Kentucky Performance Products: Horses & Iron

Here’s the 411 on this important and readily available trace mineral.


From the KPP Tips & Topics Blog:

Iron is considered a true trace mineral. Its main role is to assist in the transportation of oxygen throughout the horse’s body. Iron is required for the synthesis of hemoglobin. Hemoglobin is the pigment found in the red blood cells responsible for picking up oxygen from the capillaries in the lungs and transporting it to other body tissues. Sixty percent of the iron in a horse’s body is involved in oxygen transportation.

It is a common misconception that iron is associated with low energy levels and anemia in horses. In fact, anemia is defined by a reduction of red blood cell mass, not a lack of iron. There is no research supporting iron supplementation to increase athletic ability or daily energy levels.

Iron is measured in an expression of concentration noted as parts per million (ppm). Your horse only needs to consume a small amount of iron daily. The great majority of horses consume adequate iron in their normal diet. Iron is most efficiently absorbed at low levels of intake. Iron absorption decreases as iron consumption increases; however, you can feed too much iron.

Iron requirements for horses:

  • 40 ppm per day for mature equines
  • 50 ppm per day for pregnant or lactating mares
  • 50 ppm per day for growing horses

A small amount of iron is lost in sweat. Intensely exercised horses that sweat a lot might have higher requirements than sedentary horses.

Sources of iron:

Iron can be found in a wide range of equine feedstuffs as well as in the soil. Forages contain between 200-1,000 ppm iron; grains range between 40-50 ppm; and oilseed meals contain 100-150 ppm. The iron levels in the soil vary depending on soil pH and the presence of other minerals. Soil has been shown to be a significant source of iron for horses. Horses grazing on pasture rarely show iron deficiencies.

Toxicity is more of a problem than deficiency

In the horse, iron toxicosis is a much more common problem than iron deficiency. The horse is very efficient at recycling iron; therefore, there is almost never a net loss of iron from the body of a healthy horse. Horses have no way of excreting excess iron; instead they protect themselves from accumulating excess iron by reducing absorption in the GI tract. Injecting iron bypasses this natural safety measure and increases the risk of developing iron toxicosis.

Consequences of toxicosis

  • Increase risk of bacterial infections
  • Disruption of proper copper metabolism
  • Liver damage in foals

Iron deficiency is a rare occurrence in horses

Iron deficiencies are rare and when they do exist are most commonly caused by blood loss due to severe ulceration, parasite damage, or traumatic injury.

Measuring blood transferrin (iron transport and storage protein) is the best way to test for iron deficiencies. Iron supplementation has not been scientifically proven to increase hemoglobin, packed cell volume, or serum iron. Never supplement with iron without first consulting your veterinarian and testing your horse’s iron levels.


Article written by KPP staff.

Copyright (C) 2015 Kentucky Performance Products, LLC.   All rights reserved.

Article sponsored by Micro-Phase, which provides essential vitamins and trace minerals missing from forages and unfortified diets in an easy-to-digest form.

When health issues arise, always seek the advice of a licensed veterinarian who can help you choose the correct course of action for your horse. Supplements are intended to maintain healthy systems and support recovery and healing. They are not intended to treat or cure illness or injury.

thumb.phpAbout Kentucky Performance Products, LLC: Since 1998, Kentucky Performance Products has simplified a horse owner’s search for research-proven nutritional horse supplements that meet the challenges facing modern horses. KPP horse supplements target specific nutritional needs and are formulated to complement today’s feeds, thus safeguarding against over-supplementation. Each product is scientifically formulated and made with high-quality ingredients at certified manufacturing facilities. Kentucky Performance Products is proud to offer a quality assurance promise backed by a money-back guarantee. Kentucky Performance Products brings you horse supplements you can count on because the horse that matters to you, matters to us.

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