Question
I am a student at National University of Colombia, and I am trying to find information on the use of linseed in equine diets. I have found several articles about linseed but few of them talk about how to provide it in the diet. Can you please help me?
Answer
Some confusion exists around linseed because there are two names for the high-fat seeds: linseed and flaxseed (flax). If you do a search on flax, you may find a lot more information because it is the more common term these days.
Flax is a small teardrop-shaped seed that has been used for centuries as a nutritional supplement for horses, due largely to its high fat content (~40%). There are two varieties, golden and brown, and both have virtually the same nutritional profile, including almost identical amounts of omega-3 fatty acids. Brown flax is usually fed to horses.
The virtues of flax stem from the high fat content and the type of fatty acids that make up that fat, as well as the high soluble fiber content. Flax is high in omega-3 fatty acids, which are essential to the horse and responsible for improving cellular integrity and balancing inflammatory response in the body. Flax is chock-full of soluble fiber that not only supplies energy to the horse but also has mucins that have a beneficial effect on gastrointestinal function.
The seeds can be fed whole and mixed into horse feed but are best if ground immediately before feeding. The traditional way to feed flax was boiling because it makes a thick, gelatinous soup that is readily consumed by horses. Boiling or grinding breaks open the hard shell to expose the most nutritious parts of the seed to digestive processes. The concern with grinding in advance of feeding or soaking in unheated water stems from the fact that there are neurotoxic cyanogenic glycosides in the flaxseed that produce cyanide when exposed to air or water. Ideally, flax should be added only to water that is boiling, not water that is on the verge of boiling. Grinding well in advance is also not recommended but grinding just before feeding is acceptable. Commercial products that are milled or ground can be safely fed because they have use a stabilization process that stops the enzymes that produce the cyanide.
Up to 100 g of flax can be fed safely, but typically horses are given between 25 and 75 g per day. Feeding 50 g will supply the amount of omega-3 fatty acids recommended for humans (adjusted for a horse’s size, of course). Fresh grass offers an abundance of omega-3 fatty acids, so horses on pasture do not usually have a deficiency of omega-3 fatty acids. Horses fed hay and grain or concentrates will benefit from additional omega-3 fatty acids.
In humans, flax can interfere with absorption of certain medications, so timing of flax consumption is important. This may be similar if the horse is on thyroid medication; flax should not be fed within two hours of receiving the medication.
There is another product on the market by the name of linseed meal or flax meal. This is not the same as ground flax. The meal is a by-product of oil production. While there can be residual fat, an average of 12%, the meal can be fed to horses as well and has some of the same benefits, even though it is not as high in the omega-3 fatty acids. Flax meal is more commonly used as a protein supplement because it has about 36% protein.
