Magnesium - Not just for athletes
Horses have a high daily magnesium requirement, which is often underestimated. A blood test is not a reliable indicator for monitoring magnesium intake, as a deficiency in the blood count often only becomes visible when a significant portion (up to a third) of the reserves from the bones has already been released.
Magnesium in the bones plays a role in increasing elasticity and building bone structure. In addition to this structural function, magnesium also acts as an activator for numerous enzymes throughout the metabolism.
Magnesium for horses - The first choice for balanced muscles
Approximately 25–30% of the total magnesium content is found in skeletal muscles. Magnesium is particularly known for its enormous importance in muscle metabolism. It activates the conversion of adenosine triphosphate (ATP) to adenosine diphosphate (ADP), a process that can release previously stored energy from food. Furthermore, it supports the metabolism of carbohydrates, proteins, and fats.
It is easy to understand that the liver is the most important organ for magnesium metabolism, considering this key role. Magnesium is crucial not only for athletes, young and growing horses, pregnant mares, and seniors, but also for horses suffering from, for example, Equine Metabolic Syndrome (EMS). Indirectly, as an activator of glutaminases, it is involved in the detoxification of nitrogen.
However, protein metabolism and the formation of DNA and RNA are also closely linked to magnesium. This shows how fundamentally important magnesium is for muscle building. Magnesium is the key element for relaxed and efficient muscles, whether skeletal, intestinal, or cardiac muscles.
The reasons why magnesium is often considered calming
Magnesium acts as a physiological calcium antagonist and thereby inhibits calcium-dependent excitation processes in the body. The presence of magnesium harmonizes neuromuscular impulse transmission and muscle contractions.
Since magnesium enables neuromuscular coordination and most enzymatic reactions in the muscle, thereby reducing the excitability of muscles and nerves, it is often considered a "calming agent". This effect, of course, only occurs if there was a pre-existing magnesium deficiency that caused restlessness and anxiety.
Why can a magnesium deficiency lead to colic?
A lack of magnesium manifests itself primarily through tension and anxiety. Horses quickly become startled, find touches on their skin unpleasant, and show clumsiness in riding and training. Sometimes, the tension in the muscles can be felt simply by gently stroking the horse's coat.
Even cleaning out the hooves can lead to difficulties. These tensions can also spread to the digestive tract and lead to spasmodic colic.
A magnesium deficiency can even strain the heart, especially - often depending on the weather - and lead to circulatory problems, which in turn can trigger colic.
This is because magnesium regulates the permeability of cell membranes, thus contributing to the maintenance and stabilization of membrane functions. In the event of a magnesium deficiency, the permeability of potassium channels increases, leading to a lack of potassium within the cell, which negatively affects the action potential of cardiac muscle cells.
Another effect on the cardiovascular system is that even minor changes in magnesium status can influence vascular muscle tone and thus arterial blood pressure.
Some horses also have difficulty defecating, or can only do so at small intervals. The droppings of a horse with magnesium deficiency are often very small, dark, and firm. There is also a lack of thirst. After a needs-based and highly available magnesium supplementation, an improvement in the consistency of the horse's droppings can be observed relatively quickly.
How can a horse owner recognize a magnesium deficiency in their horse?
A magnesium deficiency occurs when the demand is not sufficiently covered by feed or when other factors lead to an increased demand. Typical signs of a deficiency include reluctance to work, lethargy, swollen legs, or breathing difficulties up to heaves. Older horses, young horses during acclimatization or shedding, can be particularly affected. In sport horses, heart problems can frequently occur, but these can often be alleviated by administering a high-quality magnesium supplement.
Further information on magnesium deficiency in horses can be found in our article on Magnesium Deficiency in Horses.
How does an increased need for magnesium arise?
There are certain situations where the need for magnesium increases significantly, and magnesium supplements can help horses cope better with the effects of stress. This can be the case, for example, during a stable change, transport, climate changes, or foaling.
When horses are exposed to strong physical or psychological stress, the body releases increased amounts of adrenaline and noradrenaline. This leads to increased fat burning, during which free fatty acids in the blood bind magnesium and excrete it.
Physical exertion can also lead to increased magnesium loss, primarily through sweat. The consequences can be manifold, including increased susceptibility to stress, over-excitability, and tension.
In cases of magnesium deficiency, the kidney can completely reabsorb magnesium, which can lead to problems with the urinary tract in the long term, such as urinary grit or calcium oxalate stones. Therefore, magnesium deficiency can also cause kidney or bladder stones.
Young horses in growth, sport horses, breeding mares, and older horses, who are often more sensitive to weather changes, are particularly at risk of magnesium deficiency.
Good magnesium supply is especially important for older horses, as it becomes more difficult with age to mobilize magnesium from the bones or absorb it from feed. Therefore, adequate magnesium intake in the feed should be ensured to maintain the health and vitality of older horses.
Daily magnesium requirements for horses
The daily magnesium requirement varies depending on the horse's age, weight, and activity level. Here is a rough guideline you could follow:
- Basic requirement: 1.5 g per 100 kg body weight
- Horses in training: 1.9 g - 3 g per 100 kg body weight
- Pregnant mares (last 3 months): 1.6 g - 1.8 g per 100 kg body weight
These are the questions customers ask us about "magnesium requirements in horses"?
- How much magnesium does a horse need daily?
Literature provides varying figures for the magnesium requirement of a large horse, ranging between 10 and 13 grams per day. During lactation, this requirement increases to 18 to 20 grams. This places magnesium requirements quantitatively second only to calcium requirements.
- Can a horse get too much magnesium?
The risk of overdose is very low when additional magnesium is fed. Excess magnesium is quickly excreted in the urine and does not usually accumulate in dangerous amounts in the horse's body. However, administering high doses can lead to diarrhea.
- How much magnesium citrate is suitable for horses?
For a healthy horse, a dosage of 4 to 5 grams per 100 kg body weight has proven effective. A 550 kg horse should therefore receive a heaped tablespoon, which corresponds to approx. 25 g and contains approx. 2,500 mg of magnesium.
- What are the effects of an overdose of mineral feed in horses?
An exception only applies if large quantities of mineralized concentrate feed are used. It is important to ensure that the horse does not consume too much mineral feed, as overfeeding can lead to bone and organ problems as well as other health issues.
- How much mineral feed does a horse need daily?
A horse weighing 500-600 kilograms needs approximately 32.4 grams of calcium, 22.2 grams of phosphorus, and 12.7 grams of magnesium daily. Additionally, about 138 milligrams of copper, 624 milligrams of zinc, and 1.8 milligrams of selenium are needed.
