Proper Amounts of Feeding Omega 3 Fatty Acid for Horses

You brought up the benefit of omega 3’s…If it is already in their feed, is it necessary to also have it in your fat supplement? How much is beneficial? There are studies that claim it can negatively affect their immune system if they are given too much, so how much is too much? Thank you. K

Dear K,

Since hay contains very little fat, when you say there are omega-3s already in your horse’s feed, you must mean in his fortified grain. And I assume the brand of grain you are feeding specifically says omega-3 on the label, because that is not required to be listed. Generally cereal grains are higher in the omega-6 fatty acids, which is why some horse owners are interested in giving their horses omega-3 to restore the balance or ratio between the two. Horses (and all animals) need both kinds for their bodies to function well.

The current theory is that omega-3 fatty acids are anti-inflammatory and omega-6 fatty acids are pro-inflammatory. This downgrading of the body’s natural immune response is probably where you got the idea that omega-3s “negatively affect their immune system.” For horses with conditions like allergic skin disease, autoimmune disease, recurrent airway obstruction (heaves) and others, that’s exactly what horse owners are hoping the omega-3s will do! For other conditions, like fertility issues in stallions, EIPH and laminitis, the ability of omega-3s to alter cell membranes and red blood cells may be how they exert their beneficial effects.

If your horse’s primary source of forage is fresh green grass, then he may already be getting enough omega-3s to produce a shiny coat, healthy hooves and even support his joints. But if he mainly eats hay for roughage, then here are some guidelines.

A study by O’Connor and others entitled “Dietary fish oil supplementation affects serum fatty acid concentrations in horses” 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. To put this into 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.

Besides fish oil, other good sources of omega-3s include flax seed and chia seed.