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The Truth about Feeding Horses Corn Oil

My horse has a dull coat and could stand to gain some weight, so my trainer suggested adding corn oil to his grain, for extra fat. But I’ve read recently that corn oil actually isn’t that good for horses – is that true?  I’m confused! Thanks for your help, JR, Maine


Dear JR,

Adding fat to your horse’s diet is a great way to add calories for weight gain and essential fatty acids to improve the coat.  But you’re correct that using corn oil isn’t the right way to go about it.  In fact, you might be doing more harm than good!

That’s because all fats are not created equal.  Corn oil contains almost all Omega 6 fatty acids—generally pro-inflammatory—and very little of the anti-inflammatory Omega 3 fatty acids that have so many health benefits.  While our bodies need both types, keeping the proper balance between the two is important.  For horses, experts feel that a ratio somewhere in the range of one part Omega 6 to two parts Omega 3 (a 1:2 ratio) or even a 1:4 ratio is ideal.  However, our methods of modern horse keeping have shifted the balance by restricting access to Omega 3-rich fresh grass while providing feed high in Omega 6 fatty acids such as grain-based concentrates. 

To help you better understand where these two types of essential fatty acids come from and how the balance easily becomes skewed towards the pro-inflammatory Omega 6 side, here’s a chart of the Omega 6 to Omega 3 ratios in some common horse feeds:

Feed Omega 6:Omega 3
Pasture 1:5, good
Commercial, fortified grain 8:1
Whole grains: oats, corn, barley, wheat, rice 24:1
Vegetable oils: corn, sunflower 87:1, 199:1!
Vegetable oils: canola, soybean 3:1, 7:1
Flax seed 1:4, good
Fish oil (includes the specific Omega 3s EPA & DHA) Virtually all Omega3!

In a perfect world, we’d all keep our horses turned out on green grass for its benefits to the body as well as the mind!  But since that’s not realistic for most people, just try to feed as little grain and grain oil as possible to avoid filling your horse with pro-inflammatory Omega 6 fatty acids—instead use a multi-vitamin/mineral supplement or ration balancer to fill any nutritional gaps from your forage.  Then if you want to add fat for extra calories or a shiny coat, use flax seed or fish oil and fill your horse with healthy, anti-inflammatory Omega 3 fatty acids!

Lydia F. Gray, DVM, MA SmartPak Staff Veterinarian and Medical Director Dr. Lydia Gray has earned a Bachelor of Science in agriculture, a Doctor of Veterinary Medicine (DVM), and a Master of Arts focusing on interpersonal and organizational communication. After “retiring” from private practice, she put her experience and education to work as the American Association of Equine Practitioner’s first-ever Director of Owner Education. Dr. Gray continues to provide health and nutrition information to horse owners through her position at SmartPak, through publication in more than a dozen general and trade publications, and through presentations around the country. She is the very proud owner of a Trakehner named Newman that she actively competes with in dressage and combined driving. In addition to memberships in the USDF and USEF, Dr. Gray is also a member of the Illinois Dressage and Combined Training Association (IDCTA). She is a USDF “L” Program Graduate and is currently working on her Bronze Medal. Find Dr. Gray on Google+

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64 comments on “The Truth about Feeding Horses Corn Oil
  1. Karen s says:

    what about olive oil? I imagine most horses would not be thrilled with the taste of fish oil.

  2. Kathy Baker says:

    Does whole corn have the same omega ratio as the oil? Why would you not feed whole corn? Or would? (I don’t but I have a client that does.) Thank you

    • SmartPak SmartPak says:

      Hi Kathy,

      Whole corn has basically the same RATIO of omega 6s to omega 3s as corn oil, it just contains less of them since it is not pure fat but the whole seed. Many in the horse industry choose not to feed corn to their horses since it contains high amounts of sugars and starches which can make some horses “hot” and worsen certain metabolic conditions. It’s also not a high quality source of protein, since it does not contain enough of all of the essential amino acids, most notably lysine and tryptophan. There are probably better feedstuffs to provide your horse depending on if the goal is weight gain, shiny coat, warmth in the winter, better topline, increased energy and stamina, etc.

