The Natural Approach to Equine Nutrition

Horses evolved as grazers and browsers, eating with their heads and necks down, taking in small, near-constant quantities of a wide variety of grasses, twigs, scrub, leaves, etc.  These frequent small amounts of food keep them occupied and moving throughout the day.  In addition to the obvious benefit of reducing boredom related behavioral problems, the chewing increases saliva production.  Equine saliva is high in bicarbonate, which is a buffering agent - to help ward off the ulcers that are present in many domestic and traditionally kept horses.

Their stomachs are small; they can only hold approximately 2-4 gallons at any given time.  Unlike humans, who produce digestive acids in the stomach when food arrives, horses produce acid constantly.  Without being able to eat throughout most of the day, this unnatural eating pattern, combined with stall confinement, contributes to ulcers, colic and behavioral problems.

In addition, horses were not designed to eat the very rich, high carbohydrate feeds nor the rich hay grown for the dairy market.  Most hay producers grow hay that is hardy, fast growing and drought and heat/cold resistant.  These very attributes of a plant equal higher sugar content in that plant.  Just like humans are not evolved to eat the high sugar, high carb foods available today, the horse's system can eventually suffer for these diets as well.  Relatively new to the market are 'slow feeders', designed to help with this very problem.   Typically designed like a regular hay net but with smaller openings, they slow the rate of consumption, allowing the horse to nibble for hours, reducing boredom, the risk fo ulcers, stress, and even crazed feeding time antics.  Horses learn to relax and enter a more natural as well as healthier eating pattern than when "meal fed". Some slow feeder websites for information and ideas include Nibble Nets , the Freedom Feeder and the Hay Pillow

Horses have large intestines with millions of beneficial bacteria helping to digest their feed.  If the horse was subject to a change that upsets this eco-system (dramatic changes in feed, for example), the bacteria can be killed off or imbalanced, and these exotoxins become a poison to the horse.  Laminitis and founder are lurking as a dangerous possibility should the horse be unable to assimilate the overload.  You have probably heard that it is good to give your horse probiotics.  Probiotics are beneficial bacteria that would typically live in the horse’s gut. If your horse has been subject to a recent stressor that could have disrupted them (worming, antibiotics, a stressful trailering experience), a probiotic is a good idea.  For long term treatment, it is recommended to feed your horse a prebiotic, which feeds the beneficial bacteria.  Products such as Ration Plus or Farnam’s Yea-Sacc are highly recommended.

Grass hay, clean water and white salt are great basics for your horse's nutritional needs.  Red or brown colored “mineral” blocks were created for cattle, not horses.  They tend to be high in iron, which most horse diets are already too high in, and have an imbalanced mineral profile as well.  A plain white salt block is good, but your horse would need to eat a 5 lb. brick every couple months to be getting his recommended intake of salt.  So, even better is adding ~2 tablespoons of iodized salt to your horse’s diet, which helps them get both the necessary salt and iodine, an important mineral.  Iodine is utilized by the body with hormones to help regulate basal metabolic rates.  

Extremely common deficiencies in the equine diet are copper and zinc. 

Copper is involved in the formation and regeneration of bone, cartilage and connective tissue.  It is also an anti-oxidant, and is involved in pigment in the hooves and hair coat of the horse and mobilization of iron in the formation of hemoglobin.  One of the signs of a copper deficiency is a coat that tends to get sun-burned, another is anemia (anemia in horses relating to low iron count is literally undocumented), and still another is hoof wall separation.  Note also that sulfur and iron limit the absorption of copper, so you may be feeding some copper but it is not enough to off-set the imbalance. It's all about the ratio!

Zinc is an important element in glucose metabolism, immune function, hoof and hair collagen.  One of the signs of zinc deficiency is poor hoof and hair texture and inefficient glucose metabolism. 

Magnesium is deficient in nearly all horses living in the southwest (K. Watts,, although the California grown hays tend to have a decent amount of magnesium.  However, high calcium such as found in alfalfa hay blocks magnesium absorption.  It is anti-inflammatory, and a deficiency sign is excitability and nervousness. 

