The horse evolved to live in herds on open plains, moving quietly in a group and living on a wide variety of grasses, herbs and plants. Unfortunately this did not prepare him for the pressures of the modern equine life, and it is fair to say that some horses cope better than others. The causes of nervousness and anxiety should always be properly investigated, but if there are no obvious stresses or physical cause it may be that supplemental support is required.
Magnesium is a vitally important element in the body involved in fluid transfer and enzyme reactions. One of magnesium’s key roles is in maintaining healthy muscle contractions, and tension in the muscles can often be attributed to low levels of magnesium in the system. Magnesium is also needed for the maintenance of a healthy nervous system and a good appetite. The stress of regular work and travel increases the likelihood of a horse’s natural magnesium levels being depleted, so the competition horse can often be found to be low. The lactation period for brood mares is also be a time when the magnesium levels may become lower than they should be.
Rapidly growing grass is low in magnesium while being relatively high in potassium which, itself, impairs magnesium uptake in the system. Therefore if your horse is susceptible to "Spring Fever" or he becomes silly during the spring, it may actually be due to a low magnesium in his grazing.
However, magnesium alone is unlikely to be the whole answer. While the wild horse could pick and choose the herbs he required, the modern horse maintained on his limited species pasture and diet, doesn’t have that choice.