  3. Tracy says:

    What would you recommend for a horse who is allergic to flaxseed in all forms. He’s on Triple crown senior, buckeye gro n win, vegetable oil and alfalfa cubes. Farm only provides first cutting hay at 5 flakes per day only. Reason for me adding alfalfa cubes to his diet. Any suggestions would be great!

    • Sonia says:

      I noticed this was posted 10 months ago…. I also feed Buckeye Gro n wim. It says it on the bag that it contains flaxseed. Just sayin’. ;:/

  4. Joan says:

    What about rice bran? I give rice bran pellets to help aged horses maintain weight and they love it.

    • SmartPak SmartPak says:

      Hi Joan,

      Rice bran has an omega 6:omega 3 ratio of about 30 to 1. As a part of an otherwise balance diet, rice bran is an excellent way to add additional calories from fat. However because this ratio is on the higher side, we recommend also adding in an Omega 3 supplement when feeding a considerable amount of rice bran to help bring the Omega ratio back into better balance.

      • Kathy says:

        I already use the rice bran added to my Defiance Sr low starch high fat horse feed. When you say add an Omega 3 supplement, what is that? And how does it come? I am now feeding my 24 year old apendix 6 cans (each can is about 12 oz) of Defiance, 4 cups rice bran and 2 scoops of Equipride. What else can I add to this mixture that he gets once a day to add some weight on him. His teeth are pretty much ground down to the gums and he has even lost a few. I have found them in his feed pan.

        • SmartPak SmartPak says:

          Hi Kathy, thanks for your question. Our first recommendation is to consult your vet regarding your horse’s weight loss as well as his dental issues. Your vet will be able to help you formulate a diet that is safe and appropriate for him. Secondly, your question doesn’t mention if he is receiving any hay or long stem forage, but if he has few teeth, this may be difficult for him. If that is the case, then it is important that you add in a different source of roughage in his diet such as soaked hay pellets or cubes. For additional calories, you could also consider adding soaked beet pulp, another easy-to-chew source of fiber. Lastly you mention that he is fed once per day. Senior horses tend to do best with several meals spread throughout the day, so if you can, try to add in another meal daily to keep his intake up. Best of luck!

  5. cookie says:

    i am wondering about sunflower seeds? my horse was on them when i got her 3 months ago, coat looks great but are they balanced in omegas??

    • SmartPak SmartPak says:

      Hi Cookie,

      Unfortunately Sunflower seeds have a very undesirable Omega 3 to Omega 6 ratio. They contain nearly 200 parts Omega 6 Fatty Acids to 1 part Omega 3; therefore we recommend choosing an alternate product for coat health. A supplement that contains Flax Seed or Chia Seed can not only help you see a shiny coat but they provide an excellent Omega 3 to 6 ratio as well.

  6. What is the ratio for Cocosoya oil?

    • SmartPak SmartPak says:

      Hi Betty,

      We do not currently carry Cocosoya oil but can certainly speak to our product Cocosoya Ultra SP which comes as a powdered supplement. In the Cocosoya Ultra SP, we are providing a level of 2.4 to 1 omega 6 vs. 3. The addition of flax seed in this formula provides an extra level of omega 3 fatty acids. There is also a strong level of omega 6’s coming from rice bran in this formula vs. what would come in just the oil. If you are currently feeding a Cocosoya oil, we would recommend that you contact the manufacturer to see what the ratio of omega 6s to omega 3s is for that particular product. We hope this helps!

  7. Kirsten says:

    Coconut oil and chia seed?

  8. Brittany says:

    My horses are currently getting soybean oil along with grain & hay in their diet. I was thinking of adding SmartOmega3 to their diet… how can I be sure they are getting the correct balance, in terms of enough of each?

  9. Hayley says:

    You keep recommending Fax Seeds as a good Omega3 suppliment but I’m wondering how much do you feed per day in their feed? I.e. how many grams would be ideal? Do you just buy the normal Flax Seeds off the supermarket bench and mix in their feed?

