast certain functions that terrestrial plant-based omega-3s simply cannot perform."

The summary reported that DHA levels in the body were raised most markedly by consuming "preformed" DHA, such as that found in marine-derived oils.

Although the aforementioned summary included studies involving primarily humans, what impact does this research have on supplementation of omega-3 fatty acids to horses? Foremost, horsemen might look beyond flaxseed for an effective omega-3 supplement. One alternative is oil derived from certain cold-water fish. Fish oil is a direct source of EPA and DHA, so the question of whether or not ALA can efficiently be converted to EPA and DHA becomes obsolete.

Raw fish oils are typically not palatable to horses. Recent advances in deodorization and flavoring technology have made fish oils acceptable to most horses.

In two-choice preference trials with Thoroughbreds, horses showed no significant preference for either fish oil or soybean oil after four days of side-by-side supplementation. Similar rates of grain intake were noted, so addition of the fish oil had little effect on consumption of meals.

The ability of horses to efficiently convert ALA to EPA and DHA is not known, and thus requires more research. What is known, however, is that oil obtained from certain fish provides horses with EPA and DHA, thereby foregoing the need for conversion at all.

Kentucky Equine Research (KER) has written extensively about the advantages of omega-3 fatty acids in the diets of horses. The KER Web site contains a searchable library that includes numerous documents related to this topic. Of particular interest is an Equine Review article.

Article courtesy of Kentucky Equine Research.