Chewing the Fat on Oils

By Kim Hallin

Although the natural diets of horses have always contained small amounts of oil, research has shown that horses are adept at utilizing much higher percentages of oil in their diets.  As it turns out, horses are able to efficiently digest, metabolize and utilize large quantities of oil as an energy source through a process called ‘fatty acid oxidation’.

Because oil is very energy dense, it yields about 2 ¼ times more energy than starch or protein. Oil (fat) also provides a “cooler”, less “fizzy” type of energy than sugars and starches.  However, it is important to understand that not all oil is created equal.  Here are the key things you need to know when selecting an oil to feed your horse:

Refined vs. Unrefined

Refined oils including corn, soy, ricebran, canola, linseed and sunflower are all extracted using heat and a chemical solvent, then bleached and deodorized.  This refining process is done to strip the oils of so-called “impurities” (which can often be the source of valuable nutrients).  Refined oils have been shown to cause an increase in inflammation, which makes them potentially dangerous for your horse.  The most commonly fed oils for horses, corn and soybean, are also the most likely to cause inflammation due to their high linoleic acid content.

By contrast, unrefined oils – including the powdered coconut oil in Power Stance – are processed under minimal heat (cold or expeller pressed).  These oils maintain their natural antioxidants such as vitamin E, beta carotene, tocotrienols and other tocopherols. They also have a longer shelf life and are more easily digested.  These oils support the body’s normal inflammatory responses.

Saturated vs Unsaturated Fats

Saturated fats (SFA’s) are solid at room temperature.  Chemically speaking, they contain no double bonds between carbon atoms.  Most saturated fats are animal fats but coconut oil and palm kernel oil also fall into this category.  Among the oils used in horse feed, coconut oil is unique in that 90% of the fatty acids in it are saturated.

Mono-unsaturated fats (MUFA’s) are liquid at room temperature.  They contain a single double bond between carbon atoms. Vegetable fats, rice bran and olive oil fall into this category.

Polyunsaturated fats (PUFA’s) are also liquid at room temperature.  They contain more than one double bond between carbon atoms.  All essential fatty acids (EFA’s) are polyunsaturated. Essential Fatty Acids (EFA’s) are critical to produce hormones and healthy cell membranes.  Essential Fatty Acids cannot be manufactured or synthesized by the horse’s body so they must be consumed in the diet.  The fats in pasture grass as well as grass hay and legume hay are highly weighted toward Polyunsaturated fats so horses that have adequate forage in their diets will get plenty of PUFA’s.  In terms of oils, sunflower oil, corn oil and soyabean oil contain the highest amounts of PUFA’s.

The graph below shows the different proportions of saturated, monounsaturated and polyunsaturated fatty acids in many oils commonly fed to horses and/or people.


Studies in which animal fat (highly saturated fat, rich in long and medium chain fatty acids) is fed, consistently showed increased resting muscle glycogen concentrations and increased glycogen utilization during high intensity exercise.  This is not the case in studies where corn oil and soybean oil (both long chain polyunsaturated fats) are fed.  Like animal fat, coconut oil is highly saturated with a high content of medium chain fatty acids that impart a wide range of positive health benefits.

MCTs provide about ten percent fewer calories than LCTs (8.3 calories per gram for MCTs versus 9 calories per gram for LCTs). But this is just one of the unique advantages of MCTs. More importantly, reduced chain length also means that MCTs are more rapidly absorbed by the body and more quickly metabolized (burned) as fuel. The result of this accelerated metabolic conversion is that instead of being stored as fat, the calories contained in MCTs are very efficiently converted into fuel for immediate use by organs and muscles. MCTs are thus a good choice for horses with increased energy needs, such as those that are growing, recovering from injury, needing to gain weight, or in regular work.

In addition to their lower caloric content than LCTs, MCTs are not stored in fat deposits in the body as much as LCTs are.  They have also been shown to enhance thermogenesis (i.e., fat burning).  So MCTs seem to offer a triple approach to weight loss – they (1) have a lower calorie content than other fats, (2) are minimally stored as fat, and (3) contribute to enhanced metabolism to burn even more calories.

This chart shows the proportion of short, medium and long chain fatty acids in some of the fats commonly fed to horses.

 Pasture forage typically contains 2% to 4% fat and its Omega-3 content is generally four to six times higher than its Omega-6 content. So, if your horse gets any amount of green grass daily, you’ll probably want to opt for an oil with a fairly neutral ratio, such as coconut or palm kernel oil. However, if your horse is on a strictly grain/hay diet, with no green grass at all, then you may want to consider supplementing with oils higher in Omega 3’s such as linseed/flax oil or chia seeds. However, oils that are much higher in Omega 6’s than Omega 3’s, such as rice bran, sunflower, soybean and corn should be used only with extreme caution and in combination with other fats high in Omega 3’s!

This graph illustrates the proportion of Omega 3 to Omega 6 fatty acids in some of the oils commonly fed to horses.

Another benefit of feeding an oil-rich diet is that diets rich in oils produce significantly less heat waste than fermentable carbohydrates, roughages and proteins.  Horses supplemented with oil have been reported to have lower mean body temperatures even in hot conditions than those consuming high roughage and/or high grain diets.

For me, when it comes to choosing an oil to supplement my senior horse’s diet of pasture grass, grass hay and Cool Stance… after “chewing the fat”, I choose Power Stance (powdered coconut oil).

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