H-Squared Wellness

Horse and Human Health and Nutrition

Nutrition Information for Horses

When was the last time you read a food label?  Now, when was the last time you read the food label on your horse's feed bag?  They can be tricky things, food/feed labels!!  Most of us have a hard enough time keeping up with our own food labels, much less our horses'.  The real concern is not that we are feeding our horses one feed or another, but that when we combine the grain with a hoof supplement, a coat conditioner, a vitamin supplement, herbs and so on ... what are our horses actually getting?  If we add up all the nutrients in those products, are we giving our horses too much or too little?

All horses need energy (found in protein, carbohydrates and fats), minerals, vitamins and water to meet their nutritional requirements.  Horses should be fed based on their nutritional requirements and not all horses need the same feed.  Horses in competition will have different nutritional requirements than the horse that goes out on the trail 2-3 times per week.  An inactive 1000-pound horse needs about 16,000 calories per day, while a 1000-pound horse in regular work 5-6 days a week needs about 24,000 calories per day. An inactive horse can usually meet its energy requirements from a good-quality forage such as hay or good pasture.  As the level of work increases, the energy requirements increase and often a concentrated feed is added to the diet.


Below is a brief overview of the nutritional components your horse needs to maintain optimal health.  For a personalized diet analysis, schedule a consult with me to see if your horse is getting what he/she needs!  See the rates and services page for more information.


Water is often overlooked as a nutritional requirement in horses. Your horse's body is 70% water and water is essential to all cells in the body.  A 1000-pound horse will drink up to 10 gallons of water a day.  Horses in work will drink up to 20 gallons per day.  In hot, humid climates this number can increase depending on your horse's work load.  Fresh, clean water is a must to keep your horse hydrated.


Energy is found in protein, carbohydrates and fat.  Although protein is a source of energy, it is a poor choice as a source of energy for horses. Horses have to expend energy to convert excess amino acids to energy. However, protein is vital to your horse's health.  It is used to replenish muscle tissue after exercise, grow hooves, hair and generate muscle. Proteins are the main component in living cells, enzymes and many hormones.

Carbohydrates are the main source of energy for horses.  They are found in all forage feed (hay, pasture and plants), in grains and in concentrated feeds.  There are three types of carbohydrates: simple sugars, starches and fibers. Simple sugars are mainly digested and absorbed by the small intestine in the form of glucose. Starches, which are formed by several simple sugars linked together, are broken down in the small intestine mostly in the form of glucose and can be used for fuel immediately, stored as glycogen in the muscle and liver, or stored as fat.  Glycogen is the energy source for aerobic and anaerobic activity.  Fibers are also made up of simple sugars, but they are linked together differently and are fermented in the horse's hindgut as volatile fatty acids.  Fatty acids are also a source of anaerobic energy in horses. Some fibers are indigestible and simply serve to provide bulk in the diet.

Fat is essential in your horse's diet. Just as in people, it packs more calories than carbohydrates and protein – 2.25 times more!!  It can postpone fatigue, prevent colic and is necessary for certain hormone functions. Fats should also be added to your horse's diet when feeding antioxidants.  With the exception of vitamin C, antioxidants are fat soluble and need fat to be absorbed. 


Minerals play many roles in the horse's body.  They are involved in the formation of bone, muscle contraction, energy transfer and some are integral parts of amino acids, vitamins and hormones.  The 7 macrominerals are calcium, phosphorus, potassium, sodium, chloride, magnesium and sulfur. 

Trace Minerals

There are 8 microminerals: cobalt, copper, fluorine, iodine, iron, manganese, selenium and zinc.  Many of the trace minerals have not been studied enough to know what the exact requirements are.  Most of the known trace mineral requirements are readily met in the horse's feed.  The one exception is selenium.

Selenium has been a "hot" topic in the equine nutrition field.  Selenium, in concert with vitamin E, works to remove free radicals and aid in proper muscle development.  Most hays and pastures contain selenium, but in many areas of the Unites States, the soil is deficient in selenium, while in other ares there is a danger of selenium toxicity.  Here in Arizona, the soil is selenium deficient.  Deficiencies can show up in reproductive problems, immune deficiencies and muscle degeneration.  The condition of "tying up" is a classic example of muscle degeneration.  Other symptoms include anemia, lameness, a rough hair coat and brittle ,malformed hooves. Left untreated, it can be fatal.

Having spent 30 years working with horses and consulting several veterinarians on the proper levels, I feed my horses 2mg/day of selenium. 


Pasture forage is a great source of vitamins.  Vitamin requirements are based on age, how hard the horse is working, the health of the digestive tract and whether he/she is used for breeding.  There are two types of vitamins: fat soluble (vitamins A, D, E and K) and water soluble (vitamin C and the B vitamins: thiamin B-1, riboflavin B-2, niacin B-3, panthothenic acid B-5, pyridoxine B-6, biotin B-7, folic acid B-9 and B12).

Vitamins K and C and the B vitamins are all made in the horse's intestinal tract. Most horses on a good-quality hay or pasture with a diet high in fiber can produce these vitamins.  Horses in hard work will benefit from supplementation.  Horses also produce their own supply of vitamin D.  As in people, horses synthesize Vitamin D3 from sunshine!   If your horse spends several hours in the sun, he/she is making enough Vitamin D3. Many of the B vitamins work in concert.  If your horse has a history of colic, ulcers or other health issues that have compromised his intestinal tract, supplementation of these vitamins would be helpful. 

Vitamins A and E need to be supplied in the diet. While both are found in hay and pasture, the vitamin content drops the longer the hay is stored.  Most commercial feeds now add both in small amounts to their feed products, so most horses readily meet these requirements through their feed.

Vitamins A, E and C are the antioxidants of the body.  Antioxidants work to reduce free radicals. Much research has been done on the advantages of supplementing Vitamin E in the horse's diet.  The national requirement for an 1100-pound horse is around 800 IU/day.  It is available in either a synthetic or natural form.  I supplement my horses with 1500 m.g. per day of a natural form of vitamin E.  The benefits of Vitamin C have also been well researched.  Both vitamins E and C are helpful for horses that are in hard work, have joint problems, are under a lot of stress or are older. Vitamin C works best when combined with bioflavinoids. For horses with stomach issues a buffered vitamin C is best.