    • SmartPak SmartPak says:

      Hi Hayley, thanks for your question. Typically flax seed supplements provide 1-3 ounces of flax seed per serving, depending on your horse’s size and needs. We recommend purchasing a ground, stabilized form of flax seed, which is available in many equine supplements. Flax seed is better utilized by the horse when it is ground, however it also needs to be stabilized or it can go bad quickly. Two customers favorites are SmartOmega 3 Ultra and Omega Horseshine. Please let us know if you have additional questions!

      SmartOmega 3 Ultra:

      Omega Horseshine:

      • Candy says:

        What feed stuff is better then corn. I was going to feed my horse corn, sweet feed with some oil added. Also, does the supplements add the calories needed too?

        • allison says:

          Corn is a terrible food source for horses. Not only are the fat and omega 3 to 6 ratios off as explained above, but corn and corn oil has been linked to several different metabolic disorders. Corn is super high in starch and sugars, without getting super technical its the wring kind of sugars and a horse cannot digest corn anyway. (Neither can people digest corn but that’s another conversation!) Corn has also been directly linked to a resurgence of white line disease in the south. Corn also has the potential to make horses very hot and jittery. I feed southern States triple crown senior and triple crown complete. Both of those feeds are beet pulp based and contain distillers dried grains instead of raw corn. They are expensive and hard to find so if these are not options for you then look around at your local feed store. Try and find a grain with no corn or as little corn as possible. Good luck!

  10. jamie says:

    Hi I was just wondering about flax seed oil and whether it has the simular ratio as regular flax seed? I’ve got a young geldong that was abused and malnurished. We’ve got most of the weight back on but I wanted to add something to kinda help now that were working on building up his muscle.

  11. Candy says:

    Someone I know adds soybean oil to their horses sweet feed for extra calories in the winter. What do you think?

  12. Christy says:

    My vet recommended I feed my horse corn oil to help in digestion and for the extra fat. My horse does not sweat (it is improving, we are giving him medication) and is kind of overweight. I just read this article and I’m wondering if what she is saying is correct? I am feeding him the special formula safe choice and we just switched him over to T&A hay. What is your take on this..?

  13. nehir says:

    Hi, if anyone know, can i give “hazelnut oil” to my horse? it is cheap in my country and rich in omega 3. Or I will just give olive oil I guess.

  14. Wendy says:

    I find this very confusing. I just had my daughters 13 y/o Arab examined by my vet because he seemed to be losing weight. She found no medical condition and we floated his teeth. Her recommendaiton was that I add 8 oz of corn oil to his diet and switch him from Purina Stragety to Senior. I already had him on Cool Calories and Beet Pulb (which he hates) and he has 24/7 access to a round bale.

    • Maria says:

      Some vets it would seem are like some medical doctors who didn’t receive alot of education on Nutrition

    • Roxanne Trusty says:

      Unfortunately, many vets receive pay outs from feeds they promote or recommend only one feed as a fall back. The trend I have noticed as a feed store employee is that 99% of customers that come in with vet recommendations all are given that exact same brand recommendation, regardless of their horses individual needs. As a nutrition consultant that has an educational focus on nutrition rather that vet science, I know that there are much better feed choices than what those vets are recommending and politely offer information on other feeds that would provide a balanced diet for their specific horse.

  15. Karen says:

    Will fish oil make my horse hot?

    • SmartPak SmartPak says:

      Thanks for your question, Karen! Fats are often referred to as a “cool” source of calories for horses. This is because adding additional fat to a horse’s diet does not impact blood sugar, and so fats should not cause a horse to become “hot” or have an increase in short-term energy. A key point to understand, however, is that generally fish oil is supplemented in smaller quantities with the goal of balancing the Omega 3 to 6 ratio to support cellular health, rather than as a source of energy for the horse. Essentially what this means is that supplementing your horse’s diet with fish oil should provide excellent health benefits without impacting your horse’s energy levels. – SmartPaker Casey

  16. Sara says:

    What about plain extra virgin coconut oil? I have a few picky eaters that won’t eat powders like SmartOmega. I’d like to work their dry itchy skin/coat issues internally rather than just externally.

