Can a Salt or Mineral Block Meet Your Horse’s Nutritional Requirements?
One of the most common questions horse owners ask is whether providing free-choice access to a plain white salt block or a mineralised salt block is enough to meet their horse’s nutritional needs.
The answer is **it depends**—on the individual horse, its workload, the rest of its diet, and how much of the block it actually consumes.
Will a Salt Block Provide Enough Salt?
For some horses, particularly those at maintenance during cooler months with little or no exercise, a salt block may provide sufficient sodium and chloride when combined with pasture, hay and other feed sources.
However, this varies considerably between horses.
Unlike cattle, horses do not have rough, abrasive tongues designed for efficiently licking hard blocks. While some horses readily consume adequate amounts, others show little interest and may consume very little salt from a block.
For example, a 500 kg horse at maintenance requires approximately **10 g of sodium per day**, equivalent to around **25–30 g of sodium chloride (table salt)** from the total diet. Depending on individual intake, some horses may meet this requirement from a salt block, while others will not.
Once workload increases, salt requirements rise substantially due to sweat losses. Horses undertaking moderate to heavy exercise can require **well over 50 g of salt per day**, making it unlikely they will consume sufficient sodium and chloride from a salt block alone. In these situations, additional salt or electrolyte supplementation within the feed is usually necessary.
What About Mineral Blocks?
This is where many owners are disappointed. Although mineral blocks contain trace minerals, they should not be relied upon as the primary source of mineral nutrition.
Essential trace minerals such as:
* Copper
* Zinc
* Selenium
* Manganese
* Cobalt
* Iodine
must all be supplied in appropriate amounts and, importantly, in the correct balance.
For example, a mature 500 kg horse at maintenance requires approximately **100 mg of copper** and **400 mg of zinc** each day. The concentration of these minerals within many mineral blocks is often too low—and intake too variable—to consistently meet these requirements.
Another consideration is storage. Unlike supplements stored in sealed containers, mineral blocks are continually exposed to sunlight, rain, humidity and environmental contamination, all of which may reduce the stability and availability of some nutrients over time.
Do Horses Prefer Himalayan Salt?
Many owners believe horses prefer Himalayan or pink mineralised salt blocks over plain white salt blocks.
Interestingly, research has not consistently supported this belief.
One study investigating horses’ licking preferences found that horses did **not** spend significantly more time licking Himalayan salt blocks than plain white salt blocks or red mineralised blocks. This challenges the common anecdotal claim that horses naturally consume more Himalayan salt simply because they prefer it.
The pink colour of Himalayan salt comes largely from its iron content. However, iron deficiency is uncommon in horses grazing New Zealand pasture, and additional iron is rarely required.
Plain white salt supplies exactly what horses need—**sodium and chloride**—without unnecessarily increasing iron intake.
The Bottom Line
Free-choice salt blocks certainly have a place in horse management, but they should not be viewed as a guarantee that your horse’s nutritional requirements are being met.
Individual intake varies enormously. Some horses consume very little from a block, while others may consume more than required. Mineral blocks are even less reliable because they rarely provide sufficient trace minerals in the correct quantities or balance to meet individual nutritional requirements.
Rather than relying on trial and error, assess your horse’s complete diet, workload, forage and pasture before deciding what supplementation is appropriate.
Nutrition should always be based on what **your horse actually needs**, not simply what is available in a block.
