Question
I would like to start my overweight, insulin-resistant 23-year-old draft gelding on an omega-3 supplement. He is fed soaked hay and a ration balancer, and he wears a muzzle when he is allowed access to pasture. How can I best supplement with omega-3s? Other thoughts?
Answer
Research indicates that supplementation with polyunsaturated long-chain omega-3 fatty acids can be beneficial for horses faced with metabolic challenges, including positively altering insulin response.* Aside from the potential metabolic advantages, supplementation with long-chain omega-3s may be useful in reducing joint inflammation associated with age and a history of hard work. Specifically, the long-chain omega-3 fatty acids known as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) should be fed.
Choosing the best source of long-chain omega-3 fatty acids is important, as not all supplements are processed by the horse efficiently.
Kentucky Equine Research compared flax oil and EO-3, a marine-derived oil rich in EPA and DHA. This research demonstrated that daily intake of EPA and DHA from EO-3 significantly increased levels of EPA and DHA in red blood cell membranes—a common method to gauge body-wide levels of fatty acids—and that a similar amount of omega-3 from flax oil did not. Researchers at Colorado State University and University of Florida reported similar findings. Horses cannot efficiently convert the omega-3s found in flax oil into EPA and DHA. Therefore, a marine-derived source of EPA and DHA, such as EO-3, is needed to significantly influence the uptake of polyunsaturated long-chain omega-3s into cell membranes. Read that research here.
Although you mentioned that your horse is overweight, you didn’t indicate how much hay or what type of hay he is offered. If you’re trying to slim down your gelding, provide about 1.5% of his body weight daily in forage. Here’s the math: 2,000 lb (910 kg) body weight x 0.015% of body weight = 30 lb (13.5 kg) of forage daily. Use the same simple formula with your horse’s target weight.
His hay can then be offered in ways that encourage slow intake, such as specially designed slow-feed haynets. The hay should be clean without any visible mold, dust, weeds, or other impurities. A grass hay would be most appropriate for him. Soaking will help remove soluble carbohydrates from hay. Soak a minimum of 30 minutes in hot water or 60 minutes in cold water. Soaking leaches out other soluble nutrients, so it is important to ensure that the total diet is balanced and provides all essential nutrients. You’re likely already accomplishing this by feeding a balancer pellet. Because of his weight, you’ll want to double-check that you’re feeding enough of the balancer pellet. Refer to the manufacturer’s recommendations, which can be found on the feed bag or tag.
Some horses with metabolic problems cannot graze at all due to the risk of laminitis. Even though you don’t mention this, your caution in using a grazing muzzle is a wise management decision.
If your horse is sound, you could ask him to do light work several days each week. This may be in the form of riding, driving, or another activity of sufficient intensity that raises his heart rate. In addition to fighting obesity, exercise can help keep advanced metabolic disease at bay.
*Elzinga, S.E., A. Betancourt, J.C. Stewart, M.H. Altman, V.D. Barker, M. Mulholland, S. Bailey, K.M. Brennan, and A.A. Adams. 2019. Effect of docosahexaenoic acid-rich microalgae supplementation on metabolic and inflammatory parameters in horses with equine metabolic syndrome. Journal of Equine Veterinary Science 83. doi.org/10.1016/j.jevs.2019.102811
