Chaff for Horses: Which Type and How Much to Feed

What Is Chaff and Why Do Horses Need It?

Chaff is dried forage — usually hay or straw — that has been chopped into short lengths. It's one of the most commonly used feeds in the UK and Australia, and it's steadily gaining popularity worldwide. But despite being a staple in many feed rooms, chaff is often misunderstood. Horse owners frequently ask: Which type of chaff should I use? And how much should I feed?

The answers depend on your horse's workload, body condition, health status, and what else is in the bucket. In this guide, we'll break down every common type of chaff, explain the nutritional differences, and give you practical feeding guidelines.

Why Feed Chaff at All?

Before we dive into types and quantities, it's worth understanding why chaff earns its place in so many feed plans.

Slows Down Eating

Horses that bolt their hard feed risk choke, poor digestion, and colic. Mixing chaff through a concentrate feed forces the horse to chew more thoroughly. Each chew produces saliva, which buffers stomach acid and supports healthy digestion throughout the gastrointestinal tract.

Adds Fibre to the Bucket Feed

Fibre is the foundation of every good equine diet. Chaff adds a fibre source directly into the hard feed, complementing the hay or pasture your horse already receives.

Carries Supplements

A small amount of chaff is the perfect carrier for powdered supplements, balancers, or medications. It gives the powder something to stick to, so your horse actually consumes what you've added rather than leaving it at the bottom of the bucket.

Low-Calorie Bulk

For good doers or horses on restricted diets, certain types of chaff provide chew time and gut fill without piling on calories.

Types of Chaff for Horses

Not all chaff is created equal. The base forage, any coatings or additives, and the maturity at harvest all influence the nutritional profile. Here's a breakdown of the most common types.

Meadow Hay Chaff

Meadow hay chaff is made from traditional meadow hay — a mix of grasses and sometimes native herbs. It's moderate in energy and protein, making it a versatile, middle-of-the-road option.

• Best for: Most horses in light to moderate work; a safe everyday choice.
• Typical energy: Around 7–8 MJ DE/kg (dry matter basis).
• Protein: Roughly 6–10% crude protein.

Ryegrass Hay Chaff

Made from improved ryegrass pastures, this chaff tends to be slightly higher in energy and protein than meadow hay chaff. It's greener in colour and often more palatable.

• Best for: Horses in moderate to hard work that need a bit more energy from forage.
• Watch out: May be too rich for laminitics, overweight horses, or those prone to metabolic issues.

Lucerne (Alfalfa) Chaff

Lucerne chaff is a legume-based forage and stands apart nutritionally. It's significantly higher in protein, energy, and calcium than grass-based chaffs.

• Best for: Growing horses, broodmares, hard-working performance horses, and underweight horses that need condition.
• Typical energy: Around 9–10 MJ DE/kg.
• Protein: 15–20% crude protein.
• Calcium: Roughly 1.2–1.5%, which creates a high calcium-to-phosphorus ratio. This is generally beneficial, but it's important to ensure the overall diet remains balanced.
• Watch out: Not ideal as the sole chaff for horses prone to obesity or those with kidney issues. The higher protein and calorie content can contribute to weight gain if overfed.

Oaten Chaff

Popular in Australia, oaten chaff is made from oat hay — the entire oat plant cut before the grain fully matures. It's palatable, moderate in energy, and relatively low in protein.

• Best for: A general-purpose chaff; horses in light to moderate work.
• Typical energy: Around 7–9 MJ DE/kg, depending on the maturity at harvest.
• Protein: 5–9% crude protein.

Wheaten Chaff (Straw Chaff)

Wheaten chaff — or straw chaff — is made from the stems of wheat plants after the grain has been harvested. It's the lowest in nutritional value and is essentially a source of long-stem fibre with minimal energy or protein.

• Best for: Good doers, overweight horses, laminitics, and horses with Equine Metabolic Syndrome (EMS) who need a low-calorie carrier in their bucket feed.
• Typical energy: Around 5–6 MJ DE/kg.
• Protein: 3–5% crude protein.
• Watch out: Very low in vitamins and minerals, so it contributes almost nothing nutritionally beyond fibre. A balancer or supplement is essential alongside it.

Molassed Chaff

Some chaffs come coated in a light molasses dressing. This improves palatability and helps bind dust, but it adds sugar. Molassed chaffs typically contain 3–8% added sugar.

• Best for: Fussy eaters, horses in hard work, or as an occasional palatability booster.
• Avoid for: Laminitics, horses with insulin dysregulation, EMS, PPID (Cushing's), or those on a low-sugar diet. Always check the label — many brands now offer molasses-free alternatives.

Herbal and Oil-Coated Chaffs

Some commercial chaffs include added herbs (such as mint or chamomile), oils (soya or linseed), or vitamins and minerals. These can be useful but read the ingredient list carefully. The nutritional contribution of these additives varies widely between brands.

How to Choose the Right Chaff for Your Horse

Selecting the right chaff comes down to matching it to your horse's individual needs. Here's a quick decision framework:

When in doubt, start with a plain meadow hay chaff. It's the safest all-rounder.

How Much Chaff Should You Feed?

This is where many horse owners go wrong — either by feeding too much chaff (and not enough long-stem forage) or by underestimating how much chaff contributes to the overall diet.

