Hay vs Haylage for Laminitis-Prone Horses: A Complete Guide

If your horse has ever suffered from laminitis — or is at high risk — you already know that every feeding decision matters. One of the most common questions horse owners face is whether to feed hay or haylage. Both are staple forages, but they differ in important ways when it comes to sugar content, digestibility, and overall safety for laminitis-prone horses.

In this guide, we'll break down the pros and cons of each, explain the science behind water-soluble carbohydrates (WSC), and give you practical advice for keeping your horse safe and well-fed.

Understanding Laminitis and the Role of Forage

Laminitis is a painful and potentially life-threatening condition involving inflammation and damage to the laminae — the tissue structures that connect the hoof wall to the pedal bone. While laminitis has several possible causes, one of the most common triggers in the UK and Ireland is excessive intake of non-structural carbohydrates (NSC), which includes sugars and fructans found in grass and conserved forages.

Forage makes up the largest portion of most horses' diets — typically 1.5% to 2% of bodyweight per day in dry matter terms. That means if your forage is high in sugar, your horse is consuming a large quantity of the very thing that could trigger a laminitic episode. Choosing the right forage is therefore one of the single most impactful decisions you can make for a laminitis-prone horse.

What's the Difference Between Hay and Haylage?

Before comparing their suitability for laminitis-prone horses, let's clarify what hay and haylage actually are.

Hay

Hay is grass that has been cut and dried in the field until its moisture content drops to around 15% or less. It is then baled and stored. The low moisture content means that hay can be stored for long periods without spoiling, provided it's kept dry and well-ventilated.

Haylage

Haylage is grass that has been cut and wilted to a higher moisture content — typically between 30% and 50% — then baled and wrapped in plastic. The airtight wrapping creates an anaerobic (oxygen-free) environment in which beneficial lactic acid bacteria ferment the plant sugars, lowering the pH and preserving the forage. This is essentially the same process used to make silage for cattle, but haylage is drier and coarser.

Sugar Content: The Critical Factor

For laminitis-prone horses, the key nutritional concern with any forage is its water-soluble carbohydrate (WSC) content. WSC includes simple sugars and fructans — the carbohydrates most strongly linked to pasture-associated laminitis.

WSC in Hay

The sugar content of hay depends heavily on the grass species, when it was cut, and the conditions at the time of cutting. Hay cut from ryegrass-dominant pastures on a sunny afternoon, for example, can be very high in WSC. Conversely, hay cut from mature, stemmy grass on an overcast day may have much lower sugar levels.

Crucially, the sugars present in the grass at the time of cutting are largely preserved in hay. Drying locks in the plant's carbohydrate profile. This means hay can be either low or high in sugar — you simply cannot tell by looking at it.

WSC in Haylage

Here's where things get interesting. During the fermentation process that occurs inside wrapped haylage bales, lactic acid bacteria consume some of the water-soluble carbohydrates as fuel. This means that well-fermented haylage will typically have a lower WSC content than hay made from the same crop.

However — and this is a significant "however" — the reduction in WSC is not always dramatic, and it depends on how well the fermentation process has proceeded. Poorly fermented haylage (due to insufficient wilting, air getting into the bale, or low bacterial activity) may retain relatively high sugar levels. Furthermore, the fermentation process produces volatile fatty acids and other compounds that increase the overall energy density of haylage, which brings its own risks for laminitis-prone horses.

The Bottom Line on Sugar

On average, haylage tends to have a lower WSC percentage on a dry matter basis than hay. But "tends to" is not the same as "always will." Without laboratory analysis, you are guessing — and guessing is not good enough when laminitis is a real possibility.

Energy Content and Weight Gain

Laminitis-prone horses are often — though not always — overweight or have Equine Metabolic Syndrome (EMS). Managing body condition is a critical part of laminitis prevention, so the energy content of forage matters just as much as its sugar content.

Haylage Is Typically Higher in Energy

Because haylage is cut at an earlier stage of growth and undergoes fermentation, it tends to be more digestible and energy-dense than hay on a dry matter basis. The fermentation products themselves (volatile fatty acids like lactic acid and acetic acid) contribute additional energy. For a good doer or an overweight horse, this extra energy can be a problem.

Many horse owners notice that their horses gain weight or become fizzy when switched to haylage, and this is a direct consequence of its higher energy content.

Hay Offers More Control

Late-cut, stalky hay is generally lower in energy and higher in fibre. For laminitis-prone horses that need to lose weight or maintain a healthy body condition, this type of hay can be a better option — provided the sugar content has been checked and is within an acceptable range.

Soaking Hay: A Proven Strategy

One major advantage hay has over haylage is that it can be soaked in water to reduce its WSC content. Research has consistently shown that soaking hay for 30 to 60 minutes in clean, cold water can reduce sugar levels by approximately 20% to 40%, though results vary depending on the initial sugar content and the type of sugars present.

