Sound principles of Equine Nutrition can sometimes evade the average horse owner, there are so many Equine Nutrition myths out there and the feeding of linseeds is no exception!
First of all, let’s get one thing straightened out… linseeds and flaxseeds and flax are all one and the same!
The addition of linseeds to the horse’s diet is an excellent choice for any horse and particularly in cases where the horse is struggling with inflammatory or immune conditions.
Linseeds have a high oil content of around 41% and are commonly used in equine nutrition for their high Omega 3 fatty acid content. They are a cost effective and economical way to boost Omega 3’s in the horse’s diet. Linseeds are a particularly good choice, because their Omega 3 to 6 ratio is very similar to that of grass, the natural diet of the horse!
The Omega 3 and Omega 6 group of essential fatty acids are key players in many bodily functions and are extremely important for a healthy physiology. They are referred to as ‘essential’ because they must be present in adequate amounts in the diet and cannot be manufactured in the body.
The Omega 6’s are needed for inflammatory and innate immune reactions, which means they are considered to be pro-inflammatory. Whereas the Omega 3’s have the opposite function. They are the counter-regulatory substance of inflammation and immune reaction - in other words, they have the ability to control inflammation.
Omega 3 deficiency in humans is implicated in many problems from compromised foetal brain development to heart conditions, cancer and arthritis. Deficiency usually results from a lack of proper nutritional intake - for example, diets low in fresh fruits, vegetables, whole grains and quality sources of naturally-grown meat and eggs.
For horses, the results of improper nutrition are similar, but the lack of Omega 3’s is usually caused by grass restriction or diets with hay as the main forage. Green grass has an Omega 3 to 6 ratio of about 4:1 but when cured as hay, the Omega 3 content is all but lost. One study found that when the grass is dried for hay and stored for only 140 days, it loses - on average - 70.3% of its Omega 3 content. The study showed the Omega 6 content in the hay remained stable.
So horses not on fresh pasture are likely to be deficient on Omega 3’s. But even if the horse is on grass, high grain diets such as corn, barley, sunflower seeds, bran and seed meals such as soybean, or vegetable oils, can also cause deficiency symptoms. This is because these feedstuffs have an inverted Omega 3 to 6 ratio, meaning the Omega 6’s are much higher. Remember… it’s the Omega 6’s that are pro-inflammatory and enhance immune reactions. A relevant example of this ratio difference in common feedstuffs shows up when comparing the Omega 3 to 6 balance of linseed oil to sunflower oil. See the table below:
Linseeds contain compounds called cyanogenic glycosides. When processed in the horses gut these cyanogenic glycosides are exposed to an enzyme which converts it to hydrogen cyanide, which in turn can lead to cyanide poisoning. However, a recent study confirmed that stomach acid inactivates the enzymes that interact with the cyanogenic glycosides. This explains why poisoning in species such as equids, with a highly acidic stomach, is not commonly observed.
There has not been one reported case of cyanide poisoning in the horse from feeding linseeds in reasonable quantities.
Myths are common in Equine Nutrition and within the horse industry in general and the info surrounding linseed preparation is no exception! Some say you need to soak it, others say it needs to be boiled, both to make it safer and more digestible.
These two myths couldn’t be further from the truth. The pre-cursors for cyanide production are actually increased with soaking and heat destroys Omega 3’s. So soaking and boiling linseeds is definitely a big NO NO!
It is generally considered a good idea, however, to grind the seed before feeding as when it’s fed whole, much of the seed seems to come out the other end, intact! The birds and worms may like this but it’s not much good for your horse.
It does need to be ground fresh though as the Omega 3’s denature and go rancid quickly when exposed to oxygen. So keeping a small coffee grinder in the feed room is a handy way to achieve this. I often suggest to clients that they grind large batches, maybe a few week’s worths at a time, and store it in the freezer.
Another option is to feed linseed oil. But don’t get sucked into buying large drums of it at the feed store, (even if it says it’s feed/livestock grade) unless it is labelled as cold pressed ‘food grade’ and refrigerated. It’s probably been sitting around for who knows how long in warm temperatures. Personally, I only use ‘human food grade’ cold pressed oil from the health food store as I know it is fresh and of good quality. ‘Melrose’ is a good brand and ‘Vet All Natural’ also does a pet version which may be a little cheaper.
What about linseed meal? The ‘meal’ is what’s left over after the oil has been extracted, so if you’re feeding it for the Omega 3 content you’ll be wasting your money. It is, however, a reasonable source of protein.
This depends on why you’re feeding it.
For horses with restricted grass diets, being fed large quantities of hay or grain, the recommended dose is between 120-170g/day for the average sized horse. This would also be the dose for horses suffering from inflammatory diseases or immune system dysfunction.
If you just want to see some improvements in coat and skin health then as little as 60g/day can have visible effects.
If feeding linseed oil, divide these quantities by 3. For example, if you calculate that you need to feed 150g of linseeds but want to feed oil, then replace 150g of seeds with 50ml of oil.
And the good news… linseeds have a very low sugar/starch content, around 4.5%, so are safe for insulin resistant and horses suffering from Cushings Syndrome.
If you still feel uncomfortable feeding linseeds to your horse and if you find the oil difficult to find or too expensive, the other option would be to feed chia seeds instead. Chia seeds are also high in Omega 3 fatty acids but their oil content is slightly lower. So if using chia, use 1.5 times as much. For example, if you need to feed 150g of linseeds times this by 1.5 for chia, so it would be 225g. Recent research suggests that Chia seeds are also best fed freshly ground to maximise oil absorption.