Flaxseed is quickly becoming a popular nutritional supplement for horses. But what exactly is flaxseed, and how does it benefit the horse? Here’s what you need to know.
What is flaxseed?
Flaxseed is produced by the flax plant, commonly grown in cool, northern climates. Flaxseed is also known as ‘flax’ or ‘linseed.’
What does flaxseed contain?
Flaxseed contains an average of 40% fat, but what differentiates flaxseeds from other high-fat foods is their fatty acid profile. Most of the fat in flaxseeds is in the form of two polyunsaturated fatty acids, linoleic acid (LA) and alpha-linolenic acid (ALA). Your horse requires both of these fatty acids to be healthy, but his body cannot produce them. Therefore, these fatty acids must be added to the diet. Consequently, by definition, LA and ALA are referred to as essential fatty acids (EFAs).
LA belongs to the omega-6 family of fatty acids and comprises 16% of flaxseed’s fatty acid content. Inside the horse’s cells, LA is converted to arachidonic acid, which promotes the formation of pro-inflammatory prostaglandins and eicosanoids.
ALA is one of several omega-3 fatty acids and comprises 58% of flaxseed’s fat content. It has the opposite effect of LA on inflammation: it reduces inflammation, leading to the formation of an anti-inflammatory omega-3 fatty acid known as docosahexaenoic acid (DHA).
These two fatty acids are both essential for your horse’s health, but they need to be in the proper proportion to each other.
The correct ALA to LA ratio
The ideal ratio of ALA to LA has yet to be formally established. It makes sense, however, to aim for the ratio that naturally exists in pasture grasses, as this is the ratio ‘wild’ horses would consume. Grasses’ average EFA level during warm growing seasons is 10 mg of ALA and 2.5 mg of LA per gram of dry matter. Therefore, this 4:1 ratio of ALA: LA is what horses would realistically consume in a ‘wild’ setting.
The requirement of these two fatty acids is also still being determined. However, unfortunately, hay no longer contains appreciable levels of EFAs, so supplementing these in the diet, unless your horse lives on excellent quality pasture year round, is likely necessary. To compound the issue, most commercial feeds have an inverted ratio with more LA than ALA, potentially damaging your horse’s health through excessive inflammation.
Benefits of flaxseeds
Flaxseeds have many health advantages.
Flaxseeds, as with any source of fat, aid in the absorption of fat-soluble vitamins A, D, E, and K, as well as other fat-soluble nutrients such as the increasingly popular turmeric (curcumin), Boswellia, and resveratrol.
Flaxseeds are also a great way to add protein to the diet, boosting the diet’s overall protein quality. When you offer a variety of protein sources, your horse’s body has a large, varied amino acid pool from which to choose for building and repairing tissues. This ultimately makes the repair and recovery process after exercise more efficient.
Flaxseeds are low in sugar and starch (2.6%), making them safe for horses with insulin resistance, Pituitary Pars Intermedia Dysfunction (Cushing’s Disease), and Polysaccharide Storage Myopathies. They are high in fibre (47%) with a large amount of pectin and mucilage. These water-soluble fibres create a soothing gel inside the digestive tract.
However, flaxseeds’ main advantage is their essential fatty acid content, as discussed above. 28.4 grams of flaxseeds contains 6 grams of ALA and 1.6 grams of LA (4:1 ratio). These essential fatty acids (in this ratio) benefit:
- immune function
- joints and ligaments
- allergies to seasonal pollens and sweet itch
- heart and blood vessel health
- respiratory health
- digestive function and gastrointestinal health
- hair and hoof strength
- energy levels
- nervousness and behavioural challenges
- horses prone to tying up
- horses with insulin resistance
Should I use whole or processed flax?
Whole flaxseeds. Flaxseeds are tiny and are not adequately chewed, leaving an intact outer hull. As a result, two things can happen: the hindgut bacteria can digest the fibrous hull and ferment the seeds’ contents. This would provide energy for your horse but nothing more since the EFAs cannot be absorbed from the caecum and large colon of the horse, or the whole seeds may escape digestion altogether and end up in the manure.
Ground flaxseeds. These produce the best bioavailable source of essential fatty acids but if you grind the flaxseeds yourself, limit the amount to two or three days’ worth and store them in the refrigerator in a sealed container. Exposure to light, heat, and moisture will trigger an oxidative rancidity reaction, making them unpalatable and unsafe to feed. Oxidation of EFAs creates free radicals, molecules chemically missing an electron and seeking to obtain one by damaging tissues throughout the body.
Flaxseed oil. This is especially vulnerable to oxidation and starts to go rancid as soon as you let air into the bottle. Naturally occurring vitamin E is an antioxidant that protects the essential fatty acids from oxygen but will quickly run out, leaving the fatty acids defenceless. Furthermore, the oil only provides fat, whereas the ground flaxseeds offer far more nutritive value.
Top tip
You should also avoid soaking or boiling whole flaxseed as this could alter its nutrient profile.
How should I add flaxseed to my horse’s diet?
If your horse is getting at least eight hours of fresh, healthy pasture during the growing season, you do not typically need to add any ground flaxseeds unless he has health issues that would benefit from it.
With heavily hay-based diets, however, ground flaxseeds will be necessary. We advise speaking to your equine nutritionist about appropriate quantities for your horse.
Horses not accustomed to eating ground flaxseeds do best when they are introduced slowly, over two to three weeks, to allow the hindgut bacterial population time to adjust.
Take-home message
Flaxseed can be a valuable tool in your horse’s nutrition programme as a source of calories and fibre, and it is an excellent source of fat, particularly omega-3. Use the ground, stabilised form to prevent rancidity and increase the nutrients’ digestibility.