Fish Oil and Omega-3

March 5, 2019

Why fish oil is a superior source of Omega-3’s

By Jennifer Weir

The advantages of using fat in the horse diet has been spotlighted in recent years. Most notably are the essential fatty acids, called essential because they are necessary for life. These are the omega fatty acids. Omega-3 supplementation has many benefits in the horse and has been the basis of many products on the market today. Research has shown it to reduce inflammation, aid in digestion, boost the immune system, diminish airway inflammation, and aid in heart health. Positive effects on fertility and fetal development have also been shown. However, these fatty acids cannot be manufactured in the body and must be obtained from the diet. Horses that graze on fresh, green grass all day are getting plenty omega-3’s in their diet, however a lot of our horses today do not have access to quality pasture. Hay has diminished omega-3’s available due to the drying process. Are all sources of omega-3 fatty acids the same? How do you know which source of omega-3’s are the best?

The majority of equine supplements use flaxseed (a plant source) or fish oil as their source of dietary omega-3’s. Flaxseed contains the omega-3: alpha-linolenic acid (ALA). In the body, ALA must be converted to eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA). Research from Colorado State University shows horses can convert ALA to EPA and DHA, but it is not efficient. Some thoughts are that only 8-10% of EPA and 4% of DHA are converted. Flaxseed also needs to be ground in order for the horse to utilize the ALA contained in it. Ground flaxseed starts to oxidize once oxygen hits it, rendering it useless after a very short time. While fish oil can be oxidized quickly as well, keeping it in the oil form helps delay oxidation.

Fish oil contains the omega-3’s: eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA). Research  has shown these fatty acids to have many benefits including reducing joint inflammation and increasing stamina in performance horses.  Fish oil does not have to be converted in the horse’s body to be useful for its anti-inflammatory properties. This point alone makes it superior to flaxseed. In the human, EPA has been shown to block the pro-inflammatory omega 6’s and it is thought to be the same in horses. European research has shown that supplementing omega 3’s from marine sources (like fish oil) reduced chronic airway inflammation. It affects the horse all the way down to the cellular level by reducing inflammatory immune responses.

While most horses get plenty of omega-3 fatty acids in their diet when they are out grazing fresh green grass, we have to be honest about the man-made situation most of our equine athletes live in today. To help them stay in the best condition and health to perform at the top of their game, supplementing with omega-3 fatty acids could well be giving them the best chance yet.  Knowing the best source of omega-3’s to feed is paramount to keeping these equine athletes a step ahead of the rest. While research into essential fatty acids is ongoing and much needs to be learned, the studies we do have available are remarkable. Marine sources like fish oil have come out on top every time when compared to plant sources of omega-3 fatty acids. Fish oil has proven to be superior to the rest.

Jennifer Wier, MS
Nutritional Consultant
O3 Animal Health, LLC


That was a phenomenal article Jonathan. Thank you for writing it and sharing it. Ruffian was my second love (after Man O' War) and I simply cannot stop the tears from falling every time I read about this magnificent black beauty.

Maria Schlemmer Ackerman View testimonials