A cowboy loops his lasso while a herd of cattle look on.

July 27, 2017

By Matt McMillan, Ph.D., Equine Nutritionist, Hi-Pro Feeds

On a weight basis, the horse’s body consists of approximately 60 to 65% water, 30 to 35% of protein, fat, and stored energy sources, and 4% in minerals.  While minerals only makeup a small portion of the overall body composition of the horse, they play a critical role in the daily function of the horse.  Without minerals, life would not be possible.  A few processes that minerals are involved in include: metabolism regulation, energy production, muscle contraction, water balance, bone development and maintenance, enzyme and hormone production, anti-oxidant activity, red blood cell and amino acid synthesis, soft tissue development and maintenance, nerve conduction, blood clotting, synthesis of vitamins, as well as many more.  While minerals can generally be stored in the body, they are constantly being used and therefore must be replenished through the diet.  If minerals are not replenished through the diet, then breakdown of the body is certain.

Most of the body’s minerals are considered macro-minerals, which include:  calcium, phosphorus, sodium, chlorine, potassium, magnesium, and sulfur.  When these minerals are included in the diet, they are generally expressed in percent form.  This is how they will appear on a feed tag.  Micro-minerals or trace minerals include: selenium, iodine, copper, zinc, manganese, iron, and cobalt.  These minerals are reported in parts per million (ppm) which means they are needed in units 10,000 times smaller than those used for macro-minerals. 

Although they are required in much smaller amounts than macro-minerals, they are still equally as important in the body of the horse.  An example of this would be selenium, which is required by the horse but in very small amounts. Without the inclusion of the selenium even in these very small amounts, many anti-oxidant properties in the body could not be performed which could lead to, in certain situations, a condition known as ‘White Muscle Disease’ which can be debilitating especially to the young horse.

There are other trace minerals that may be needed in the horse’s diet such as vanadium, nickel, chromium, tin, fluoride, and silicon, current research has not determined at  what levels.  Therefore, most, if not all horses will receive the proper amount of these micronutrients through naturally occurring amounts found in quality forage and grain sources.

While we know that horses need minerals to sustain life, it is important to note that the ratios of the amounts of minerals included in the diet need to be taken in to consideration. Minerals often influence the absorption, metabolism, and excretion of other minerals as well as other nutrients. Therefore, excesses or deficiencies of certain minerals can alter the requirements of others.  For example, if phosphorus exceeds the amount of calcium in the diet, calcium absorption can be inhibited which can lead to skeletal abnormalities. Other conditions include iodine, which can cause thyroid tissue damage in both deficient and toxic levels.  Further, high levels of manganese can interfere with phosphorus absorption and zinc is thought to interfere with copper absorption. This is why it is important to feed a good quality feed at the recommended rates according to the feed tag as well as providing quality forage sources. 

Proper mineral nutrition in the horse is critical to sustain good, sound, healthy horses no matter the stage of life or level of activity. To select a high quality horse feed that has been balanced by professional equine nutritionists go to our equine products page.