As mentioned above, iron is available in excess in the modern horse diet.  It has been shown that iron supplements have not been effective in improving anemia or oxygen carrying capacity of the red blood cells.  (Frederick Harper, Extension Horse Specialist, U. of Tennessee)  Iron toxicity is a real risk, it has been shown to exacerbate insulin resistance, and it blocks copper and zinc absorption as well!  Excess iron is stored in the liver or spleen, but horses have no system to eliminate these high levels.  They must be balanced out over time -that is why ratios are so important! 

Horses in Southern CA are often lacking in Omega-3 fatty acids, as these are most readily obtained through grazing live grasses and plants.  Supplementing your horse with ½ -1 cup of fresh ground or a stabilized flax product (I recommend Omega HorseShine or Horsetech's Nutra-Flax) can make an enormous difference in their skin and coat as well as overall health.  Studies have shown that horses on flax display less symptoms of allergies and insect sensitivities as well.  {Note: flax will spoil and should not be ground ahead of time, and soaking is not recommended as it has been found to release trace amounts of cyanide.  Feeding whole seeds does not allow adequate digestion, so if you do feed whole seeds try to up the quantity fed to allow for the whole seeds being passed through undigested.} Also be aware that omega-3s are considered to be anti-inflammatory, whereas omega-6s are considered to be pro-inflammatory. Flax and chia have a roughly 4:1 ratio of 3s:6s, which is right in line with the horse's natural diet. Products such as rice bran and black oil sunflower seeds can have the opposite ratio - so be aware when feeding sensitive horses.

Another important anti-oxidant and commonly deficient dietary component is Vitamin E.  Southern California horses that do not graze fresh grass do not get enough Vit E.  It can be added to your horse’s diet either through packaged Vit E supplements, or you can save money and use the gel caps for human use!   Providing vitamin E in an oil allows it to be better absorbed as it is a fat soluble vitamin, and you can mix them into their feed rations and they will eat them whole.

I would like to add my thoughts on calcium and phosphorous, due to the very high incidence of feeding either straight alfalfa or an alfalfa/oat hay diet in the SoCal area.  While many horses seem to do very well on this diet, it is not without its pitfalls and is difficult to balance.  It is especially not indicated for laminitic/foundered or insulin resistant horses.

Alfalfa is a high protein, high calcium legume hay.  An excess of calcium limits the body’s absorption of magnesium and phosphorous, among others.  A high Ca diet decreases prostocyclin (vasodilator) production and increases thromboxane (inflammatory response)… therefore, high Ca is pro-inflammatory and vasoconstrictive.  Alfalfa is not typically high in sugars/starches compared to other hays, but many horses do not tolerate alfalfa for reasons that are probably a combination of factors.  Some theories relate to the high phyto-estrogens (plant hormones), and interestingly mares tend to react negatively to alfalfa more than geldings.  Some studies point to this being due to the magnesium suppression, as they tend to become magnesium deficient during heat cycles anyway.  There is also a tendency to fungi-toxins on the leaves, and even the sugar the plant does contain, glucose, is more readily accessible by the horse’s system.  Also, in mature horses thyroid hormone levels decrease with age and when excess amounts of protein are fed.  This might be a consideration in why some horses seem to tolerate it, or did for a time but no longer can.  It is also indicated in the formation of enteroliths and increased risk of tying up.  Alfalfa is not all bad, though, it can be a good choice for adding protein, calciu and calories to the diet and can usually be safely fed in small quantities.  One should think of it as the “grain” of the hay world, and feed it with awareness and consideration for the individual. 

