The Difference Between Organic and Inorganic Mineral Supplements for Horses

When it comes to minerals for horses, you often hear the terms 'organic compound' and 'inorganic compound'. That sounds a bit complicated, but what exactly is that? And why is this important when choosing a supplement, balancer or feed for your horse?

8 February '25 - 4 min reading time

The difference between organic and inorganic mineral compounds lies in the chemical structure of the molecules. The atoms of a mineral are always attached to one or more other atoms, in order to form a stable compound and to be given as a powder or liquid to your horse. This connection with other atoms determines whether the mineral is in organic or inorganic form.

Organic mineral compounds

In an organic compound, minerals are bound to carbon-containing molecules, such as amino acids or proteins. An example is zinc methionine, where zinc is bound to the amino acid methionine. Magnesium chelate is also an example of an organic compound.

Inorganic mineral compounds

In an inorganic compound, minerals are bonded to inorganic molecules, such as sulfates, oxides or chlorides. An example is magnesium oxide, where magnesium is bonded to oxygen.

Bioavailability

Whether a mineral (or other nutrient) actually ends up where it is used in the horse's body depends on its bioavailability. This bioavailability is determined by the absorption from the digestive tract to the bloodstream. For most minerals, this is the limiting factor: what happens in the transfer from the intestines to the blood. The digestibility of a supplement therefore often determines the absorption and availability in the cells.

Horses are different

In horses, the absorption is often different (worse) than in other mammals, partly because horses perform a large part of the digestion in the rear part of the intestines (large intestine and appendix), with the help of micro-organisms. An advanced age, bad teeth, pregnancy and lactation and work and sweating can also strongly influence (increase) the mineral requirement of horses. For example, a horse sweats out relatively more minerals than a human. In our case, when we get used to heat and activity, the sweat becomes less salty, in this way we retain the minerals in our blood more easily. This is not the case with horses, they continue to sweat out minerals. This is the reason why electrolytes are often recommended at high temperatures and for horses that work a lot.

Organic or inorganic?

What kind of minerals are best to use in a supplement for horses? To answer that question, it is important to know that:

• Organic minerals are often better absorbed by the horse's body. This means less is wasted and the minerals are used more efficiently.

• Inorganic minerals are usually cheaper and easier to find, but their absorption may be less.

• In general, organic mineral compounds contain fewer mineral atoms than inorganic compounds such as carbonates, chlorides and phosphates.

• In some cases, different minerals are absorbed via the same route. They then compete with each other. This applies, for example, to copper and zinc and to calcium and magnesium. To supplement a deficiency, it can be useful to 'hide' the mineral in an organic compound. These are often absorbed in a different way and thus do not suffer from competition on the common route.

  
  

Calcium and magnesium

Horses do not always absorb minerals well and sometimes need a lot, especially when they are in work, are older, or have a foal at foot. Research has been done on a number of minerals in horses. Calcium is generally absorbed well, in the form of calcium carbonate and calcium chloride. Organic calcium is better absorbed than inorganic calcium. Horses get calcium mainly from roughage such as grass and alfalfa, because these contain forms of calcium that are soluble in water and calcium is mainly absorbed in the small intestine. It is not so much the amount of calcium, but especially the calcium / phosphorus ratio in the roughage that determines whether a horse gets enough calcium, because these minerals are absorbed via the same route. Incidentally, magnesium also goes via this route and can therefore get into trouble if there is a lot of calcium in the ration. The ideal ratio between the three is 2:1:1 (calcium / phosphorus / magnesium).

Also good to know: Phytate/phytic acid from wheat can limit calcium absorption, which is one of the reasons why feeding (large amounts of) grain to horses is often discouraged. Magnesium is easily absorbed from chelate and sulphate. Magnesium oxide is not as easily absorbed, but is much cheaper. It is often recommended to feed a combination of organic and inorganic minerals, so that you benefit from the advantages of both. It is also advisable to consult with a veterinarian or nutritionist to put together a balanced diet for your horse.