EPA and DHA Rule Omega-3 Support for the Horse

Several O3 Animal Health patented products contain fish oil for the sole purpose of providing your horse with direct sources of EPA and DHA. Why is this so important? While consuming fish oil may not be a natural part of a horse’s diet, the fats contained in fish oil, have vital health benefits for the horse.

While the plant-based forms of ALA, such as flax oil, camelina oil, soybean oil and others, that are commonly added to horse diets mirror what would be in the horse’s natural diet there is a problem.  The conversion of ALA to Stearidonic acid from plant sources is rate limited. Fish oil is the ONLY direct source of EPA and DHA for the horse.

By feeding O3 animal health products that contain fish oil, you are supporting your horse’s natural ability to regulate inflammation while giving yourself the peace of mind that your horse is not reliant on rate limited enzyme pathways and everything having to be optimal for success. The products are highly palatable, and most horses love the taste.

The pathways and conversion are complicated and more fully explained below.

In the world of omega-3 fatty acids, EPA and DHA are King and Queen. EPA is the final form of omega-3 fat prior to the creation of compounds such as Series 3 Prostaglandins, Thromboxanes, and Leukotrienes, and DHA is an important structural component of the brain and can be metabolized into special pro-resolving mediators. Series 3 prostaglandins have a modulating effect on the Series 2 prostaglandins that result from omega-6 fatty acid metabolism. 

Series 2 prostaglandins are necessary for swelling, inflammation, clotting and dilation which are all vital bodily functions. However, without the regulation from Series 3 prostaglandins, things can get out of hand, especially inflammation. This is how the omega-3 fatty acids get the reputation for being anti-inflammatory while omega-6 fatty acids are seen to be inflammatory. In reality omega-6 fatty acids are essential as is some level of inflammation, but unchecked inflammation is undesirable and can result in a number of negative health consequences. Too much omega-6 in the diet can feed into this but we will cover that later.

Under optimal conditions EPA and DHA are created through a series of steps that convert the fatty acid Linolenic acid (ALA). First the ALA is desaturated meaning that double bonds are removed from the long fatty acid chain creating Stearidonic acid. This requires the enzyme Delta-6-desaturase as well as biotin, magnesium, and zinc. The horse’s natural grass based diet provides quite large amounts of ALA each day. Today it is common to supplement diets with other sources of ALA because many horses are predominantly fed hay as their major source of forage and omega-3 fatty acids struggle to survive the hay curing process. These other sources of ALA include ground flax, flaxseed oil, soybean oil and camelina oil. Sometimes Stearidonic acid is supplemented which is found in hemp seed and Ahi oils.

Once Stearidonic acid is formed, it is converted to Eicosatetraenoic acid through elongation (making the fatty acid chain longer) and then further desaturated by removing more double bonds resulting in Eicosapentaenoic acid (EPA) which requires vitamin C, niacin and zinc. EPA can then be converted to DHA.

While the plant-based forms of ALA that are commonly added to horse diets mirror what would be in the horse’s natural diet there is a problem which is that the conversion of ALA to Stearidonic acid is rate limited. This means that the overall rate at which ALA is converted to EPA and DHA is dependent on that first step. This can be impacted by several things. For example, horses whose diets are deficient in zinc or horses that are making inadequate amounts of vitamin C, B6 and B12 will not be able to optimally convert ALA to Stearidonic acid. 

Perhaps the biggest thing to negatively impact this conversion step is the presence of high levels of omega-6 fatty acids in the diet.

It just so happens that the common dietary omega-6 fat Linoleic acid (LA) goes through its own conversion and metabolism within the body ultimately forming Arachidonic acid. And what is the enzyme needed for the first desaturase step of its conversion pathway? That’s right, the same Delta-6-desaturase that converts ALA to Stearidonic acid. And here’s the kicker, Delta-6-desaturase preferentially converts the omega-6 LA than the omega-3 ALA. 

This is not so much of an issue when consuming the horse’s natural diet of grass and other plants because such a diet is relatively low in omega-6 fatty acids. There is little competition for the desaturase enzyme. In fact, according to Equine Applied and Clinical Nutrition, the omega-3 to omega-6 ratio in grass-based diets is 1:0.3. However, when we switch to feeding hay this drops to 1:0.6 and if a concentrate containing 10 percent fat is fed this may invert to 1:7.8.

Now a problem potentially exists because the omega-6 LA will be preferentially converted to Arachidonic acid opening the door for the creation of inflammatory Series 2 Prostaglandins that may not be regulated because the body is unable to speed up the conversion of ALA to create the EPA needed to keep that inflammation in check. 

So, what is the solution? Quite simply to feed EPA and DHA directly and cut out the need for ALA conversion. The trick is that EPA and DHA do not exist in plants. The most common sources are fish oils, krill oil and algae. Oily fish such as salmon, herring, sardines and some tuna consume DHA and EPA containing algae and then concentrate the amounts in their fat. 

Many of the ways that we ask our horses to live and the actions we expect them to perform are outside of the realities within which they evolved. As a result, they are often faced with inflammatory insults while at the same time being fed diets that limit their natural ability to fight inflammation. 

The O3 Animal Health products that contain fish oil as one of our ingredients offers a valuable solution for providing EPA and DHA directly to your horse.