Haylage for Horses: Benefits, Risks and How to Feed It Safely

Haylage has become one of the most popular forage options for horses in the UK and beyond. Whether you're looking for a dust-free alternative to hay, trying to encourage a fussy eater, or simply want to provide consistent-quality forage, haylage can be a fantastic choice — but only when you understand how to use it properly.

In this guide, we'll cover everything you need to know about feeding haylage to horses, including its nutritional profile, the real benefits, the genuine risks, and practical tips for feeding it safely.

What Is Haylage?

Haylage is grass that has been cut and allowed to wilt in the field before being baled at a higher moisture content than traditional hay. While hay is typically dried to around 15% moisture, haylage is baled at roughly 30–50% moisture and then wrapped in multiple layers of plastic film to create an airtight seal.

Once sealed, the grass undergoes a controlled fermentation process. Naturally occurring bacteria convert sugars in the grass into lactic acid, which lowers the pH and preserves the forage. This is the same basic principle behind making silage for cattle, but haylage is drier and ferments more gently, making it better suited to horses.

Haylage vs Hay: What's the Difference?

The key differences between haylage and hay come down to moisture content, preservation method, and nutritional profile:

• Moisture content: Hay contains around 12–16% moisture; haylage contains 30–50%.
• Preservation: Hay is preserved by drying; haylage is preserved by fermentation in an anaerobic (oxygen-free) environment.
• Dust and spores: Properly made haylage is virtually dust-free, while hay — even good hay — contains varying levels of fungal spores and dust particles.
• Nutritional value: Haylage typically retains more nutrients than hay because the shorter wilting period means fewer vitamins and sugars are lost to weathering and prolonged sun exposure.
• Palatability: Most horses find haylage more palatable than hay due to its softer texture and slightly sweet, fermented taste.

Benefits of Feeding Haylage to Horses

There are several genuine advantages to including haylage in your horse's diet.

1. Low Dust Content

This is the single biggest reason many horse owners switch to haylage. Horses with respiratory conditions such as Recurrent Airway Obstruction (RAO), commonly known as heaves, or Inflammatory Airway Disease (IAD) benefit enormously from dust-free forage. Good-quality haylage contains virtually no airborne fungal spores or dust, making it far kinder to the respiratory system than even the best hay.

2. Higher Nutritional Value

Because haylage spends less time wilting in the field, it retains more of the original nutrients found in the living grass. This typically means higher levels of protein, energy, and certain vitamins compared to hay made from the same sward. For horses in moderate to hard work, growing youngstock, or broodmares, this can be a real advantage.

3. Better Palatability

Fussy eaters and older horses who struggle with dry, stalky hay will often eat haylage readily. The softer texture also makes it easier to chew, which is a significant benefit for horses with dental problems.

4. Contribution to Hydration

The higher moisture content of haylage means your horse takes in more water with every mouthful. While this shouldn't replace access to fresh drinking water, it can help support hydration — particularly useful in winter when some horses drink less.

5. Consistent Quality

Because haylage is less dependent on a long period of dry weather for preservation, producers can often achieve more consistent quality from cut to cut and year to year. Hay, by contrast, is at the mercy of the weather during a critical drying window.

Risks of Feeding Haylage to Horses

Haylage is not without its risks. Understanding these is essential for keeping your horse safe.

1. Risk of Botulism

This is the most serious risk associated with haylage. The bacterium Clostridium botulinum can thrive in anaerobic conditions if the fermentation process doesn't achieve a low enough pH. Contamination is more likely when:

• Bales are punctured or the wrap is damaged, allowing air in.
• Soil or animal carcasses (such as rodents) are incorporated into the bale.
• The grass wasn't wilted sufficiently before wrapping.

Botulism in horses is often fatal. Signs include progressive muscle weakness, difficulty swallowing, drooping eyelids, and eventual paralysis. If you suspect botulism, contact your vet immediately.

2. Higher Sugar and Energy Content

Because haylage retains more of the original plant sugars, it is often higher in water-soluble carbohydrates (WSC) than hay. This can be problematic for horses prone to laminitis, those with Equine Metabolic Syndrome (EMS), or those with Pituitary Pars Intermedia Dysfunction (PPID/Cushing's disease). For these horses, you need to know the exact sugar content of your haylage before feeding it.

3. Shorter Shelf Life Once Opened

Once a haylage bale is opened and the airtight seal is broken, the forage begins to spoil. In warm weather, mould can develop within 3–5 days. Even in cooler conditions, an opened bale should ideally be used within a week. This makes haylage less practical for owners with only one or two horses, as large bales may spoil before they're finished.

4. Overfeeding and Weight Gain

Because haylage is more palatable and more energy-dense than hay, horses can easily overconsume it. Owners who switch from hay to haylage on a weight-for-weight basis often inadvertently increase their horse's calorie intake significantly. This is a common cause of weight gain and can increase the risk of laminitis.

