​Your Horse’s Pasture and Mineral Imbalances: Part Four

​Your Horse’s Pasture and Mineral Imbalances: Part Four

Posted by Placide on 11th Sep 2017

Sodium, potassium, calcium and magnesium are essential minerals in your horse’s diet. However, in New Zealand, our ever-changing climate can create mineral imbalances in your horse’s pasture, most notably in Autumn and Spring.

In our new series, we examine each of these minerals to highlight their importance in your horse’s diet and minimise potential health problems.

For many horse owners, what appears at first glance to be healthy, nutritious pasture, suitable for horses, is actually numerous grass and legume species that are deficient in some minerals and overloaded with others, leading to harmful health consequences.

Unless your pasture is organically farmed and completely free of fertilisers, your pasture will be imbalanced. Most often, Spring and Autumn grasses are high in potassium and low in sodium, and many New Zealand pastures are simply deficient in calcium and magnesium.

In Part One, we started with sodium and in Part Two, we continued with potassium. In Part Three, we explored calcium and now, in our final Part Four, we wrap up our discussion with magnesium.

Your Horse’s Need for Magnesium

Magnesium is one of the most important minerals in your horse’s body. It is stored primarily within the skeleton and also in the muscles, including the heart. Unfortunately, when magnesium is deficient in the diet, your horse’s body is forced to leach this mineral from within their own cells.

At dangerously low levels, body pH drops, as explained in our previous article. In this state of acidosis, your horse’s health is at risk of many problems linked to low magnesium, including reduced insulin response, which can result in:

  • Obesity
  • Insulin resistance
  • Laminitis
  • Cushing’s disease

Spring Grass and Magnesium

In New Zealand, many pastures are already deficient in magnesium. However, in Spring, grass is especially high in glucose and low in minerals, including magnesium. As such, without magnesium supplementation, your horse’s insulin response is impaired, even after eating glucose.

Problems are further worsened in Spring by the presence of oxalate grasses, such as Kikuyu, which have been shown to not only bind sodium and calcium, but magnesium as well - further reducing your horse’s ability to restore levels of magnesium for healthy body function.

Magnesium deficiencies ultimately affect the cell membranes of both nerve and tissue, which are often exhibited by hypersensitive behaviours, such as:

  • Sensitivity to touch or sound
  • Fearful or resistant behaviours
  • Inability to relax physically or mentally
  • Bucking or rearing
  • Spooking or other unexpected behaviours

Horses and Magnesium Supplementation

As explained in our previous article, when supplementing magnesium, calcium and magnesium - two essential electrolytes - must remain in balance. Otherwise, normal muscular function is affected, often leading to:

  • Tying up
  • Muscle cramps
  • Muscle spasticity

However, when choosing the right magnesium supplement for your horse, there are several considerations to take into account, including:

  1. The type of magnesium supplement
  2. The ingredients contained within

1. Type of Magnesium Supplement

Magnesium sulfate - commonly known as epsom salts - is a popular choice of magnesium supplement in New Zealand. However, it can only be fed short-term. With long-term and regular use, epsom salts may cause gastro-intestinal upsets, including diarrhoea.

Instead, Placide M & Ca, is a safe, proven and fast-acting equine calming supplement that is made from organic chelated magnesium. It can be used daily without any side effects to provide your horse with magnesium and calcium.

2. Magnesium Supplement Ingredients

However, for maximum absorption of both magnesium and calcium, boron must also be present. Without boron, up to 40% of calcium and magnesium is lost in urine. Containing boron, Placide M & Ca will restore magnesium and calcium levels in your grass-affected horse in just one week.


Placide is the number one equine calming supplement in New Zealand. Containing organic, chelated magnesium, Placide works to relax muscles, reduce stress and support your horse’s health for improved performance in less than one week. Click here to find out more.

Disclaimer: This article is not intended as veterinary advice. At Placide, we encourage you to make health care decisions for your horse based on your own research and in partnership with a qualified veterinarian.