Salt, Minerals and the Land: What Wild Horses Teach Us About Nutrition and Pasture Health

Salt is essential to horses. Sodium supports nerve function, muscle contraction, hydration, and temperature regulation. In domestic settings this often translates to buckets, blocks, and supplements (Schryver et al., 2025; Clegg & McBride, 1987). But wild and feral horses manage to meet their mineral needs without human input.

The reason is not resilience or luck. It is access to functioning landscapes.

How wild and feral horses obtain salt and minerals

Wild and feral horses live within mineral systems, not managed paddocks. Their nutrition comes from the land as a whole, not from a single forage source. Many populations regularly visit natural salt licks or exposed mineral rocks. These may be inland deposits, eroded cliff faces, dried lake beds, or naturally saline soils. Horses will travel long distances to access them, often returning to the same sites year after year (Tankersley et al., 2004; Journal of Mammalogy, 2008). These locations provide sodium alongside other trace minerals that work together in balance.

The Camargue, a wetland in Southern France where the Rhône River meets the Mediterranean Sea, famous for its wild landscapes and semi-domesticated white horses. It's a protected natural park, known for its salt production and distinct culture. 

In coastal regions, salt is consumed indirectly through sea spray on grasses, herbs, and shrubs. Even small amounts of salt deposited on plant surfaces contribute to daily intake when horses are grazing for many hours across large areas (Scasta et al., 2016).

Minerals are also obtained through diverse forage. Wild horses consume a wide range of grasses, forbs, herbs, shrubs, tree leaves, bark, and roots. Many of these plants draw minerals from deeper soil layers that cultivated grasses cannot reach. Small amounts of soil are naturally ingested during grazing, particularly in dry conditions or when grazing close to the ground, adding further trace minerals (Muskwa-Kechika Research, 2004).

Movement is critical. Wild horses walk many kilometres each day, grazing continuously and sweating in small, steady amounts. Mineral intake and loss remain in balance because both are spread across time and terrain (Scasta et al., 2016).

It's also important to remember that wild horses are not eating a "perfect" diet. They experience seasonal shortages, changing forage quality and environmental extremes. The difference is that they usually have access to a much wider range of plants, soils and landscapes over time, allowing nutritional variation that most domestic horses never experience.

Why domestic horses often appear salt deficient

Domestic horses rarely require salt because they are inherently different from wild horses. They require it because the environments we manage are fundamentally different from the landscapes horses evolved within.

Most horse pastures in the UK are dominated by a small number of cultivated grass species bred for productivity rather than nutrition. These grasses are typically high in potassium and sugars, and very low in sodium, magnesium, and trace minerals. Improved pasture is often naturally high in potassium relative to sodium. High dietary potassium can increase sodium excretion, meaning domestic horses frequently need additional salt compared with horses foraging across more diverse landscapes.

Add restricted movement, intermittent exercise, conserved forage, and low mineral water supplies, and supplementation becomes necessary. Salt is then used to compensate for what the land no longer provides. This is why many horses appear drawn to salt blocks. They are not necessarily mimicking wild behaviour, they are responding to imbalance (Schryver et al., 2025).

How the grazing system influences mineral balance

Simplified pasture

One or two productive grass species → Limited dietary choice → Greater reliance on supplements → Higher management inputs

Species-diverse pasture

A wider range of grasses, herbs and wildflowers → Greater dietary diversity → The land supports more of the horse's nutritional needs  → Supplementation still has a role, but becomes a much smaller part to play.

The hidden cost of monoculture grass swards

Uniform grassland does more than limit mineral intake. It removes choice.

Horses appear capable of selecting from diverse plant communities in ways that help balance aspects of their nutrition, although this ability has limits and depends on the choices available. In a pasture dominated by one or two grass species, those choices become far more limited, making it harder for horses to express natural foraging behaviour and increasing the likelihood that nutritional gaps will need to be filled through management (Dumont et al., 2006).

High-sugar grasses, such as perennial ryegrass, can lead to higher insulin responses in susceptible horses. Elevated insulin also influences how the kidneys handle electrolytes and may contribute to increased sodium losses. Combined with limited plant diversity, this can increase reliance on salt supplementation while also contributing to metabolic challenges in horses predisposed to conditions such as equine metabolic syndrome (EMS) and laminitis. The cycle doesn't stop there.

Adding a salt block like the one pictured above can help if salt is needed in the horses diet, but alone, it will not prevent minerla imbalances

Mineral depletion drives appetite and cravings, so horses eat more, usually from the same high-sugar sward. More sugar leads to more insulin, more mineral loss, and more thirst. Over time, this vicious circle increases the risk of weight gain, metabolic stress, and laminitis, particularly in easy keepers, native breeds, and horses prone to sugar-sensitive conditions.

Providing extra salt alone does not break this cycle. The root cause is the uniform, sugar-rich pasture. Diversifying swards with low-sugar grasses, herbs, and wildflowers restores choice, supports mineral balance, stabilises energy, and lets horses self-regulate naturally, just like wild and feral horses do when they forage a variety of plants and lick mineral-rich rocks (Moinardeau et al., 2025).

Can More Diverse Pasture Reduce Reliance on Supplements?

Introducing a wider range of safe grasses, wildflowers, herbs, and forbs changes how horses interact with their environment.

Diverse swards provide small but meaningful amounts of sodium and trace minerals. More importantly, they supply the minerals that support absorption and retention, reducing losses rather than constantly trying to replace them (Scasta et al., 2016).