How to Soak Hay Effectively

Use a large container or haynet submerged in a water trough.
Soak for 30 to 60 minutes in cold water, or 15 to 30 minutes in warm water.
Drain the hay thoroughly before feeding.
Do not re-use the soak water — it is high in sugars and can be harmful if consumed.
Feed soaked hay within a few hours, as it spoils quickly, especially in warm weather.

Why You Can't Soak Haylage

Haylage cannot be soaked in the same way because its preservation depends on the anaerobic fermentation environment. Introducing water and air to haylage would disrupt this, encouraging the growth of harmful moulds and bacteria. Once haylage is removed from its wrapping, it should be fed within one to two days in cooler weather and even sooner in summer.

This inability to soak is a meaningful disadvantage of haylage for laminitis management, because soaking gives horse owners an additional safety net when sugar levels are uncertain.

Forage Analysis: The Non-Negotiable Step

Whether you choose hay or haylage, the single most important step you can take is to have your forage analysed by a laboratory. A standard forage analysis will tell you the WSC content, dry matter percentage, crude protein, digestible energy, and mineral profile of your forage.

For laminitis-prone horses, most nutritionists recommend choosing forage with a WSC content below 10% on a dry matter basis. Some particularly sensitive horses may need even lower levels.

Without analysis, you are feeding blind. Two bales of hay from the same field can have significantly different sugar levels depending on cutting conditions. The same applies to haylage.

Once you know the nutritional profile of your forage, you can then work on analysing your horse's overall diet to make sure the rest of their feed plan — including any balancers, supplements, or hard feed — complements the forage and meets their nutritional needs without excess energy or sugar.

Hay vs Haylage: Practical Pros and Cons for Laminitis-Prone Horses

Advantages of Hay

Can be soaked to reduce sugar content by 20–40%.
Late-cut hay is often lower in energy, making it easier to manage weight.
Longer shelf life when stored correctly — no risk of spoilage once bale is opened.
Easier to weigh accurately due to low, consistent moisture content.
Widely available and familiar to most horse owners.

Disadvantages of Hay

Sugar content can be high and varies enormously between batches.
Dust and mould spores can be an issue, particularly for horses with respiratory problems.
Quality is weather-dependent — a wet summer can mean poor hay crops.

Advantages of Haylage

Generally lower WSC than hay on a dry matter basis (due to fermentation).
Low dust — an excellent option for horses with respiratory issues like RAO (recurrent airway obstruction).
More palatable for many horses, which can be useful for poor eaters.
Less weather-dependent during production — can be made in less-than-ideal conditions.

Disadvantages of Haylage

Higher energy content — can cause weight gain in good doers.
Cannot be soaked to reduce sugars further.
Spoils quickly once the bale is opened — risk of botulism and other toxins if improperly made or stored.
Harder to weigh accurately due to variable moisture content — you need to account for water weight when calculating dry matter intake.
Fermentation acids may not suit all horses' digestive systems.

So Which Should You Choose?

There is no single right answer that applies to every laminitis-prone horse. However, here is a general decision framework:

Choose Hay If:

Your horse is overweight or a good doer.
You want the option to soak forage to reduce sugars.
You can source late-cut, stemmy hay and have it analysed.
Your horse does not have significant respiratory issues.

Choose Haylage If:

Your horse has respiratory problems that make hay unsuitable, even when soaked.
You can source haylage that has been well-fermented and analysed to confirm low WSC.
Your horse is not overweight and can handle the additional energy.
You are confident in the quality and safety of the product.

Consider a Combination

Some owners use a mix of both — feeding analysed, soaked hay as the main forage source and offering a small amount of haylage to horses that struggle with dry, dusty hay. This can work well, provided the total diet is carefully balanced.

Other Forage Strategies for Laminitis-Prone Horses

Beyond choosing between hay and haylage, there are several additional strategies to support laminitis-prone horses:

Use small-hole haynets or slow feeders to extend eating time and mimic natural grazing behaviour without increasing intake.
Weigh your forage daily rather than guessing. Restrict to 1.5% of bodyweight in dry matter if weight loss is needed, but never go below 1.25% without veterinary supervision.
Limit or eliminate pasture access during high-risk periods — particularly in spring and autumn when grass sugar levels peak.
Avoid high-sugar hard feeds — opt for low-calorie, low-starch balancers instead.
Monitor body condition regularly using a body condition scoring system.

Final Thoughts

When it comes to feeding laminitis-prone horses, the choice between hay and haylage is less about which is universally "better" and more about which is safer for your individual horse in your specific circumstances. Both can be suitable — and both can be dangerous — depending on their sugar content, energy levels, and how they're managed.

The golden rule is simple: test your forage. Without a laboratory analysis, you cannot make an informed decision. Once you know what's in your forage, you can build a complete, balanced, and safe diet around it.

Laminitis is a condition where prevention is infinitely better than cure. Taking the time to understand your forage options and make evidence-based choices could be the difference between a comfortable horse and a veterinary emergency. Your horse is counting on you to get this right.

Hay vs Haylage for Laminitis-Prone Horses: A Guide