    • SmartPak SmartPak says:

      Hi Sara, thanks for your question! extra virgin coconut oil is low in omega 6 fatty acids, however it offers virtually no omega 3 fatty acids.  This particular oil would not make an ideal choice because it will not be able to help the omega 6 to omega 3 balance in your horse’s diet.  We would encourage you to consider a different type of oil that will be able to provide a good source of omega 3’s such as flax oil or fish oil. – SmartPaker Casey

  17. Nicole Rosa says:

    What are your thoughts on wheat germ oil? Thank you.

    • SmartPak SmartPak says:

      Hi Nicole, there are some health benefits to feeding wheat germ oil, such as it being a good source of lecithin, vitamin E and octacosanol. However, this oil is significantly higher in Omega 6 fatty acids than Omega 3 fatty acids. For this reason, if your goal is to help balance your horse’s Omega 3 to Omga 6 ratio, this oil would not be ideal. You would have better luck choosing fat sources that we know are higher in Omega 3 fatty acids such as flax seed or fish oil. – SmartPaker Casey

  18. missyj says:

    Hi. I have a 4 year old Peruvian Paso Stallion that I have been feeding Strategy Healthy Edge for some time now. How do you feel about the overall complete balance of this feed and do you recommend adding flax seed or fish oil to this. He is on limited grass with free choice high quality Bermuda grass hay? Any suggestions that would increase his health benefits WITHOUT making him hot would be greatly appreciated.

  19. Kendra says:

    So, after reading everyone’s comments and suggestions, is soybean oil ok to feed to your horses? I had my mare on the cocosoya oil but I wanted to change her to something that was not as expensive. Any tips?

    • SmartPak SmartPak says:

      Hi Kendra, thanks for asking! Soybean oil has an omega 6 to 3 ratio of about 7:1. Keep in mind that the ideal ratio of omega 6 to 3 in the horse’s overall diet would be 1:2, or as much as 1:4. If you’re looking to add a bit of healthy fat to your horse’s diet for cellular health, some of our favorite sources that are rich in omega 3’s are flax seed, chia seed, and fish oil. However, if you’re looking to add large amounts of fat for purposes such as weight gain, soybean oil is an option that horses generally find palatable. You could also consider canola oil which has an omega 6 to 3 ratio of 3:1. – Dr. Lydia Gray

  20. francisco says:

    I was told to feed a mare for weight gain arround 20cc of corn oil. We are also feeding this to other horses for energy purposes. I’ve read here that is not good, that it would be better to feed them canola oil. I have access to fish oil too, so I was wondering how much of each oil I should give to the horses in order to keep a good balance between omegas but not sacrificing the weight gain or energy source of vegetable oil.Thanks.

    • SmartPak SmartPak says:

      Hi Fransisco, thanks for your question. Our recommendation is to use a supplement designed for horses, to ensure that you get the right balance of omega fatty acids, plus calories for weight gain. In addition to being messy, oils can spoil quickly if not stored properly, and many horses may be picky about straight fish oil. A few customer favorites to consider are Cocosoya Ultra SP (, Gleam & Gain Supreme 60 (, and SmartGain 4 ( – SmartPaker Kerri

  21. Courtney Bagnell says:

    I recently purchased an appendix Quarter Horse mare that recently weaned her colt. She is still recovering from the stress of weaning and overall supplementation taken by the colt, so I am trying to get her weight back up to normal before breeding her in the spring. I recently added Canola Oil to her Strategy/alfalfa mix and am wondering if the addition of Vitamin E supplements will suffice the Omega 3/Omega 6 ratio?

    • SmartPak SmartPak says:

      Hi Courtney, thanks for asking! Supplementing with additional vitamin E can often be beneficial for horses, however adding more vitamin E to the diet will have no impact on the ratio of omega 3’s to omega 6’s. If canola oil has been beneficial for putting weight on your mare, you could consider adding something to her diet with a better ratio of 3’s to 6’s to help bring that ratio closer to the ideal. You could take a look at products containing flax seed, chia seed, or fish oil which are all power-packed with omega 3’s: – SmartPaker Casey

  22. Deb says:

    you still havn’t addressed if olive oil is ok

  23. Deb says:

    You still have not addressed the question asked” is olive oil ok or can you mix your own omega 3 and 6 oils” and what ratio?

