Morgan Murphy

Magnesium – Calming the Excitable horse 


Many horse owners and riders understand the frustration of dealing with overexcited horses! Whether you are at a show and he bucks during his dressage test, or you are trying to catch him from the field and he gallops off in the other direction, horses can become excitable for different reasons. At this time of year, spring grass and the high sugar content can send your horse a little crazy, similarly getting out and about to shows can present new sites and sounds which can challenge even the quietest horse. It isn’t just seasonal though – extended indoor periods during winter can lead to the horse experiencing excessive energy and being overly excitable. Even changes in routine, new barn mates or new owners can make a horse "act out."

The horse has a natural flight instinct which makes him excitable*

Various supplements have been recommended to help calm horses but until now, much of the evidence presented in their favor was purely anecdotal. However, a new study suggests that the addition of magnesium to the diet can help calm excitable horses.

It’s all in the tub!

Horse owners have long purchased calming supplements containing magnesium sulfate and magnesium oxide hoping for an improvement in their horse’s behaviour. Until recently, magnesium aspartate wasn’t commonly used. Each chelate – this means the oxide, sulfate or aspartate – of magnesium has a different absorption rate or "bioavailability" and in turn, effect on the horse.

Bioavailability refers to how much of the magnesium is available for use by the body and how easily this can be metabolized .

Magnesium oxide contains a high level of magnesium, but poor levels of bioavailability (only 4%.) Magnesium sulfate is an inorganic form of magnesium with an elemental concentration of 10% and lower levels of bioavailability. Magnesium Aspartate has a higher level of bioavailablity compared to any of the other chelates.

Investigating the science

A study into the effects of magnesium aspartate supplementation was conducted at Charles Sturt University in New South Wales, Australia, in collaboration the WALTHAM Equine Studies Group. The team studied the reaction speeds of six Standardbred geldings.

The study involved adding 10 grams of magnesium aspartate to the horses diets. Each horse was monitored to ensure they were already receiving the recommended daily amount of magnesium through their nutrient rich forage. Their diet consisted of clover and ryegrass hay fed throughout the day, ad lib. The results demonstrated that with the additional 10 grams, the flight reaction speed of each horse was reduced by an average of 1/3rd. Without the supplement, the horses averaged 5.3 meters per second, with the supplement, they slowed to 3.1 meters per second.

Changing Supplements?

When we look at supplements currently available on the market, most contain magnesium in its sulfate and oxide forms. The results of this study give a promising indication that the use of magnesium aspartate as an ingredient in horse feed and supplements could help to encourage calm, quiet behavior in excitable horses. In this more bioavailable form, it could be included as part of a complete feed or as an oral supplement. However, as this study was done using only 6 horses, more research and further investigation should be imminent.

 *Image courtesy of Dollar Photo Club