Move over, alfalfa. There’s a new legume in town — and it’s not just another pretty pink flower. Sainfoin hay (Onobrychis viciifolia) is making a comeback in equine nutrition for good reason.
Once called “holy hay” by 16th-century horsemen, sainfoin was prized for its digestibility, palatability, and health-promoting properties long before bagged feeds and synthetic dewormers took over the feed room. And now? Modern research is backing up what those old-school graziers knew all along.
What Exactly Is Sainfoin?
ainfoin (Onobrychis viciifolia) is a perennial legume — like alfalfa. It thrives in dry climates, fixes nitrogen into the soil, and doesn’t cause bloat (a rare superpower for a legume).
Historically, sainfoin was a staple in European horse diets for centuries. King Henry VIII even sent botanists to France to bring it back to England in the 1500s. So why did it disappear? Industrial farming favored faster-growing crops like alfalfa and soy.
But sainfoin is making a quiet comeback
Nutritional Profile of Sainfoin Hay
Horses love sainfoin. Studies report voluntary intake up to 30% higher than other hays, including alfalfa. Not only is sainfoin highly palatable, but this exciting and lesser-known crop has very high nutritional value.
- More digestible
Unlike many rich legumes, sainfoin is non-gas-producing, making it a safer option for horses prone to bloating, gas colic, fecal water syndrome, or hindgut acidosis. Its high fiber content encourages longer chewing, which boosts saliva production and supports acid regulation in the stomach. That alone makes it ulcer-friendly — and easier on the hindgut than many commercial feeds.
- High-quality protein
With highly digestible protein (~76%) and a full amino acid profile, sainfoin helps maintain muscle mass and topline — especially in senior horses or those recovering from illness or work. Thanks to its tannin-bound “bypass protein,” more amino acids actually reach the hindgut for absorption, improving efficiency over hay with similar crude protein but lower bioavailability.
- Low sugar and starch
One of sainfoin’s biggest advantages? It’s naturally low in non-structural carbohydrates (NSC) — meaning it won’t spike blood sugar or insulin levels the way alfalfa, ryegrass, or many commercial hays can.
- Deworming Support (Backed by Emerging Research)
Studies in ruminants — and early trials in horses — suggest sainfoin’s tannins may reduce internal parasite load. Horses fed ~1.7 kg/day of sainfoin showed lower fecal egg counts and less motile parasite larvae, which may reduce pasture contamination. While not a replacement for targeted deworming, it’s promising as a natural support strategy.
- Rich in Omega-3s
Sainfoin is naturally rich in omega-3 fatty acids and plant polyphenols, including condensed tannins, which have been shown to support a healthy inflammatory response. These compounds don’t act like NSAIDs — they’re not instant fixes — but they do contribute to overall immune modulation and cellular repair when part of a consistent forage-based diet.
- Balanced minerals
Sainfoin offers a more balanced calcium-to-phosphorus ratio than alfalfa — typically closer to 2:1, instead of alfalfa’s often extreme 5:1 or higher. Why does this matter?
Because too much calcium, especially when unbalanced with phosphorus, interferes with magnesium, zinc, and copper absorption — critical trace minerals for hoof health, hormone balance, and immune function.
Unlike alfalfa, sainfoin contains condensed tannins that protect protein from breaking down too early in digestion — allowing more to reach the hindgut where horses actually absorb it. This “bypass protein” effect means better nutrient utilization with less metabolic strain.
Is Sainfoin Hay Right for Your Horse?
If you’re feeding an easy keeper, a metabolically challenged horse, or one with digestive quirks — sainfoin deserves a spot on your radar. Here’s who benefits most:
Ideal For:
- Metabolic horses (EMS, PPID, insulin-resistant)
- Horses prone to colic, gas, fecal water, or ulcers
- Senior horses who need soft, palatable forage
- Picky eaters or horses coming off illness
- Horses needing topline or protein support — without the sugar or mineral imbalances of alfalfa
Considerations:
- Availability is still limited, though it’s growing in the U.S. and Europe.
