Grass Types & Their Nutritional Value for Horses

Why Grass Type Matters for Your Horse

Grass is the foundation of most horses' diets. In the wild, horses evolved to graze on a wide variety of grasses across vast landscapes, naturally balancing their nutrient intake as they moved. Today, most domestic horses graze on managed pastures — and the type of grass growing in those pastures has a huge impact on their health, weight, and performance.

Understanding grass types and their nutritional value for horses isn't just an academic exercise. It can help you prevent obesity, manage laminitis risk, address mineral deficiencies, and ensure your horse gets the right balance of energy and fibre. Whether you're establishing new pasture, overseeding existing fields, or simply trying to understand what your horse is actually eating, this guide will help.

Cool-Season vs Warm-Season Grasses

Before diving into specific species, it helps to understand the two broad categories of pasture grasses.

Cool-Season Grasses

These grasses thrive in temperate climates with moderate temperatures (15–24°C / 60–75°F). They grow most vigorously in spring and autumn, and their growth slows or goes dormant during hot summers. Cool-season grasses are the dominant pasture types across the UK, Ireland, northern Europe, and cooler regions of North America and Australia.

Examples include perennial ryegrass, timothy, orchardgrass (cocksfoot), tall fescue, and meadow fescue.

Cool-season grasses tend to be higher in non-structural carbohydrates (NSC) — the sugars, starches, and fructans that can be problematic for horses prone to laminitis, insulin resistance, or equine metabolic syndrome.

Warm-Season Grasses

These grasses perform best in hotter climates (above 27°C / 80°F) and are common in the southern United States, tropical regions, and parts of Australia. They grow actively during summer and go dormant in cooler months.

Examples include bermudagrass, bahiagrass, and teff grass.

Warm-season grasses generally have lower NSC levels but can be higher in fibre and lower in overall digestibility. This makes them a safer option for metabolically challenged horses but potentially less energy-dense for horses in hard work.

Common Cool-Season Grasses for Horses

Perennial Ryegrass (*Lolium perenne*)

Perennial ryegrass is one of the most widely sown pasture grasses in the UK and Ireland. It establishes quickly, is highly productive, and tolerates heavy grazing.

Nutritional profile:

• Crude protein: 10–25% (varies widely with maturity and fertilisation)
• NSC: Can be very high — 15–35% or more, especially in spring
• Digestible energy: High
• Fibre (NDF): Moderate — 40–55%

Pros: Excellent yield, palatability, and regrowth. Highly digestible.

Cons: The high sugar and fructan content makes it one of the riskiest grasses for laminitis-prone horses and those with metabolic conditions. NSC levels spike dramatically on cold, sunny days when the grass photosynthesises actively but doesn't grow fast enough to use those sugars.

Best for: Horses in moderate to hard work who need energy-dense forage. Not ideal for good doers or metabolically sensitive horses without careful management.

Timothy (*Phleum pratense*)

Timothy is one of the most popular grasses for horse hay worldwide, and for good reason. It's a reliable, well-understood forage.

Nutritional profile:

• Crude protein: 8–14%
• NSC: Moderate — typically 8–18%
• Digestible energy: Moderate
• Fibre (NDF): 55–65%

Pros: Lower sugar content than ryegrass, good fibre levels, palatable, and easy to manage. Excellent for hay production.

Cons: Doesn't tolerate heavy, continuous grazing as well as ryegrass. Slower to establish. Less productive in high-traffic paddocks.

Best for: A wide range of horses. Particularly good for leisure horses, veterans, and those needing a moderate-energy forage.

Orchardgrass / Cocksfoot (*Dactylis glomerata*)

Orchardgrass (called cocksfoot in the UK) is a productive, shade-tolerant grass that grows in clumps rather than forming a dense sward.

Nutritional profile:

• Crude protein: 10–18%
• NSC: Moderate — 10–20%
• Digestible energy: Moderate to high
• Fibre (NDF): 50–65%

Pros: Good nutritional balance, more shade-tolerant than most grasses, productive in spring and autumn.

Cons: Becomes stemmy and less palatable quickly if not grazed or cut regularly. Can form tussocks that horses avoid.

Best for: Mixed pastures, especially those with some tree cover. Good general-purpose horse grass when managed well.

Tall Fescue (*Festuca arundinacea*)

Tall fescue is extremely hardy and drought-tolerant, making it a practical choice for many climates.

Nutritional profile:

• Crude protein: 10–17%
• NSC: Moderate — 10–20%
• Digestible energy: Moderate
• Fibre (NDF): 50–65%

Pros: Highly durable, tolerates poor soils, drought, and heavy traffic. Lower sugar than ryegrass.

Cons: The major concern is endophyte infection. Some tall fescue varieties harbour a fungal endophyte (Epichloë coenophiala) that produces toxins linked to serious problems in pregnant mares, including prolonged gestation, thickened placentas, agalactia (no milk production), and foal loss. Always choose endophyte-free or novel endophyte varieties for horse pastures.

Best for: Hardwearing paddocks and horses not prone to metabolic issues. Avoid infected varieties for broodmares entirely.

Meadow Fescue (*Festuca pratensis*)

Meadow fescue is a gentler alternative to tall fescue — softer-leaved, palatable, and well-suited to horse pastures.

Nutritional profile:

• Crude protein: 10–16%
• NSC: Moderate
• Digestible energy: Moderate
• Fibre (NDF): 50–60%

Pros: Good digestibility, palatable, and generally lower in sugars than perennial ryegrass. Works well in mixed swards.

