Omega-3 Vs Omega-6 Fatty Acids, Getting The Ratio Right

We often talk about increasing the omega-3 : omega-6 fatty acid ratio in a horse’s diet, but what does this actually mean, and why should the ratio be in favour of omega-3s.

Omega-3 and omega-6 fatty acids are essential fatty acids meaning they cannot be made by the horse and must be supplied in the ration. Each fatty acid is necessary for the production and distribution of prostaglandins, however the prostaglandins from omega-3 and omega-6 fatty acids have different effects on inflammation processes in the body. In simple terms, we consider omega-3 fatty acids to be anti-inflammatory, and omega-6s to be pro-inflammatory. This is because the inflammatory response from cytokines and prostaglandins that originate from omega-3 fatty acids is moderate compared to the response from cytokines and prostaglandins derived from omega-6s. Therefore, the ratio of these fatty acids must be balanced within the body for both to be effective.

The optimal ratio of omega-3s to omega-6s has not yet been established for horses, but it is thought that a ratio of 2 to 4:1 could be optimal.

For horses in work, particularly intense exercise, omega-3 fatty acids help to reduce excessive inflammation post exercise. Increasing the intake of omega-3s is also supportive of any issue that stems from the inflammatory pathway. Allergic reactivity, joint inflammation, respiratory disorders such as exercise induced pulmonary haemorrhage (bleeders), equine glandular gastric disease, recurrent exertional rhabdomyolysis (tying up), and equine asthma are all examples of disorders that are linked to the inflammatory pathway. So, increasing the anti-inflammatory omega-3s in the ration can help to reduce the severity of these issues. Alternatively, a ration high in omega-6s could increase severity.

Forage has a higher ratio of omega-3 fatty acids to omega-6 fatty acids. So, horses on a fibre-based ration, such as forage and super fibre cubes, are likely to already have this correct balance in favour of omega-3s. However, cereals are higher in omega-6 fatty acids, meaning all horses that consume a ration high in cereals would benefit from additional omega 3-fatty acid supplementation to shift the ratio back in favour of omega-3s.

Horses are often fed supplemental sources of fat to add additional calories to their rations. Corn oil, safflower oil, canola oil, and sunflower oil are all rich in omega-6 fatty acids. Feeding one or more of these, especially in combination with a high-grain diet, may supply a horse with a surplus of omega-6 fatty acids, creating a balance of omega-3 to omega-6 fatty acids that may be inappropriate. Such diets may not be as beneficial as one abundant in omega-3 fatty acids.