Importance of Omega 3 and 6 Fatty Acids for Horses

Updated April 10, 2024

Omega 3 and 6 fatty acids are essential to your horse’s diet because they support everything from individual cellular health to overall well-being. We’ll help you understand where omegas can be sourced from, their effects on the horse’s body, and how feeding a diet with the right ratio of omega 3 to 6 can impact your horse’s health.

Fats and Fatty Acids

Fats and oils are typically given to horses as a source of calories to support healthy weight gain, improve coat condition and shine, and fuel performance. A source of “cool energy,” research has shown that feeding fats to horses may reduce excitability and reactivity when compared to feeding starch and sugar concentrate meals.

Fats also carry fat-soluble vitamins (A, D, E, and K) and provide essential fatty acids (EFAs). When nutrients are referred to as “essential,” this means they must be consumed through the diet. Omegas 3 and 6 are considered EFAs as horse’s lack the enzymes necessary to synthesize them from scratch.

The composition of fatty acids is important when it comes to your horse’s nutrition. Oils and fats may contain the same amount of caloric energy per gram, but they do not have the same impacts on your horse’s body. A fat source rich in omega 3 fatty acids can provide benefits across many body systems.

Benefits of Omega 3 for Horses

Omega fatty acids are named for their chemical structure but valued for their many health benefits. Research in horses has demonstrated positive effects of omega 3 fatty acids, including:

• Supports skin and coat health
• Promotes a normal immune and inflammatory response
• Helps maintain healthy cartilage and connective tissue
• Supports proper digestion
• Promotes normal metabolic function
• Helps with healthy hoof growth
• May improve reproductive health in stallions

A consensus statement on inflammatory airway disease (heaves or RAO) in horses, published by the American College of Veterinary Internal Medicine, mentions the benefit of combining omega 3 fatty acids with other management changes to support respiratory health [3]. A number of studies also support the value of omega 3 supplementation for horses with seasonal allergies and respiratory inflammation [5].

Sources of Omega 3 Fatty Acids

Omegas may be derived from:

• Fish sources: Consists of Eicosapentaenoic acid (EPA) and Docohexaenoic acid (DHA), the body is directly able to use these forms of omega 3s. 
  • Fish oil and algae are naturally high in EPA and DHA, making them some of the best sources of omega 3 fatty acids. 
• Plant sources: Has alpha-linolenic acid (ALA). Once ingested, ALA is converted to EPA and DHA so it can be used by the body. 
  • Fresh grass, flaxseed, and chia seed are great sources of omega 3 fatty acids. 

Ratio of Omega 3 to Omega 6 for Horses 

Though your horse needs both omega 3 and 6, maintaining the correct balance between the two is critical. Omega 3 fatty acids are thought to support anti-inflammatory responses in your horse’s body, while omega 6s support pro-inflammatory responses.  

While occasional inflammation plays an important role in your horse’s overall health, a chronic state of inflammation can be problematic, causing stress in your horse at the cellular level, increasing wear and tear on joints, and more. That’s why experts recommend that horses get 2 – 4x more omega 3 than omega 6 in the diet. 

Unfortunately, the typical diet of a modern horse can make achieving that balance challenging. 

An Unnatural Balance

Your horse was built to thrive on fresh grass, which naturally contains more omega 3 fatty acids than omega 6. Because acres of fresh pasture can be hard to come by (and some easy keepers and other horses cannot have unlimited access to grazing), most horses' diets are primarily composed of hay and grain.  

This presents a challenge because, by the time it’s cut, dried, baled, and stored, hay contains virtually no omega 3s. Hay is typically around 2% fat and most of that is omega 6 (100 grams for every 11 lbs of hay).  

Further, fortified grains are typically high in omega 6s. So, a combination of low-to-no grass pasture and feeding grain can lead to an imbalance in the omega 3 to 6 ratio, setting your horse up for a chronic state of inflammation. 