5. Inconsistent Fermentation

Not all haylage is created equal. Poorly made haylage — where fermentation has been incomplete or where the bale has been contaminated — can harbour harmful bacteria, yeasts, and moulds. Unlike hay, where you can often see and smell problems, spoilage in haylage can sometimes be hidden within the bale.

How to Feed Haylage Safely

With the right precautions, haylage can be a safe and excellent forage for most horses. Here's how to get it right.

Choose a Reputable Supplier

Buy from a producer who understands equine haylage. Horse haylage should be made from appropriate grass species, cut at the right stage of maturity, and properly wilted before being wrapped in a minimum of six layers of plastic. Ask about their production methods and whether they test their product.

Inspect Every Bale

Before feeding, check every bale for:

• Wrap integrity: Look for punctures, tears, or areas where the plastic has been compromised by vermin, birds, or handling damage.
• Smell: Good haylage should smell sweet and slightly tangy, like pickled grass. Reject any bale that smells rancid, musty, alcoholic, or strongly of ammonia.
• Colour: It should be olive green to golden brown. Avoid bales with patches of white, black, or blue mould.
• Texture: The forage should feel soft and slightly moist, not slimy or excessively wet.

If in doubt, don't feed it. No bale of forage is worth the risk to your horse's life.

Adjust Feeding Quantities

This is where many owners go wrong. Because haylage contains 30–50% water, you need to feed more of it by weight to provide the same amount of dry matter as hay.

As a rough guide:

• If your horse eats 10 kg of hay per day, you may need to provide approximately 12–15 kg of haylage to deliver the same dry matter intake.
• However, because haylage is often more energy-dense on a dry matter basis, you should also factor in the higher calorie content.

The safest approach is to have your haylage analysed for dry matter, energy, protein, and sugar content. This allows you to analyse your horse's diet accurately and make precise adjustments rather than guessing.

Use Haylage Promptly Once Opened

Once you break the seal on a bale, aim to use it within:

• 3–5 days in warm weather (above 15°C)
• 5–7 days in cool weather

If you have a small number of horses, consider buying smaller bales — or even individually wrapped small bales designed for one or two horses.

Store Bales Correctly

Store haylage bales on a flat, clean surface away from sharp objects, machinery, and areas where vermin might damage the wrap. Keep bales off bare ground if possible — pallets or a concrete pad work well. Never stack bales more than three high, and always use the oldest bales first.

Consider Vaccination Against Botulism

In some regions, vaccination against Clostridium botulinum is available and recommended for horses that regularly eat haylage. Speak to your vet about whether this is appropriate for your horse.

Which Horses Benefit Most from Haylage?

Haylage can be particularly beneficial for:

• Horses with respiratory issues: The dust-free nature of haylage makes it the forage of choice for horses with RAO or IAD.
• Older horses with dental problems: The softer texture is easier to chew and digest.
• Horses in hard work: The higher energy and protein content can help meet increased nutritional demands.
• Poor doers and fussy eaters: The palatability of haylage often encourages better forage intake.
• Broodmares and growing youngstock: The retained nutrients support the higher nutritional requirements of these groups.

Which Horses Need Caution with Haylage?

Extra care is needed when feeding haylage to:

• Overweight horses and good doers: The higher calorie content and palatability can lead to excessive weight gain.
• Horses prone to laminitis, EMS, or PPID: The potentially higher sugar content may trigger or worsen metabolic issues. Always have haylage tested for WSC before feeding it to these horses.
• Horses on restricted diets: It's harder to control calorie intake with haylage unless you know the exact nutritional analysis.

Frequently Asked Questions About Haylage

Can you soak haylage like hay?

Soaking haylage is not generally recommended. Haylage already has a high moisture content, and soaking can disrupt the fermentation balance, encouraging harmful bacterial growth. If you need to reduce sugar content, choose a naturally low-sugar haylage or consider steaming.

How do I know if my haylage has gone bad?

Look for visible mould, an unpleasant or unusual smell (rancid, alcoholic, or putrid), sliminess, or excessive heat when you put your hand into the bale. Any of these signs mean you should discard the forage immediately.

Can I mix haylage and hay?

Yes, many owners feed a combination of hay and haylage successfully. This can be a good strategy to provide some dust-free forage while managing calorie intake. Just be sure to account for the different moisture and energy levels of each when calculating daily rations.

How long does a sealed bale of haylage last?

A properly sealed, undamaged bale of haylage can last 12–18 months or even longer. However, the nutritional quality may decline slowly over time, so it's best used within 12 months of production.

Final Thoughts

Haylage is a versatile, high-quality forage that suits many horses extremely well. Its dust-free nature, excellent palatability, and retained nutritional value make it a standout choice for a wide range of horses. However, it demands more care in storage, inspection, and feeding management than hay.

The golden rules are simple: buy from a trusted source, inspect every bale before feeding, adjust quantities to account for moisture and energy differences, use opened bales promptly, and always know what's in your forage through proper nutritional analysis.

Get these basics right, and haylage can be one of the best things you ever add to your horse's diet.