Deep rooted plants access nutrients beyond the reach of ryegrass. Forbs and herbs support gut health, improving mineral uptake. Structural diversity slows intake, stabilises insulin responses, and reduces the metabolic demand for supplementation (Moinardeau et al., 2025).

Species diverse swards are more likely to support horses with a balanced diet.

Horses grazing diverse pasture often show calmer salt consumption. They still use salt when needed, particularly during work or heat, but the urgency reduces. The land begins to share the nutritional workload. Note that some horses, particularly those with metabolic issues will still need careful management.

Ecological pasture management aims to reduce unnecessary dependence on external inputs where appropriate, not eliminate evidence based supplementation when horses need it.

Learning from wild systems without copying them

We are not trying to turn horse paddocks into wilderness, nor remove salt provision altogether. Wild systems offer principles, not templates.

The principle is this: When land functions more like a healthy ecosystem, it can support more of the horse's nutritional and behavioural needs (Scasta et al., 2016).

Salt supplementation remains good practice in domestic management, especially for working horses. But it works best when paired with land that supports mineral balance rather than undermines it. Monoculture grass creates dependence. Diverse pasture creates resilience (Moinardeau et al., 2025).

By restoring plant diversity through thoughtful seed selection, soil care, and grazing management, we move closer to a system where horses can regulate themselves more effectively, management inputs and costs can reduce over time, and the land becomes healthier rather than harder to manage. Healthy soil grows diverse plants. Diverse plants support balanced nutrition. Balanced nutrition supports horse welfare.

That is not a trend. It is how horses evolved to live.

Frequently Asked Questions

Why don't wild horses need salt blocks?

Wild and feral horses don't usually need manufactured salt blocks because they live within functioning landscapes that provide multiple natural sources of sodium and other minerals. They may visit natural salt licks, consume plants growing on mineral-rich soils, graze a much wider variety of species, and travel across large areas throughout the year.

Is a salt lick enough for domestic horses?

A salt lick or salt block provides an important source of sodium, but it isn't designed to supply every mineral a horse needs. Horses also require a balanced intake of minerals such as calcium, phosphorus, magnesium, copper, zinc and selenium, which depend on forage, soil conditions, workload and individual requirements. Salt should therefore be viewed as one part of an overall nutrition plan rather than a complete mineral solution.

Can improving pasture reduce mineral deficiencies?

Improving pasture diversity can help create a more balanced grazing environment by providing horses with a wider variety of plants and naturally occurring nutrients. Diverse pasture may support mineral intake, encourage more natural foraging behaviour and reduce reliance on some management inputs over time. However, no pasture can guarantee that every horse's nutritional requirements will be met.

Soil type, forage quality, workload, health status and environmental conditions all influence mineral intake. Appropriate supplementation should always be based on the individual horse and, where possible, forage analysis and professional nutritional advice.

Can improving pasture replace mineral supplements?

Not completely. Most domestic horses will still benefit from appropriate mineral supplementation depending on their forage, workload, health and management. Ecological pasture management isn't about eliminating supplements. It's about creating grazing systems that naturally support more of the horse's nutritional needs, reducing unnecessary dependence on external inputs where appropriate.

References

1. Schryver, H., et al. (2025). Effect of form on equine salt intake. Journal of Equine Veterinary Science. https://www.sciencedirect.com/science/article/pii/S0737080625001601

2. Clegg, F. M., & McBride, B. W. (1987). Voluntary salt consumption in horses. PubMed.https://pubmed.ncbi.nlm.nih.gov/3568683/

3. Tankersley, R., et al. (2004). Importance of natural mineral licks to ungulates. Alaska Department of Fish & Game. https://www.adfg.alaska.gov/static/home/library/pdfs/wildlife/research_pdfs/importance_natural_mineral_licks_ungulates.pdf

4. Journal of Mammalogy (2008). Field studies of ungulates’ use of mineral licks. https://academic.oup.com/jmammal/article/89/4/1041/867975

5. Scasta, J. D., et al. (2016). Wild and feral horse foraging ecology and nutrient intake. https://www.sciencedirect.com/science/article/abs/pii/S1550742416000038

6. Muskwa-Kechika Research (2004). Mineral access from soil and plant sources in wild herbivores. https://muskwa-kechika.com/uploads/_research_unbc/Mineral_Licks_report_July_2004.pdf

7. NRC (2007). Nutrient Requirements of Horses, 6th Revised Edition. National Academies Press. https://www.nap.edu/catalog/11653/nutrient-requirements-of-horses-sixth-revised-edition

8. Dumont, B., et al. (2006). How do horses graze pastures and affect the diversity of grassland ecosystems? ResearchGate. https://www.researchgate.net/profile/Bertrand-Dumont/publication/258243497_How_do_horses_graze_pastures_and_affect_the_diversity_of_grassland_ecosystems/links/603e4aa04585154e8c70a3fe/How-do-horses-graze-pastures-and-affect-the-diversity-of-grassland-ecosystems.pdf

9. Frank, N., et al. (2010). Effects of high-sugar grasses on mineral loss and insulin response in horses. PubMed. https://pubmed.ncbi.nlm.nih.gov/20612980/

10. Moinardeau, M., et al. (2025). Pasture diversity and its effects on equine mineral intake and metabolic health. Animals (Basel), 15(6), 862. https://www.mdpi.com/2076-2615/15/6/862