If you have recently walked through the equine supplement aisle of your local feed store, chances are there are multiple omega-3 (O3)-rich oils on the shelves. These supplements have been gaining popularity among horse owners and there is valid scientific reasoning behind this.

Research supports the supplementation of omega-3 fatty acids, as there is evidence to suggest that supplementation could help to manage many chronic conditions such as osteoarthritis, laminitis, heaves, and equine metabolic syndrome. Research has also reported that supplementation may help to increase the longevity of performance horses. In addition to those benefits, O3s have also been shown to improve the health of the horse’s hair coat.

What do Omega-3s and 6s do?

Omega-3s are an anti-inflammatory fatty acid. They are required for basic physiological functions and are key components of many tissues and organs. Omega-6s (O6s) are often portrayed as the “bad guy” because they are pro-inflammatory. However, both O3s and O6s are essential in the equine diet. Omega-6s are important components of inflammatory pathways which are crucial to the body maintaining homeostasis.

The ratio of O3s to O6s is key because you want to avoid having an exacerbated level of omega-6s in the diet to ensure you do not have exaggerated inflammatory responses. When inflammation occurs in excess, it contributes to an array of performance-limiting issues. However, when you do not have the necessary inflammation to help the body return to homeostasis, there can also be complications that limit performance. Therefore, balance is crucial.

The focus on omega-3 supplementation is likely due to equine diets often oversupplying omega-6s which are pro-inflammatory. Currently, we do not know the ideal ratio of O3:O6s, but forages and pastures are higher in O3s. Based on this it is hypothesized that the omega-3 content of the diet should exceed the omega-6 content. Further research is required to elucidate the ideal ratio for supplementation.

Why Does Type of O3 Matter?

Not all omega-3s are equally effective when supplemented. If you have been paying attention to the various supplements on the market, you will likely be familiar with the terms EPA (eicosapentaenoic acid) and DHA (docohexaenoic acid).

The metabolic pathway for O3s and O6s both begin with a parent molecule. For the omega-6s this is linoleic acid (LA) and for the omega-3s this is alpha-linoleic acid (ALA). For these molecules to be altered into fatty acids that are further down the metabolic pathway, the enzyme delta-6-desaturase is required. This is a liver enzyme that elongates the parent molecule before the horse can synthesize DHA, which is the end goal.

Now, since both the O3 and O6 pathways use the same enzyme, it is rate-limiting. There is only so much of that enzyme available to use. Therefore, if we supplement our horses with omega-3s that are further down the pathway (e.g., EPA and DHA) it can improve their ability to use those fatty acids and increase the beneficial outcomes.

When to Supplement & Choosing the Correct Supplement for Your Horse

Omega-3 rich oils are supplemented in equine diets for their anti-inflammatory properties as well as their caloric value. These oils are calorically dense, and if they are introduced to the diet slowly can make fantastic energy sources. This is a great tactic to increase the digestible energy content of a ration without increasing the grain products.

What many horse owners do not know is that pasture is a great source of omega-3s; after all, this is what the horse has evolved to consume. Unfortunately, in Canada, providing pasture year-round is not feasible and many farms do not have the land resources to have horses housed on pasture all summer. A second issue is that when grains are incorporated into the diet they provide a significant amount of omega-6s. Therefore, supplementation of omega-3s to optimize the O3-to-O6 ratio is often recommended.

When looking for an omega-3 supplement, it is important that you are choosing one that provides the correct omega-3s. Not only do you want DHA, but you also want omega-3s that can readily be converted (skipping the rate-limiting step) such as EPA & SDA (stearidonic acid).

Fish oil is a well recognized source of both SDA and DHA; however, it can be problematic when supplemented to horses as they are herbivores and the palatability of fish oil is low. Plant oils vary greatly in omega-3 fatty acid content. For example, corn oil and soybean oil are both much higher in omega-6s than omega-3s, whereas, flax oil and camelina oil are higher in omega-3s.

What about some of the commercial oils that are marketed to have EPA and DHA? Research does illustrate clear benefits to DHA supplementation, so in certain situations spending the extra money on these is likely beneficial. However, every situation is unique and having your horse’s diet evaluated by an equine nutritionist can help you decide.

To conclude, when deciding on a supplement, what really matters is your goal. Are you trying to level out a high omega-6 ratio? Are you trying to increase caloric content? Are you trying to combat chronic inflammation? Each of these situations will have a different ideal supplement.

If you have any specific questions about your horse’s diet, contact a qualified equine nutritionist!