General Guidelines

For most horses, chaff is a small component of the total diet, not a replacement for hay or pasture. Here are sensible starting points:

• As a feed mixer / supplement carrier: 200–500g per feed (one to two large handfuls).
• As a meaningful forage source in the bucket: 500g–1.5kg per feed, depending on the horse's size, workload, and what other forage is available.
• Maximum practical amount: Up to 2kg per feed for a 500kg horse in hard work, mixed with concentrates. Beyond this, you're better off providing additional hay.

Chaff Should Not Replace Long-Stem Forage

This is a critical point. Chaff is chopped forage, and while it still provides fibre, it doesn't promote the same jaw movement and chewing patterns as long-stem hay. Horses need long-stem forage — hay, haylage, or pasture — to maintain healthy dental wear, gut motility, and psychological wellbeing.

A good rule of thumb: your horse's total forage intake (hay + pasture + chaff) should be at least 1.5–2% of bodyweight per day in dry matter. Chaff should make up only a portion of that total.

For a 500kg horse, that means at least 7.5–10kg of forage dry matter daily, with the majority coming from hay or pasture and chaff contributing perhaps 0.5–2kg of that total.

Adjusting Amounts by Horse Type

• Good doers: Use a small amount (200–400g) of low-calorie chaff purely as a supplement carrier. Keep overall calories in check.
• Performance horses: Can have larger chaff meals (1–2kg per feed) of lucerne or ryegrass chaff alongside concentrates, as the extra energy and protein supports workload demands.
• Horses on box rest or restricted turnout: A moderate amount of chaff (500g–1kg per feed) can help extend feeding time and reduce boredom, but long-stem hay in a small-holed net should still be the primary forage source.

Feeding Chaff Safely: Practical Tips

Always Introduce Gradually

Like any feed change, introduce chaff over 7–14 days. Sudden changes in forage type can disrupt the hindgut microbiome and increase the risk of colic.

Check for Quality

Good chaff should smell sweet and fresh, not musty or sour. It should be free of dust, mould, and foreign objects. If it smells off, don't feed it — the risk of respiratory issues and mycotoxin exposure isn't worth it.

Store Properly

Keep bagged chaff sealed in a cool, dry environment. Once opened, use it within a few weeks, especially in warm or humid weather. Chaff can spoil faster than baled hay because of the increased surface area of the chopped pieces.

Weigh Your Chaff

Different chaffs have very different densities. A scoop of lucerne chaff weighs considerably more than the same scoop of straw chaff. Invest in a simple kitchen or luggage scale and weigh what you're actually feeding. You might be surprised.

Balancing the Whole Diet

Chaff is just one piece of the nutritional puzzle. What matters most is how it fits within the total diet — alongside hay, pasture, hard feed, and supplements. Feeding too much high-protein lucerne chaff alongside a high-protein hard feed, for example, can push protein intake beyond what your horse needs, putting unnecessary strain on the kidneys and potentially causing issues.

The best way to know whether your chaff choice and quantity are right is to look at the diet as a whole. Analysing your horse's diet helps you see exactly where the energy, protein, vitamins, and minerals are coming from — and where the gaps might be. It takes the guesswork out of feeding and ensures your chaff is doing its job without causing imbalances.

Frequently Asked Questions About Chaff for Horses

Can I feed chaff as the only forage?

No. Chaff should complement long-stem forage, not replace it. Horses need the chewing time and gut-fill that hay or pasture provides.

Is lucerne chaff too rich for my horse?

It depends on your horse's workload and condition. For a lightly worked, overweight cob, lucerne chaff is likely unnecessary and could contribute to weight gain. For a hard-working Thoroughbred or a growing youngster, it can be an excellent source of quality protein and calcium.

Can chaff cause colic?

Chaff itself doesn't cause colic, but feeding large amounts of dry chaff without adequate water intake could theoretically contribute to impaction in susceptible horses. Always ensure fresh water is available and consider dampening chaff slightly if your horse is a poor drinker.

Should I soak chaff for a laminitic horse?

Soaking removes water-soluble carbohydrates (sugars) from forage. This is commonly done with hay but is less practical with chaff due to the small particle size. Instead, choose a low-sugar, unmolassed straw or meadow hay chaff and check the manufacturer's guaranteed analysis for sugar and starch levels. Aim for combined sugar + starch below 10% for at-risk horses.

How do I know which chaff brand is best?

Look for brands that publish a full nutritional analysis on the bag or their website. Transparency about energy, protein, fibre, sugar, and starch content is a sign of a quality product. Avoid brands that don't disclose these figures.

Summary

Chaff is a practical, versatile addition to most horses' diets. It slows eating, adds fibre to the bucket, and acts as an excellent supplement carrier. The key is choosing the right type for your horse's needs and feeding it in appropriate amounts.

• Meadow hay and oaten chaff are safe, versatile all-rounders.
• Lucerne chaff is a powerhouse for horses needing extra protein, energy, and calcium.
• Straw chaff is the go-to for good doers and metabolically compromised horses.
• Avoid molassed chaffs for laminitics, EMS, and PPID horses.
• Feed 200g–2kg per meal, depending on your horse's needs, and always prioritise long-stem forage as the foundation of the diet.

Get the chaff right, and you're supporting better digestion, slower eating, and a more balanced bucket feed — all of which contribute to a healthier, happier horse.