Is Your Horse's Diet Really Balanced? What Horses Evolved to Eat
Updated: Jul 17
Have you ever wondered whether your horse's diet is actually balanced?
Most horse owners work hard to provide the best nutrition possible, but modern horse diets often look very different from the varied foraging patterns horses evolved with. Whether horses are fed high-energy competition feeds or spend most of their time grazing improved pasture, dietary variety is often surprisingly limited.
To explore why that matters, imagine three families describing their diets to their doctor.
Family One: High-Energy Processed Diets
“We have a busy lifestyle so we eat quick, high-energy foods. Mostly ready meals. We don’t buy many fruits and vegetables because they spoil too fast. But don’t worry, we take a daily multivitamin.”
This is like the diet of many performance and sports horses. They might have some turnout, often in monoculture ryegrass fields, but most calories come from high-energy processed feeds. These feeds are formulated to provide concentrated energy and nutrients for horses with high workloads. They can play an important role in equine nutrition when used appropriately. However, when large amounts of starch and sugar are fed, particularly where forage intake or dietary diversity is limited, they may contribute to health problems in some horses.
High-starch, high-sugar horse feeds are strongly associated with:
Equine metabolic syndrome (EMS) (Frank et al., 2010)
Obesity (Geor & Harris, 2009)
Laminitis (AAEP, 2023)
Gastric ulcers (Andrews et al., 2015)
Hindgut acidosis (Richards N, 2006)
Like people who rely on processed diets may face higher risks of obesity, diabetes, and heart disease, horses on these diets face long-term welfare challenges.
Family Two: A Grass-Only Diet
“We only eat gem lettuce, iceberg lettuce, red leaf lettuce, tomato, and cucumber. But we’re fine. We take a multivitamin every day.”
This is very similar to the diet of many horses at pasture. UK pastures are often sprayed, fertilised, and overseeded with a handful of grass species, such as ryegrass, fescue, cocksfoot, timothy, and meadow grass (DEFRA, 2019).
When fresh grass runs out, hay is offered, but it’s usually the same limited species, just dried. While hay is often lower in sugar (a good thing), it’s also lower in vitamins and minerals (Harris et al., 2017). Horses are then given a daily balancer or supplement, just like the multivitamin.
Grass provides the foundation of a horse's diet, but many improved pastures contain relatively few plant species compared with natural species-rich grassland. While balancers can help supply essential nutrients, they cannot recreate the botanical diversity that horses would naturally encounter across varied landscapes to support their gut microbiome (Dougal et al., 2014).
Family Three: The Diet Horses Evolved With
“We eat a variety of seasonal fruits and vegetables, cook our own meals, and buy from local farms. We still take multivitamins just in case, but our diet is rich, fresh, and diverse.”
This more closely resembles the type of varied diet horses evolved alongside. Horses in wild, feral or conservation herds forage across diverse landscapes, eating not only grasses but also herbs, shrubs, tree bark, and wildflowers (Duncan, 1992). Their diets are high in fibre, diverse in plant types, and naturally balanced with proteins, fats, vitamins, and minerals.
Unfortunately, very few domestic horses get this kind of variety today.
Why Dietary Variety Matters for Horse Health
Fibre diversity
Different plant species provide different types of fibre, supporting a wider range of hindgut microbes. Less diverse diets have been related to reduced microbial diversity, which may increase risks of colic, ulcers, and metabolic disorders (Dougal et al., 2014).
Plant secondary compounds
Wildflowers, herbs, shrubs and trees naturally contain a wide range of compounds that interact with the gut microbiome and may contribute to health. Fresh forage remains the horses best natural source of Omega-3 (O’Connor et al., 2007) and Vitamin E.
Nutrient diversity
Different plants contribute different amino acids, minerals, vitamins and fatty acids.
Natural behaviour
Horses evolved spending 16–18 hours each day selecting from a wide variety of plants rather than consuming one dominant forage source.
How to Improve Your Horse's Diet Naturally
Provide Turnout: Fresh forage is always best. Let horses graze where safe and appropriate. If your pasture is dominated by ryegrass or a handful of sown grasses, it won’t provide the diversity their digestive system has evolved for.
Increase Woody Fibre: Plant edible hedges and trees for shelter and forage. Or, offer pruned branches like willow in stables and paddocks.
Increase Botanical Diversity: Natural grasslands contain only 60–80% grasses; the rest is herbs and legumes (Hopkins & Wilkins, 2006). Overseeding with a horse-safe wildflower mix, can restore natural diversity to grazing. If you don’t own the land, you can grow in pots or trays of forage herbs that can be moved with your horse. Alternatively, grow in your garden and harvest fresh forage to add to your horses bucket.
Owner of a horse on a livery yard grew the wildflower grazing mix for horses in her garden and pulls it to add to her horses feed.