Oat and other cereal grain hays like barley and wheat tend to run high in starch - they average 16% sugars (whereas grass hay averages 9%), and while it is sometimes higher in phosphorous than alfalfa it often still has inadequate levels.  Feeding either oat or alfalfa “straight” can cause a severe imbalance in the Ca:P ratio, which is very important for the bones.  Phosphorous deficiency in horses can show as bone demineralization and chronic shifting lameness.  Remember that calcium can limit absorption of phosphorous.  The correct ratio for a horse is considered to be 1:1 or 2:1 (Ca:P), and alfalfa is more like 6:1.  Again, oat (and other cereal hays such as barley or the 3 ways like oat/wheat/barely) are typically quite high in sugars (specifically starch), don’t let the stemmy appearance fool you.  Starch is converted directly to glucose.  That means 100 grams starch = 100 grams of glucose when fully broken down.  In contrast, sucrose is the predominant sugar in grass hays, and only breaks down about half – so 100 grams of sucrose = 50 grams of glucose when digested.

Supplements such as vitamins, minerals, salt, and flax can be fed by mixing with soaked, unmolassed beet pulp.  Beet pulp is high in fiber and pectin, is highly digestible, and is a very low glycemic index feed.  Therefore, it can be safely fed to horses that need to lose weight as a “carrier” for their supplements, OR put on weight (due to high fiber and low index it can be fed in fairly large quantities as compared to grains – up to 30% of their fiber intake).  Soaking and rinsing the beet pulp ensures that any molasses used for dust control, flavor or as a binding agent has been removed, along with surface contaminants such as iron, but additionally it is a great way to get more water in your horse’s system. Alternatively, you can mix supplements in wet pure hay pellets such as those made by Mountain Sunrise, as they do not add any molasses or minerals to their product. 

The ideal of diet balancing is to test your hay (using a hay corer and sending it for analysis to Equianalytical) and then create a customized vit/mineral supplement based on the excesses and deficiencies in your hay. The details of this can be learned through Dr. Kellon's NRC Plus on-line training program and studying the NRC Guidelines. As a second best and probably most feasible for the average horse owner, is to feed a regional type balancer such as California Trace. It was designed to balance the most common deficiencies in west coast grown hays - but quickly it became evident that it balanced hays from east to west and even in far away places such as Poland and South Africa! It seems hay is suprisingly similar in what it has as well as lacks, at least as far as trace minerals are concerned. California Trace does not add in things the horse doesn't need, such as more iron or sugars, but instead offers appropriate amounts of trace minerals, amino acids and vitamins.

Please also consider and do not underestimate the importance of how much movement your horse gets.  Unlike predators such as dogs, cats, and people that gain comfort from the equivalent of a cozy cave, horses are prey animals that gain comfort from open spaces and fresh air.  Isolated, "pampered" and unnatural lifestyles are not in their best interests.  Their entire systems are designed for movement and a herd life, and their mental and physical health (including their hoof health!) depends on it. 

We can all only do what we can within our means and available options, but it's important to remember that these beautiful animals are relying on us to ensure their physical and mental health.  Give your horse as much movement and freedom as you possibly can, preferably with friends!  If you have your horses at home, please check out Jaime Jackson’s newest book, "Paddock Paradise".  It will help explain ways to make even a very small acreage provide the entire spectrum of your horse's lifestyle needs.  The positive impacts of getting your horse the proper nutrition and lifestyle are far reaching! 

Your horse will thank you!  :-)


We still do not know one-thousandth of one percent
of what nature has revealed to us.
Albert Einstein





The information in this article is merely the tip of the iceburg in understanding equine nutrition, of course!   Information printed was gleaned from Dr. Eleanor Kellon’s NRC Plus nutrition course (, The Equine Cushings Yahoo Group, Katy Watts clinic, website and DVDs, Equi-Analytical’s forage and grain testing database, and Sally Hugg’s article “Healthy Horse Healthy Hooves” and "Between the Twines" clinics, as well as where sited within the article.

For cutting edge information on laminitis, insulin resistance and Cushings in horses, please visit or join the Yahoo group "Equine Cushings" moderated by veterinarian Dr. Eleanor Kellon.  To get a mind blowing education in the balanced equine diet, consider taking one of Eleanor's on line nutrition classes, starting with NRC Plus.  Find out more here:



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