Omega-3 Fatty Acid and Horse Nutrition

Some of the most frequently asked omega-3 questions include… “Do I feed omega-3 to my horse? How much omega-3 do I feed? Is there omega-3 in your feed? What is the omega-6/omega-3 ratio in your feed?”


  1. Forage fed only horses (grazing or hay) consume less than 3% fat
  2. Omega-3 (linolenic) requirement has NOT been established for horses
  3. Omega-6/omega-3 ratio for horses is NOT known

It is not uncommon for humans to ascribe their nutritional needs to their horses or other companion animals. Since the Dietary Supplement Health and Education Act of 1994 there has been a surge in over-the-counter supplements including omega-3 supplements. Science has clearly demonstrated the importance of food sources containing omega-3 fatty acids DHA/EPA for humans … but, does that understanding apply to horses?

Keep in mind DHA/EPA are the forms through human research that have demonstrated health benefits and the primary source of DHA is cold water fish. The omega-3 plant form consumed by horses is NOT DHA & EPA, but the plant form ALA (alpha-linolenic acid). Generally, ALA is poorly converted to the beneficial forms DHA & EPA. However, one would surmise that although poor conversion, there is adequate conversion for the horse’s low-fat base forage diet. The forage of grazing horses is less than 3% fat. Horses are herbivores, humans are omnivores (consumes animal & plant sources) and humans consume a much higher dietary fat diet compared to horses.

Omega-3 and omega-6 fatty acids are considered essential for animals but the omega-3 (linolenic) requirement has NOT been established for horses and for omega-6 (linoleic) only a “suggested” level based on total feed intake, and that can be easily accomplished via feeding a balance formula with modest fat. Today, horse diets contain higher fat via rice bran and vegetable oils as a fuel alternative to grains such as corn and barley; clearly omega-3 requirements may be different for a horse that is only forage fed compared to one that is working at heavy to very heavy levels and is consuming a high fat balance concentrate.

So, if the actual daily omega-3 requirement is not known, then the omega-6/omega-3 ratio for horses is also NOT known. For humans, the ratio is 1:1 to 4:1 (omega 6 to omega 3). This human omega-6/omega-3 ratio can NOT be applied to horses or any other herbivore animal. By the way, the ratio is omega-6 to 0mega-3 NOT 3 to 6. Often the ratio is incorrectly referenced as the inverse.

Granted, essential fatty acids studies with horses are limited and mixed. However, there are favorable studies with omega-3 rich diets including nursing foals via mare’s milk received omega-3 fatty acids and qualitative and quantitative improvement in stallion’s semen evaluation. Because of the limited studies with very few horses one needs to be cautious with conclusions and materials that imply or suggest direct health benefits, particularly those that are anecdotal.

Now, does it make biological sense that linoleic (omega 6) and linolenic (omega 3) fatty acids are essential fatty acids for the horse. YES. But, the low fat, high fiber levels of their natural food sources and a gut system that is forage driven does NOT permit a leap to conclusions equivalent to humans. Human diets are much higher fat and humans have a much longer life-span; …longer life span, more opportunity for health and diseases to surface as challenges. One other point, horses have a different gut system; one that is much longer and different in compartment numbers and capacity. Those gut differences translate to a diet that is different in composition of fiber, protein, fat and primary energy sources. Dog’s consume higher fat diets but the omega-3 research with dogs suggest the practical feeding benefits remain inconclusive.

Omega-6 fatty acids have an inflammatory effect important for healing. Omega-3 fatty acids have an anti-inflammatory effect and important to suppress/moderate the inflammatory effect. Yes, an excess of one group of omega fatty acids can interfere with the metabolism of the other but that information was derived from human diets that were high fat, low fiber and NOT with forage base, high fiber diets of herbivores. The interference is because the omega 3 and 6 fatty acids compete for the same enzymes for metabolic conversion.

Is it important to consider the type of fat fed to horses? YES. Then, what are the best plant sources of the omega-3 ALA? … flaxseed oil and whole ground flaxseed meal. Canola oil does contain ALA but in modest amounts. Integrity balance formulas contain whole ground flaxseed meal & canola oil; the omega-6 to omega-3 ratio for Integrity Adult/Senior with molasses is 3:1 and for Adult/Senior no molasses, also 3:1.

So, when could omega-6 & 3 ratios be an issue? The following are when the diet sources of fat may need to be considered:

  • When feeding inadequate forage with high fat supplemental feeds
  • Feeding a total diet at high fat levels (>10%); note, that’s total diet which includes forage, concentrates, added fat, supplements, etc.
  • Feeding a concentrate that is high in grains; that is, grains listed in the beginning of the feed label ingredient list
  • Feeding more than 10 lbs. of a concentrate that’s >12% fat,
  • A high fat diet that is void of omega-3 ALA fat sources whole ground flaxseed meal, flaxseed oil and/or canola oil

One final point of interest … what/which fat is better for skin and hair coat? Early foundation studies on omega fatty acids demonstrated that when feeding omega-6, the symptoms of skin conditions, loss of hair & kidney damage disappear. Feed omega-3, the skin symptoms remained, but the animal grew better. Corn, soy, and sunflower oils are good sources of omega-6 fatty acids.