    • SmartPak SmartPak says:

      Hi Deb, we’re so sorry about that! This one must have slipped by us, we’ll keep a sharper eye! Although olive oil is better than many other potential options such as corn oil, it still has an estimated ratio of omega 3’s to 6’s of about 0.09:1. Based on that, your best options are still sources such as flax seed and fish oil. It’s true that if one were to introduce liquid fish oil, palatability would very likely be a problem. Keep in mind, however, that supplements using fish oil as an ingredient are usually using a refined and virtually odor-free form that most horses have no problem with as a component of the supplement. – Dr. Lydia Gray

      • katherine richards says:

        I have been reading labels and concerned with source of fats in high fat feed, which seems so popular now. But it seems all the benefits of an expensive feed are overshadowed by those omega 6. So now I have switched to a low fat, and add my own oils , the feed is cheaper, does not require preservatives, and my guys like it more, and isnt that whats its all about for them, the good times of EATING GOOD TASTING meals… plus high omega 3 oils are less likely to contain GMO tainted.

  24. tonnie says:

    Hi I would like to know about vegetable oil and if it also helps lube there insides thanks

    • SmartPak SmartPak says:

      Hi Tonnie, thanks for your question! Vegetable oil will be digested and absorbed by the digestive tract as a source of fat in the diet. However, sometimes veterinarians will administer mineral oil via stomach tube when a horse is experiencing colic to help surround and infiltrate impactions and encourage their movement through the digestive tract. So, you are correct that oils may be used, but it would be the petroleum-based mineral oil as opposed to a source of fat like vegetable oil. It’s also worth noting that long-term use of mineral oil is not recommended. – Dr. Lydia Gray

  25. Madeline says:

    I want to find some oil to use in treats. I would use flaxseed oil but I am concerned about potential poisoning from frost. Would it be ok to use a small amount of canola oil

  26. Madeline says:

    Or would it be better to use olive oil?

    • SmartPak SmartPak says:

      Hi Madeline, thanks for your question! In terms of using an oil with a beneficial ratio of omega 3’s to omega 6’s, flax seed oil is excellent. Another option to consider would be canola oil. Kudos to you for being aware of the healthy fats, and know that in this case where such small amounts will be going into treats (to which I’ll assume your horse isn’t having too many of), the amount provided in these treats shouldn’t be enough to cause an imbalance in his diet. – Dr. Lydia Gray

  27. JUDI says:

    I bough a jug of Flax seed oil but it is 50% mixed with Soy Oil, is that safe for my horses? Says 2 oz for 1000 pound horse,I was going to feed a capfull daily a month before the big shed out,is that safe?

    • SmartPak SmartPak says:

      Hi Judi, thanks for your question! While pure flaxseed oil will have a better omega 3 to omega 6 ratio, soybean oil and soybeans are commonly fed to horses. It sounds like the product you’re using was formulated for horses specifically and that you’re following the serving directions as specified on the product label. However, if you have specific questions regarding the product and its use, you’re best served reaching out to the manufacturer, as they will be experts on that particular product- Dr. Lydia Gray

  28. Karla says:

    I see you totally recommend using flax seed or fish oil to enhance skin and coat! But nothin was ever posted on how much you should feed a day 1/2cup 1cup exc…. Also are there any brands you prefer or anything off the shelf from the grocery store works?!?!?

    • SmartPak SmartPak says:

      Hi Karla, thanks for your question! You are correct that flax seed and
      fish oil are two of our favorite sources of omega 3 fatty acids. In
      regard to your question about how much to feed, the beauty is that
      nowadays there are so many excellent products available that have been
      specifically designed for horses. Another benefit to these products is
      that they are almost always stabilized to help protect the fat in the
      supplement, which is especially important when considering ingredients
      like flax seed. In general, the average serving size for these types of
      supplements will range between 1-2 ounces. Two of our favorite products
      are SmartShine, which contains stabilized flax seed meal, and
      SmartShine Ultra, which adds the benefit of fish oil. – Dr. Lydia Gray

  29. Kim Mileo says:

    I have been feeding soybean oil to my endurance mare that has a history of tying up. It has been VERY helpful but it is messy. I’d like to find a powder or pellet that would do the same. We give her 1 cup daily with her grain and other supplements. What do you recommend as a suitable replacement for the soybean oil?

