Magnesium – The Mineral Superstar!
If you recall from last month, we started to cover magnesium and its important roles in your horses diet. We discussed how magnesium affects your horses blood, bones, liver and nervous system. In this blog, we will take an in depth look at magnesium deficiency and how it can affect your performance horse.
What contributes to magnesium deficiency?
STRESS and stress hormones adrenalin, noradrenalin and cortisol- Cortisol is released by the adrenal glands. It is responsible for the ‘fight or flight’ response to stress.
(Example-race horses- they are frequently supplemented with calcium to increase bone density and for calming) This can actually do the opposite as it inhibits the body’s absorption of magnesium, therefore the body pulls magnesium from the muscles and bones to keep the magnesium level constant in the blood.
Approximately 60 percent of the body’s magnesium is in the skeleton, 39 percent is inside cells(20 percent in skeletal muscle), and less than 1 percent outside the cells (mainly in the bloodstream) This makes testing for magnesium levels in the blood inconclusive because the body will work hard to maintain the proper amount of magnesium in the bloodstream.
Mares can pass on a deficiency to their foals in turn passing on the behavior associated with a short fall of magnesium.
Horses with a magnesium shortfall often crave excessive amounts of salt, increasing urine output therefore increasing the amount of magnesium excreted.
How much to feed each day?
IF your horse is showing signs of deficiency, Horses in heavy training have a much higher daily requirement, often double that of a non working horse. What kind of magnesium should I use? There are injectables, oral supplements and trans dermal applications. The most popular is oral magnesium oxide. It is not the most bio-available form of magnesium to use but it is the most available and inexpensive to feed. Some horses do not like the powdery texture so picky eaters may turn up their noses to it. It can also act as a buffer in the horse’s stomach which can help horses who tend to develop ulcers. There are many oral forms of magnesium; the best form of which is Di-magnesium malate or chelated magnesium. It is highly absorb-able, bio-available and has the least potential laxative effect. Horse owners need to be aware that magnesium is in different forms such as citrate, oxide, ascorbate, which is the secondary ion. Horse owners should avoid magnesium sulfate because of its laxative effect. If you are giving 20 grams of magnesium oxide, approx 10 grams are actually magnesium and of those 10 grams, studies range from only 20% to 50% or 2 to 5 grams absorption.
One has to feed a seemingly large volume to attain the desired dosing. We recommend feeding 20 to 30 grams daily or up to bowel tolerance, for working horses exhibiting mild to moderate signs of magnesium deficiency. Horses showing severe signs of deficiency respond well to 20 grams, twice daily for up to 2 weeks, then taper the dosage off according to the horse’s level of improvement. Every horse is different and will have its own individual maintenance dose. This will also fluctuate depending on times of stress, showing, weather and pasture content. When signs of deficiency begin to subside, the dosage can be tapered off to 15.5 grams daily.