Minerals are inorganic substances that must be consumed in small amounts -- usually only milligrams or grams a day -- but still play a very important role in the equine body.

Minerals are important to your horse.

Almost everything your horse does is going to require them to some extent. They are important in a number of physiological functions:

  • acid-base balance
  • enzyme function
  • energy transfer

They are also important in most structural components of the horse's body...one of the most well-known one being calcium in bones.

The are also parts of vitamins, hormones, and amino acids.

Not only are individual minerals important, but so are the ratios in comparison to each other. The most well-known ratio in the horse diet is the calcium:phosphorus ratio, but there are other important ratios as well.

These ratios are so important because the concentration of one mineral will exert influence over the absorption, metabolism, and use of other minerals, vitamins, and nutrients.

They are classified into two groups based on how much your horse needs:

  • Macrominerals
  • Microminerals

Now, lets take a look at these two groups (as well as some extras that are not classified) and see which ones belong in each category...


Macrominerals are those that your horse needs in a larger amount, relative to others.

Macrominerals include:

Usually macrominerals will be needed in a certain number of grams per day...

...however, don't be confused by amounts that are listed mg/kg body weight. Since most horses weigh around 500 kg (1100 lbs), the mg are multiplied by 500, which will give you a large number of mg which can then be converted into g.

For example, horses need 80 mg chlorine/kg BW each day.

80 mg x 500 = 40,000 mg each day

40,000 mg / 1000 = 40 g needed each day

The table below shows the daily intake recommendations of the macrominerals for an adult horse (500 kg) at maintenance level. This will give you an idea of about how much of each macromineral is needed.

Macromineral Recommendation
Calcium 21g
Chlorine 80 mg per kg BW
Magnesium 15 mg/kg body weight
Phosphorus 14 g/day
Potassium 0.05 g/kg body weight
Sodium 0.02 g/kg body weight
Sulfur 0.15% of dry matter intake


Microminerals are those that are needed in smaller amounts than the macrominerals. These are often only required in mg/day as opposed to g/day.

Microminerals include:

Below is a table that shows the daily intake requirements for an adult horse (500 kg) at maintenance level.

Micromineral Recommendation
Cobalt 0.05 mg/kg dry matter intake
Copper 10 mg/kg dry matter intake
Iodine 0.007 mg/kg body weight
Iron 40 mg/kg dry matter intake
Manganese 40 mg/kg dry matter intake
Selenium 0.1 mg/kg feed intake
Zinc 40 mg/kg dry matter intake


There are a few other minerals that are of interest in the equine diet because of their importance in the body. These are not classified as either macro- or microminerals.

They have not been studied enough in the equine body to know if there is a required dietary intake. It appears that these minerals are consumed in adequate amounts in an average equine diet.

These others are:

  • Chromium
  • Flourine
  • Silicon

Overall, more research needs to be done on these before recommendations about intake can be made.

Ratios of Importance

We've covered the fact that it is important for your horse to get a certain level of minerals in his diet daily. However, there are some that must also be consumed in a ratio to others. In some cases, these ratios may be even more important to your horse's health than the actual intake amounts!

Here are the important intake ratios you should know about and be aware of:

Minerals, though needed in very small amounts, are essential to your horse's health.

Knowledge of these inorganic substances is just one more important part of horse nutrition.

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