- Cost per bale may be slightly higher than alfalfa — but you’ll waste less thanks to its high palatability.
- For large herds, sourcing enough sainfoin to be the only forage might be tricky — but it works beautifully as a partial hay replacement or top-up.
Even mixing in sainfoin pellets can provide the gut and protein support benefits, especially during travel, stress, or seasonal transition.
Where to Buy Sainfoin
Sainfoin hay and pellets are still niche — but demand is growing fast, and supply is catching up.
Buying Sainfoin
- In North America, StableFeed is currently the primary producer offering sainfoin-based products for horses, including:
- Sainfoin Forage Pellets
- Seasons Biome Blend Feed (includes sainfoin + other forage ingredients)
Made with a sainfoin base with organic chia seeds, soybean meal, organic wheat grass powder, organic carrot meal, brewer's yeast and minerals and vitamins. This is a great idea to support your horses gut microbiome and deliver proper nutrition with changing formulas throughout the year to provide diversity.
Each 40lb bag contains 100% premium sainfoin with no harmful binding agents or preservatives.
- Low sugar and starch
- Highly palatable
- High fiber to increase chewing and salivation
- High Omega 3's
- Non-gas producing
- Some local hay growers, especially in the Western U.S. and Europe, are beginning to experiment with sainfoin fields. Ask your hay supplier!
Growing It Yourself
If you’re a small-scale hay producer or landowner:
- Sainfoin is drought-tolerant, deep-rooted, and non-GMO
- Acts as a nitrogen-fixing crop, improving soil fertility without synthetic fertilizer
- Bee- and wildlife-friendly, with vibrant pink flowers that support pollinators
- Doesn’t cause bloat — so it can be safely grazed
Growing tips:
- Prefers pH > 7 and well-drained soils
- Needs a little patience: slower to establish than alfalfa and sensitive to overgrazing early on
- Works best in drier, cooler climates (e.g. U.S. West, Canada, parts of Europe)
Sainfoin isn’t some trendy new supplement — it’s an old-school, field-tested forage that modern horses still benefit from today. It supports digestion, offers clean, bioavailable protein, and brings natural anti-inflammatory and anti-parasitic properties to the table. And unlike alfalfa, it does all that without tipping metabolic horses over the edge.
Yes, it can be a little harder to source. Yes, it might cost a bit more up front. But when your horse actually eats it, the math starts to make sense.
Whether you’re managing laminitis risk, supporting a senior, or just want a better legume in your hay barn, sainfoin is absolutely worth considering.
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References
- Ellwood, Charles. “Reviving Sainfoin in the Midwest and Greater United States.” StableFeed, 2025, stablefeed.com/blogs/learn/reviving-sainfoin-in-the-midwest-and-greater-united-states?srsltid=AfmBOorIuuCjF7aJr_vY-sci1YOMbRu0h9evdCpldfpphOc4HBwxW_lw. Accessed 24 July 2025.
- Grimm, Pauline, et al. “Inclusion of Sainfoin in the Diet Might Alter Strongyle Infection in Naturally Infected Horses.” Animals, vol. 12, no. 8, 7 Apr. 2022, p. 955, https://doi.org/10.3390/ani12080955.
- Hayot Carbonero, Christine, et al. “Sainfoin ( Onobrychis Viciifolia): A Beneficial Forage Legume.” Plant Genetic Resources, vol. 9, no. 01, 4 Mar. 2011, pp. 70–85, https://doi.org/10.1017/s1479262110000328. Accessed 29 Mar. 2021.
- Meccage, Emily. “What’s the Deal with Sainfoin? – MSU Extenison Animal and Range Science | Montana State University.” Montana.edu, 2025, animalrangeextension.montana.edu/forage/sainfoin_deal_MT.html. Accessed 24 July 2025.
- The Cheshire Horse. “Holy Hay: Reintroducing Sainfoin Forage – the Cheshire Horse.” Cheshirehorse.com, 9 Feb. 2023, blog.cheshirehorse.com/2023/02/09/holy-hay-reintroducing-sainfoin-forage/. Accessed 24 July 2025.