Fat Options to Help Your Horse Hold Weight During the Winter

Q. What is the best use of fats to help horses maintain weight during the cooler winter months?–Julie, Hawaii

A. Fat sources are often used for weight gain because they’re significantly more calorie-dense than carbohydrates. There are numerous products that can add fat to a horse’s diet, including:

  1. High-fat commercial performance feeds, which typically have 10-13% crude fat and when fed correctly provide all the necessary vitamins and minerals to complement the forage in the ration;
  2. High-fat feeds, such as rice bran (which contains approximately 18% fat and might or might not have added vitamin E, calcium, and other minerals) or flax seeds (which might have up to 40% fat content);
  3. Fat supplements either in feed form—which might have as much as 30% crude fat—or a dried vegetable oil at 90% fat; and
  4. Oils, which include everything from common vegetable oils such as canola oil to less well-known vegetable oils such as camelina. Fish oil is even an option.

But First…

Before you reach for your preferred fat source, though, first try to determine why your horse isn’t maintaining weight.

  • Is it just an issue of too-few calories?
  • Are your horse’s teeth in good shape?
  • Have you checked his fecal egg burden and is he on an appropriate parasite control program?
  • Have you ruled out issues such as gastric ulcers or other sources of low-grade pain that can lead to weight loss?
  • Is he in a pasture setting and being kept away from feed by other horses?

While feeding fat might indeed help with weight gain in all these scenarios, you ultimately need to fix the underlying issue, which otherwise can lead to other problems (such as colic) in the future.

Next consider if fat is the best option for your horse. Horses need to eat adequate quantities of forage each day generally between, 1.5-2% of their body weight as dry matter from forage is ideal. Check to make sure that your horse is being offered adequate forage before reaching for a fat source. Tip: Use a scale to weigh the forage you feed your horse.

Horse eating hay in snowy field

If you’re feeding plenty of hay or pasture, consider offering a fermentable fiber, such as beet pulp, that’s more easily digested and tends to yield more calories per pound than hay. This option is useful if you have a horse that’s not particularly motivated to eat hay, you can replace some of the hay with soaked beep pulp get more total calories into the ration while still honoring the need for forage.

Certainly, feeding fat is generally regarded as a safer way of adding extra calories to a ration than using higher starch options due to the risk of hindgut disturbance if too much starch is fed at one time. However, feeding large amounts of oil—especially without a gradual introductory period—can also lead to negative health consequences for the hindgut.

Choose Your Fat Source

So, assuming you decide adding a fat source is a good choice for your horse, which option is best? Most fat sources regularly fed to horses provide sources of polyunsaturated fatty acids, often referred to as omega fatty acids. Sources of omega-3 and -6 fatty acids are required in the horse’s diet, because horses lack the enzymes necessary to make these fats themselves. No fat source providing these fatty acids is inherently bad for your horse, but some sources are certainly better than others.

Often the easiest way to increase fat in the diet is to add oil to whatever you’re already feeding. My personal preference is to use an oil that contains both omega-3 and -6 fatty acids, because omega-3 fatty acids help support healthy inflammatory response and cold season grasses provide more omega-3 than -6. Therefore, by supplementing with fat sources containing omega-3 fatty acids, you’re more closely mimicking the fatty acid profile of a pasture-based diet.

For this reason, canola and soybean oils are a better choice than corn oil, because the latter contains no omega-3 fatty acids. Better still are flax oil or camelina oil, because these contain upward of two times as much omega-3 fatty acid as omega-6.

It’s important to note that researchers have not identified the ideal ratio of omega-3 to -6 fatty acids in a horse’s total diet, and it could vary depending on factors such as work level. Omega-6 fatty acids contribute to inflammation and might lead to decreased cell mediated immunity, so too much omega-6 in the diet is undesirable. While dietary omega-6 fatty acids are required, research shows it might be important to not feed them excessively. However, we have yet to determine what constitutes excessive intake

While using oil is a simple and often relatively affordable way of adding fat to a diet, oil is messy and might not be practical in all situations. This is why high-fat supplements can be beneficial. Another consideration is whether your horse also needs other essential nutrients such as trace minerals and key vitamins. The down side to oils and some fat supplements is that they contribute very little other than calories and, depending on the amount fed, might result in a diet that is lacking in key nutrients.

Therefore, a more balanced approach of using a fortified high-fat commercial feed is probably a better options if fed properly, because it will help maintain the overall balance of your horse’s diet while increasing calorie intake.

Take-Home Message

Adding fat to your horse’s diet can be a great way to increase calorie intake and maintain condition in harder keepers over the winter. However, before adding a fat source, assess the situation to determine why your horse is struggling to maintain weight and then take time to determine which fat source makes the most sense based on your horse’s overall diet.