    • SmartPak SmartPak says:

      Hi Kim, thank you for asking! It’s fantastic that you’ve found a product that has helped your mare, and I can imagine that dealing with the oil can be quite messy. If you’re looking for an alternative to the oil, I would recommend you take a look at Cool Calories 100 (, which is a powder fat supplement. I have personal experience with this product, as my Trakehner gelding has been on it for years. Cool Calories 100 is a palatable, less messy way to provide extra fat to your horse. Dr. Lydia Gray

  30. Peggy Neff says:

    i have a horse that is a cribber. She started to show colicing a month ago or gas colic the barn manager said. So the vet said to put Corn oil in her feed. So we added the corn oil she was also on mare magic cause she acts up when in season. Which the mare magic didn’t help a whole lot so I changed to Vita-Calm like a week or two later she started to become very aggressive to the other horses and people trying to bit, rearing up when on the lead. I thought maybe it was the cold weather and not being able to run. The barn manager said she was getting worse that the vet said she should have blood work done to see what was going on. So I said take her off the Vitacalm she that seem like when she started to act worse. Could this be it or could it be the corn oil that she is on. Should I stop that too? Help??

  31. Dianna says:

    I have not read through the entirety of the responses, but, I have to say that I do not agree with the fact that corn oil is bad (for horses) though the research on humans is conclusive about the Omega’s being “bad for humans”. But I think it I more of a “balance” in what you are doing (for the record, I use soy/veg. oil, and I try to balance my horse’s entire diet so that 15-20% of all calories are coming from “fat”).

    Anyway, since forage contains almost exclusively omega-3 fatty acids, we you look at the entire diet you are feeding your horse, the addition of X amount of corn oil over a 24-hour period is probably going to keep the ratio of Omega-3 and 6’s balanced and not slant the diet to where the omega 6’s are more abundant than the omega 3’s.

    As I understand it, getting rid of “inflammation” is not necessarily a good thing, as inflammation and anti-inflammation work together, with inflammation being important to the horse’s tissue repair process (particularly in acute injuries).

  32. Valery says:

    Interested in knowing the omega 3-6 ratio and your thoughts on feeding Camelina oil to horses?

  33. Josh says:

    Hi, I was wondering what a good supplement would be to put weight on a horse fast? I thought about using a weight supplement oil they sell at the local feed store but it has corn oil in it.. I have a 7 year old mare that weaned a foal back in March. I wormed her and feed her extra but she dosent seem to be gaining much weight and her teeth are good. I really need to put the weight on her fast but im not sure what to do! Any feed/supplement reccomendations are greatly appriciated. Thanks 🙂

  34. Janet says:

    I would like to use some type of SiIMPLE supplement to my 23 year old gelding’s food to promote some weight gain going into the winter. He is on a good Senior feed with the addition of flaxseed, hoof supplement and Cosequin. He is out on grass about 6 hours a day and has access to hay in the evening. Additionally, his teeth are good but low. I have considered adding corn oil but am confused about amount and the implications that it could cause inflammation and/or white line disease.

  35. Nel says:

    Hi there,
    My horse lost a lot of weight after an impaction colic (about 3 weeks ago) and has kept loosing weight, despite having changed his feed to a higher calorie diet. Apart from supplementing with Red Cell (his blood count wasn’t looking too good), my vet has recommended to drastically increase his calorie intake for the next 2 months just to get his weight back on. This includes adding more alfalfa to his diet and 8oz of corn oil twice a day. (I have not started yet)
    Apart from reading your reviews about corn oil, I have also heard many sources are contaminated (pesticides etc). I read that you have recommended a few different oils, but specifically for weight gain, comparing the dose of 16oz corn oil a day, what oil and in which doses would you recommend in a case like this?

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