The idea of feeding more fat to our horses is more than just a dietary trend. In fact, the past couple of decades have seen a huge interest in researching the effects that higher fat diets have on horses. Numerous studies have discovered that the type of fat or, more specifically, the type of oil being fed can positively impact a horse’s health, behavior and performance. These studies have also shown that some types of fats (or oils) can have negative consequences. Thus, it can be argued that not all dietary fats or oils are created equal. As a horse owner, you should be aware of the “good” versus “bad” fats being offered on the market.

Why Should We Feed More Fat to Horses?

The forages that horses eat are naturally low in fat, varying from 2 to 4% of the diet. Thus, some may wonder why we even need to add fat to their diets if horses naturally survive on low fat diets. For many horses, it is because we have confined them and then asked them to perform for us. In doing so, these horses need extra energy (calories) and other nutrients in their diets to sustain themselves. For centuries, horse owners turned to cereal grains to provide these extra calorie and nutrient requirements. However, even the cereal grains we feed our horses tend to be lower in fat; usually, at maximum, 5% of the diet. This begs the question, why feed more fat, then?

The answer as to why we now suggest feeding more fat in the diet partially lies in the shift away from feeding diets high in non-structural carbohydrates (NSC) as a source of increasing calories. We have previously discussed the basics of NSC in horse diets and it is well worth a review. Very briefly, horse diets high in NSC can lead to metabolic disorders, including obesity, behavioral issues, and others issues related to health and performance.

The other reason we suggest feeding more fat is that it is an essential nutrient. Dietary fat has always been known to be necessary for the absorption of fat-soluble vitamins A, D, E, and K. Additionally, fats are now seen as a safer alternative to increasing calories in equine diets, as they have no NSC content.

Multiple research studies in horses have also shown that diets higher in fats lead to:

  • Higher energy reserves, leading to better performance
  • Calmer behavior and less observed stereotypies
  • Improved skin and coat condition
  • Healthier hooves
  • Improved reproductive efficiency
  • Improved health for horses prone to metabolic disease
  • Reduction in risk of colic or gastric ulcers

These are just a few of the major benefits of higher fat diets for horses. Some of the more exciting discoveries have been around the benefits of the omega fatty acids seen in higher fat diets. You can learn more about this by reading our article on Omega-3 & 6 Fatty Acids in Horse Feeds.

Briefly, omega fatty acids have many important biological roles in the horse, such as cell function, nervous and immune system function, as well as roles in inflammation and tissue repair.  Furthermore, omega-6 fatty acids promote important inflammatory responses, whereas the omega-3 fatty acids promote anti-inflammatory responses. The ideal ratio of omega-6 to omega-3 fatty acids in the diet has not been established for horses. However, it is generally accepted that the ideal equine diet ratio of omega-6 to omega-3 fatty acids should be no more than 3:1.

Which Type of Fat Is Appropriate for My Horse?

Over the years, the go-to fat supplement for many horse owners has been pure vegetable oil. They are nearly 100% pure fat, are usually palatable to horses and can be easily top dressed on feeds. However, with all the research completed over the years, not all vegetable oils are seen as wise additions to equine diets. The reasoning is that some vegetable oils are much higher in omega-6 fatty acids as compared to omega-3 fatty acids. Thus, adding certain oils to equine diets skews the omega-6 to omega-3 ratio far beyond the ideal 3:1 ratio.

The best example of an oil with an out-of-balance omega fatty acid profile is corn oil. This was often the go-to oil for horses for many years. However, because the omega fatty acid ratio is so important, it is no longer advisable to supplement corn oil or other oils that are high in omega-6 fatty acids. If horse owners desire to add oil to their horse’s diet, equine nutritionists now suggest adding oils that are higher in omega-3 fatty acids to bring the omega-6 and omega-3 ratio more in balance.

The average fatty acid percentages in common oils fed to horses are:

  • Corn oil: 57% omega-6 to 3% omega-3
  • Soybean oil: 54% omega-6 to 8% omega-3
  • Rice bran oil: 33% omega-6 to 2% omega-3
  • Canola oil: 19% omega-6 to 9% omega-3
  • Flaxseed oil: 14% omega-6 to 53% omega-3
  • Fish oil (will vary by fish species): 4% omega-6 to 30% omega-3

There are many other considerations and even newer discoveries on feeding specific oils (fats) to our horses. For example, emerging research in other species is beginning to demonstrate that hemp oil is even healthier than other traditional oils. Hemp oil has increased levels of specific omega-3 fatty acids, including stearidonic acid, which are more efficiently used in the body versus others. It is also rich in omega-9 fatty acids and other oils, like fish oil, are not. Like the other omega fatty acids, omega-9’s are also beginning to show multiple health benefits when supplemented in the diet.  

Take Home Message

The bottom line is that the type of oil (fat) we add to our horse’s diets is now an important consideration. The days of grabbing any type of vegetable oil and top dressing our horse’s feed is behind us. Now, the specific types of oils we feed our horses is just as important as choosing the type of horse feeds we feed them. If you have any concerns or questions about what you are feeding your horse or need advice on the type of oil (fat) you are using, please contact us for a free, personalized feeding plan.
 
References
Harking, J.D., et al. 1992. Effect of added dietary fat on racing performance in thoroughbred horses. J. Equine Vet. Sci. 12:123-29.
Hothersall, B., Nicol, C. 2009. Role of diet and feeding in normal and stereotypic behaviors in horses. Vet. Clin. North Amer: Equine Pract. 25:167-181.
Pussillo, G, Purevjav, T. 2014. The future of fat and fatty acids in horse diets, beyond energy. Link here.
Warren, L.K. 2011. The skinny on feeding fat to horses. University of Florida, IFAS. Link here.
 

Chris Mortensen, Ph.D.