Electrolytes for Horses

Dr. Judy Reynolds of ADM Alliance Nutrition, Inc. demystifies electrolytes, some of the most necessary--but misunderstood--horse nutrients.
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Electrolytes are probably some of the most misunderstood nutrients. They are a group of minerals, such as sodium, chlorine, potassium, calcium and magnesium. Electrolytes ionize or form a charge in water. They are essential for water and acid-base balance in plants and animals. Calcium and magnesium are also required for many other functions in the body. In most situations, the necessary electrolytes are provided to horses as part of balanced feeding programs.

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Salt, or sodium chloride, is lacking in forages and grains fed to horses, so all horses need salt supplementation. In order to meet the salt needs of horses, most fortified commercial feeds contain between 0.5 and 1.0 percentage salt. It is also common practice to provide a salt or mineral-salt block to horses for free-choice supplementation. However, many horses do not consume enough salt from these blocks alone to meet requirements for sodium and chlorine.

Common grasses and hays contain two to ten times the potassium requirement for horses. And, potassium is 98-100 percentage absorbed in horses. Therefore, horses are constantly removing excess potassium by whatever means are available. In non-sweating horses, the potassium is excreted in the urine. Potassium is also excreted via sweat. When horses sweat, this becomes an additional means to remove EXCESS potassium. Of course, excess potassium does not need to be replaced. Adding more potassium in an electrolyte supplement actually places more stress on the system and can produce detrimental effects such as increased plasma potassium and hyper-excitability.

The other electrolytes are found in varying amounts in normal feeding programs. Therefore, electrolyte supplementation for horses is only necessary in situations where heat and humidity are high and/or horses are working hard. Large amounts of sweat, produced during hard work, are used to cool the horse's body. Most equine electrolytes are formulated to replace lost sweat. Equine sweat generally contains about four parts chlorine to two parts sodium, to one part potassium. Most manufacturers use this formula to create sweat-replacement electrolyte supplements. However, this reasoning is incorrect since, as stated previously, horses typically consume more potassium than they need and sweat helps rid the body of excess potassium. Consequently, adding potassium to an equine electrolyte-replacement product is unfounded.

Another method used to formulate equine electrolytes is to mimic human electrolyte supplements. In nutrition, information from one species is often taken and applied to other species. In some cases, this works very well and is the best method available. In other cases, it is the opposite of what one should be doing. A great example is trying to apply human nutrition concerning electrolytes to horse nutrition.

Electrolytes are only needed to supplement minerals not found in normal diets. And, normal human and horse diets have some very important differences. As a wide generalization, humans are notorious for overeating salt. But, our typical diets generally don't supply enough potassium due to lower intake of fruits and vegetables. Horses are foragers. As stated previously, forages are very rich in potassium, but low in salt. This is because plants use only potassium to maintain their water balance, while animals use both sodium and potassium.

In people and animals, most of the sodium is found in the blood and other extracellular fluids, and most of the potassium is found inside the cells. Carnivores (meat eaters) and omnivores (meat and vegetable eaters) obtain salt from the muscles and tissues of the animals they eat. Herbivores, like horses, get abundant potassium and need to constantly remove it through the urine. Consequently, people and horses have opposite needs for supplemental potassium and sodium.

Supplementing horse diets with an equine electrolyte product is not usually necessary if horses are fed a good, balanced nutrition programs. However, if used, electrolytes for horses should contain sodium chloride, possibly calcium and/or magnesium, and NO potassium. FORAGE FIRST? feeding programs containing GROSTRONG? Minerals for Horses provide all required nutrients including electrolytes.

Horses with the genetic disorder HYPP (Hyperkalemic Periodic Paralysis) are sensitive to ?normal? amounts of potassium in forages and must be provided special low-potassium rations. Horses with HYPP should never be given electrolytes with potassium, as this could cause a lethal reaction.

Electrolytes--The Bottom Line

Begin with a feeding program balanced around good-quality forage.

Supplement nutrients not found in adequate amounts in forages with a Fortified Feed and/or a comprehensive vitamin/mineral product that includes salt, the best of which is GROSTRONG Minerals for Horses.

If additional salt is needed after the maximum amount of GROSTRONG Minerals is fed, use plain, white salt to meet the requirement.

Do not buy electrolyte supplements that contain potassium (read the label). The potassium is not necessary and might be detrimental. These supplements are also a waste of money.

Never give supplements with potassium to horses with HYPP.

For more information about the feeding and care of horses, visit ADM Alliance Nutrition?s online equine library at www.grostrong.com. For free feeding suggestions for your horses, call the Equine Nutrition HELPLINE at 800-680-8254. FORAGE FIRST and GROSTRONG are registered trademarks of Archer Daniels Midland Company.

Reprinted with permission from ADM Alliance Nutrition, Inc., 1000 N 30th St, PO Box C1, Quincy, Illinois, USA 62305-3115; 800-680-8254; www.grostrong.com. Judith A. Reynolds, Ph.D., P.A.S., Dipl. A.C.A.N., is the Equine Nutritionist and Equine Product and Technical Manager for ADM Alliance Nutrition, Inc.