Cons: Less productive and less durable than ryegrass or tall fescue.

Best for: Mixed pastures for leisure horses and good doers who benefit from moderate-energy grazing.

Common Warm-Season Grasses for Horses

Bermudagrass (*Cynodon dactylon*)

Bermudagrass is the most widely used warm-season horse pasture grass in the southern US and similar climates.

Nutritional profile:

• Crude protein: 8–16% (highly dependent on fertilisation and maturity)
• NSC: Lower than most cool-season grasses — typically 8–15%
• Digestible energy: Moderate
• Fibre (NDF): 60–75%

Pros: Tolerates heat, drought, and heavy grazing. Lower NSC makes it safer for metabolically challenged horses.

Cons: Higher fibre can mean lower digestibility. Quality drops rapidly as the grass matures. Can become invasive.

Best for: Horses in hot climates. A solid choice for easy keepers and metabolically sensitive horses.

Teff Grass (*Eragrostis tef*)

Teff grass has gained significant popularity in the equine world as a low-sugar hay option.

Nutritional profile:

• Crude protein: 8–14%
• NSC: Low — typically 6–12%
• Digestible energy: Low to moderate
• Fibre (NDF): 55–70%

Pros: Consistently low in NSC, making it an excellent choice for horses with laminitis, EMS, PPID (Cushing's), or obesity. Fine-stemmed and palatable.

Cons: An annual crop — it must be resown each year. Primarily used for hay rather than grazing. Not available everywhere.

Best for: Metabolically compromised horses who need low-sugar forage. Increasingly popular as a specialist hay.

How Season and Management Affect Grass Nutrition

The nutritional value of any grass isn't fixed — it changes dramatically based on several factors:

Time of Year

• Spring brings the highest sugar levels in cool-season grasses, especially during rapid growth phases
• Autumn can also see sugar spikes, particularly during cool, sunny days
• Summer heat may reduce sugar in cool-season grasses (as growth uses up stored sugars) but increases it in warm-season grasses

Time of Day

Sugars accumulate during the day through photosynthesis and are used overnight for growth. Early morning grazing (before 10am) generally offers lower-sugar grass than afternoon grazing — a useful management tip for laminitis-prone horses.

Maturity

Young, leafy grass is higher in protein, energy, and sugars. As grass matures and goes to seed, fibre increases while protein and digestibility decrease. This is why mature hay is often recommended for good doers.

Fertilisation

Nitrogen fertilisation increases protein content and overall growth but may also increase NSC levels. Over-fertilised pastures can provide an unbalanced diet.

Frost and Stress

Stressed grass — from frost, drought, or overgrazing — often accumulates higher sugar levels because the plant produces sugars for energy but isn't growing enough to use them. Frosty mornings with sunny afternoons are among the highest-risk times for laminitis.

Choosing the Right Grass Mix for Your Horse

The best horse pastures are rarely a single species. A well-designed seed mix provides a range of nutrients, better ground cover, and more resilience against weather extremes and disease.

Here are some general guidelines:

For Horses in Work

A mix including perennial ryegrass, timothy, and orchardgrass provides good energy and palatability.

For Good Doers, Natives, and Metabolically Sensitive Horses

Reduce or eliminate ryegrass. Focus on timothy, meadow fescue, and include some native grasses and herbs. Consider track systems or strip grazing to limit intake.

For Broodmares

Higher-quality pasture with good protein and energy is appropriate, but always avoid endophyte-infected tall fescue.

For Veterans

Soft, palatable grasses like timothy and meadow fescue are kind on older teeth and digestive systems.

Don't Forget Pasture Herbs and Legumes

Grass alone doesn't tell the whole story. Many traditional horse pastures include beneficial herbs and legumes:

• Clover (white and red) — fixes nitrogen and adds protein, but can be high in phytoestrogens
• Chicory — deep-rooted, mineral-rich, and naturally lower in sugar
• Plantain — good mineral content and some anti-inflammatory properties
• Dandelion — natural source of vitamins and minerals
• Sainfoin — a legume with natural anti-parasitic properties and good protein levels

A diverse sward is not only more natural for horses — it often provides a more balanced mineral profile than a monoculture pasture.

Analysing What Your Horse Is Actually Eating

Knowing the general nutritional profile of grass types is a great starting point, but there's huge variation depending on your soil, climate, management, and time of year. The only way to truly know what your horse is getting from pasture is through forage analysis.

Once you have forage analysis results, analysing your horse's overall diet at MyEquiBalance can help you identify any gaps in vitamins, minerals, and macronutrients — and make targeted adjustments rather than guessing.

Key Takeaways

• Not all grasses are nutritionally equal. Perennial ryegrass is high in sugar and energy; timothy and meadow fescue are more moderate; teff grass is consistently low in sugar.
• Cool-season grasses tend to be higher in NSC than warm-season grasses, which matters for metabolically sensitive horses.
• Season, time of day, maturity, and stress all dramatically change the nutritional content of any grass.
• Endophyte-infected tall fescue is dangerous for pregnant mares — always use safe varieties.
• Mixed swards with herbs and legumes provide more balanced nutrition than monocultures.
• Forage testing and diet analysis are the most reliable ways to ensure your horse's pasture is meeting their needs.

Understanding what's growing in your paddock is one of the most impactful things you can do for your horse's health. It costs nothing to observe your pasture more carefully — and the knowledge can save you significant veterinary bills down the line.