THE BENEFITS of feeding oil to horses are well documented and so the majority of feed rooms throughout the UK would contain a bottle or two of oil of some description.

THE BENEFITS of feeding oil to horses are well documented and so the majority of feed rooms throughout the UK would contain a bottle or two of oil of some description.

Oil is known to provide energy to the horse without creating any fizziness and feeding it generally results in a horse with a healthy shine.

Look in any horse or human magazine and you will see the promotion of products containing omega-3 fatty acids.

The advantages of feeding oily fat as an energy source, are accepted almost universally and scientists are now exploring how certain fats can have further reaching benefits to horses.

Here's a guide to what's what in the terms of fat:

Essential fatty acids
These are so called because the body requires them for good health, but cannot manufacture them itself. They must, therefore, be sourced from the horse's diet.
Fatty acids make up cell membranes and are therefore involved in all processes in the body to some degree. This means that changing the fatty acid profile of the diet can impact on a lot of systems in the body.
Research has focussed its attention on two essential fatty acid groups; omega-3 fatty acids and omega-6 fatty acids.
The body needs both omega-3s and omega-6s as both have very different but important functions. Omega-3s suppress inflammation whereas omega-6s are pro-inflammatory.
To function correctly the two must be in correct balance, it is possible to have too little or too much of either group in a diet.
It is the ratio of the two together (n6:n3 ratio) that is important with the ideal ratio being low omega-6 to high omega-3.

Balanced fatty acids
This is where the problem lies in the modern diets of both horses and humans. Modern living has thrown our n6:n3 ratio out of balance. The majority of horse's diets are likely to have too many omega-6s and not enough omega-3s.
The horse is a grazer and although its natural diet of grass may be low in oil (2-3%), the fat that is in it is rich in omega-3s.
The quantity of grass that a horse would consume in a day, if left unrestricted, would add up to quite a high daily intake of omega-3s.
This means that horses that are on a forage only diet will be receiving a healthy balance of n6:n3 in their diet.

High omega-6 fatty acids
Cereals and cereal by-products are high in omega-6 fatty acids. Many horses require extra concentrate feeding due to the level of work they are doing or to the fact that they are a poor doer or both.
As soon as we need to start feeding our horses cereals or feeds containing cereals we start to skew that important n6:n3 ratio the wrong way and the horses diet becomes high in omega-6s.
Although research in horses is limited, research in humans links a high omega-6 diet to problems ranging from depression to arthritis.
If the body has too few omega-3s then it will use omega-6s to replace them, which can affect how the body functions.

Inflammatory response
A diet high in omega-6 fatty acids can lead to inappropriate inflammatory responses in the body due to the fact that they are pro-inflammatory and without the balancing effect of the omega-3s inflammation suppressing properties.
Inappropriate inflammatory responses in horses can be seen in arthritis, allergic reactions, laminitis and exercised induced pulmonary haemorrhage (EIPH) in high performance horses.
The n6:n3 ratio is not to blame for any of these diseases, as there are many other immunological factors at work but studies have shown that supplementation with omega-3 (with linseed or fish oil) to horses on a high omega-6 (grain based) elicits a reduction in inflammatory response in cells, showing that it could help modify the inflammatory response seen in these diseases.

Sources
Omega-3 fatty acids are found in the highest concentration in fish oils and in linseed/flax oils.
Other sources that contain omega-3 in varying amounts including canola oil and soyabean oil. Omega-6 is also found in differing amounts in corn oil, cottonseed oil, soyabean oil, sunflower oil.
Although hay and pasture forages are low in total fat content, most of the fat is made up of omega-3 fatty acids. In contrast, cereal grains such as oats and corn offer primarily omega-6 fatty acids.

Which oil?
If your horse is on a forage only diet (supplemented with a general premix or low inclusion balancer) then in all likelihood they do not need any omega-3 supplementation.
If you wanted to add oil to this high forage diet for conditioning purposes, then so long as there were no issues with arthritis, allergies or laminitis, then soya bean oil would be your best choice. This contains an excellent blend of essential fatty acids (albeit slightly higher in omega-6) - but if you were only adding a glug' any vegetable oil would suit the purpose.
If your horse's diet contains cereals then there is no point in using an oil that is high in omega-6 as you will just skew the balance towards omega-6 fatty acids even more.
In these instances, the use of linseed, hemp/flax oils is probably best.
Fish oil (codliver oil) is the best source of omega-3 although it is limited to the amount that can be fed (always follow feeding instructions when using fish oils) and would need to be used in conjunction with another oil if being used for conditioning purposes.
Studies have shown that fish oil is the best oil of choice for improving fertility in stallions and mares, and only small amounts are required to achieve a response.
Research shows that using fish oil in the diet of stallions improves the function of sperm post cooling or freezing.

Feeding oil
The level of oil that most horse's receive in their concentrate feed (generally a glug' from the bottle!) will have very little impact on the entire diet.
Fed at higher levels for conditioning or performance effects (100 -500ml) it has a significant impact on the diet.
These higher levels of oil should be introduced to the horse's diet gradually over two to three weeks as it takes the horse's body some time to adjust to utilising oil effectively. Immediate effects will not be seen.
Extra vitamin E will have to be supplemented when used at these levels, the general rule of thumb is an extra 100 IU of vitamin E per 100ml of oil fed.
At these higher levels it becomes more important to ensure that the fatty acid profile of the entire diet is balanced.
Speak to a nutritionist if in doubt.

Processed oils
Another thing to be aware of is that supermarket-bought, human grade oils are processed to improve their shelf life and they are completely devoid of any essential fatty acids which would be beneficial to your horse.
They will still work as an energy source, but will not be as digestible and certainly won't supply any omega 3 or 6 fatty acids to you or your horse.
From your own point of view, stick to virgin or extra virgin olive oils, ditch the margarine and use butter instead!