The Takeaway
Healthy equine nutrition isn't simply about providing enough energy or adding supplements when nutrients may be lacking. It's about understanding the whole grazing system.
Horses evolved alongside diverse grasslands containing grasses, herbs, legumes, shrubs and trees. Modern pasture rarely reflects that complexity, but there are practical ways to move closer to it.
Whether you're managing one pony or an entire herd, increasing botanical diversity alongside good grazing management can help create healthier horses, healthier soils and more resilient pasture.
Learn More About Equine Nutrition and Grazing Management
Our recorded webinar Designing and Managing Pastures for Good Doers explains how horse nutrition, pasture diversity, grazing management and soil health interact, helping you make confident decisions for your own horses.
Or explore our educational courses to learn how to assess your own land and create more resilient grazing systems.
If you're ready to introduce greater botanical diversity, our Wildflower Grazing Mix and Biodiverse Grazing Mix have been developed specifically for horse grazing rather than livestock production.
Frequently Asked Questions
What do horses eat naturally?
Wild and free-living horses don't survive on grass alone. Studies show they eat a wide variety of grasses, herbs, legumes, shrubs and tree material, with the exact mix changing throughout the seasons and depending on what's available. This varied diet provides different fibre types, nutrients and plant compounds while allowing horses to express natural foraging behaviour.
Is grass enough for horses?
Grass forms an important part of a horse's diet, but many modern pastures contain far fewer plant species than natural grazing systems, which are typically at least 20% non-grass species. A species-poor pasture may provide adequate energy and fibre, but it offers less botanical diversity than horses would naturally encounter. Increasing plant diversity can help create a more varied grazing environment alongside good pasture management.
Can supplements replace pasture diversity?
Supplements and balancers are valuable tools for correcting known nutritional deficiencies, but they cannot recreate the wide range of fibres, plant compounds and foraging opportunities found in diverse pasture. Good nutrition is about more than supplying individual nutrients; it also involves supporting natural grazing behaviour and a healthy gut microbiome.
Why is dietary variety important for horses?
Different plants contribute different nutrients, fibre types and naturally occurring plant compounds. A more varied diet also supports natural foraging behaviour and encourages a more diverse hindgut microbiome. While more research is still needed to understand all of these interactions, increasing appropriate pasture diversity is one way of moving closer to the type of grazing system horses evolved with.
Can horses eat herbs and wildflowers?
Many herbs and wildflowers can safely form part of a horse's diet when suitable species are selected. They increase botanical diversity and provide opportunities for more varied foraging. However, not all wild plants are appropriate for horse pasture, so species should always be chosen carefully and pasture managed responsibly.
References
AAEP. “Learn to Recognize the Signs of Laminitis,” AAEP Client Resources PDF. Accessed 2023.
Andrews, F. M., et al. (2015). Gastric ulcers in horses. Equine Veterinary Journal, 47(2), 139–150.
DEFRA (2019). Improving Grassland Management in the UK. Department for Environment, Food & Rural Affairs.
Fernandes KA, Kittelmann S, Rogers CW, Gee EK, Bolwell CF, Bermingham EN, et al. (2014) Faecal Microbiota of Forage-Fed Horses in New Zealand and the Population Dynamics of Microbial Communities following Dietary Change. PLoS ONE 9(11): e112846. https://doi.org/10.1371/journal.pone.0112846
Duncan, P. (1992). Horses and Grasses: The Nutritional Ecology of Equids and Their Impact on the Camargue. Springer.
Frank, N., et al. (2010). Equine metabolic syndrome. Journal of Veterinary Internal Medicine, 24(3), 467–475.
Richards N, Hinch G, Rowe J. The effect of current grain feeding practices on hindgut starch fermentation and acidosis in the Australian racing Thoroughbred. Aust Vet J. 2006 Nov;84(11):402-7. doi: 10.1111/j.1751-0813.2006.00059.x. PMID: 17092327.
Geor, R. J., & Harris, P. A. (2009). Obesity in horses. The Veterinary Clinics of North America: Equine Practice, 25(1), 67–82.
Harris, P. A., Ellis, A. D., Fradinho, M. J., Jansson, A., Julliand, V., Luthersson, N., Santos, A. S., & Vervuert, I. (2017). Feeding conserved forage to horses: recent advances and recommendations. Animal, 11(6), 958–967.
Hoffman, R. M. (2019). Protein in Equine Diets. Kentucky Equine Research.
Hopkins, A., & Wilkins, R. J. (2006). Temperate grassland: key developments in the last century and future perspectives. Journal of Agricultural Science, 144(6), 503–523.
O’Connor, C. I., et al. (2007). Dietary omega-3 fatty acids in horses. Journal of Animal Science, 85(8), 2183–2191.
This is really informative and using the human diet analogy made it more understandable.