Finding the Right Ratio 

Use this table below to help you understand if you’re feeding your horse a diet with the right balance of omegas. Remember, you’ll need to consider every feed source and the amount being fed when calculating the overall omega 3 to 6 ratio in your horse’s diet.

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Feeding Your Horse an Omega 3 Supplement 

Adding a daily supplement with beneficial omega 3 fatty acids is a smart way to improve upon the important 3:6 ratio and support your horse’s overall well-being. An omega 3 supplement (potentially with vitamin E as well) is an especially a good option for horses without access to fresh grass.  

There are many high-quality, palatable supplements derived from flaxseed, fish oil, camelina oil, and other sources to choose from. Some commercial horse feeds are also formulated with omega 3 fatty acids to better balance the ratio.  

Frequently Asked Questions About Omegas for Horses 

How much omega 3 does a horse need per day? 

There is no established feeding requirement for fatty acids in horses, however, it is suggested in the Nutrient Requirements for Horses that the diet has at least 0.5% linolic acid (an omega 6 fatty acid). This simply means that a required amount of omega 3 has not been quantified yet.  

However, a study on serum fatty acid concentration [4] showed that 63 days of supplementing fish oil at the rate of 324mg/kg of body weight was enough to alter the fatty acid profile and blood lipid properties of horses receiving regular exercise. In practical terms: 

• 324mg/kg body weight X 500kg horse = 162 grams (or about 7 ounces) of fish oil. 
• Fish oil is 10.8% EPA and 8% DHA, so the amount above would provide 17.5 grams EPA and 13 grams DHA. 

Can a horse get too much omega 3? 

Specific studies in horses looking at the effects of omega 3s have not demonstrated any adverse effects. Additionally, flaxseed and other sources of omega 3 fatty acids have a long history of safe use in the horse. However, when introducing any new feed to your horse’s diet, it is best to begin with a small amount and increase gradually to give your horse’s digestive tract time to adapt. 

Key Takeaways 

1. Your horse needs both omega 3s and omega 6s in his diet. 
2. Because omega 3s support anti-inflammatory reactions, while omega 6s support pro-inflammatory reactions, you want four times more 3s as 6s in your horse’s diet. 
3. Hay contains almost no omega 3s, and grains are much higher in omega 6s, so if your horse is getting anything other than pasture, you should consider adding a supplement rich in omega 3s. 

Evidence-Based References 

1. Holland, J. L., Kronfeld, D. S., & Meacham, T. N. (1996). Behavior of horses is affected by soy lecithin and corn oil in the diet. Journal of Animal Science, 74(6), 1252. https://doi.org/10.2527/1996.7461252x  
2. Holland, J. L., Kronfeld, D. S., Hoffman, R. M., Greiwe-Crandell, K. M., Boyd, T. L., Cooper, W. L., & Harries, P. (1996). Weaning stress is affected by nutrition and weaning methods. Pferdeheilkunde, 12(3), 257–260. https://doi.org/10.21836/pem19960319  
3. Couëtil, L. L., Cardwell, J. M., Gerber, V., Lavoie, J., Léguillette, R., & Richard, É. (2016). Inflammatory Airway Disease of Horses—Revised Consensus Statement. Journal of Veterinary Internal Medicine, 30(2), 503–515. https://doi.org/10.1111/jvim.13824  
4. C. I. O'Connor, L. M. Lawrence, S. H. Hayes, Dietary fish oil supplementation affects serum fatty acid concentrations in horses, Journal of Animal Science, Volume 85, Issue 9, September 2007, Pages 2183–2189, https://doi.org/10.2527/jas.2006-528 
5. Nogradi, N., Couetil, L.L., Messick, J., Stochelski, M.A. and Burgess, J.R. (2015), Omega-3 Fatty Acid Supplementation Provides an Additional Benefit to a Low-Dust Diet in the Management of Horses with Chronic Lower Airway Inflammatory Disease. J Vet Intern Med, 29: 299-306. https://doi.org/10.1111/jvim.12488  

For more research studies on fish oil, DHA, EPA, flaxseed and other ingredients, head to our Supplement Ingredients Backed by Research.