How Much Concentrate Should You Feed a Horse Per Meal?

By Dr Duncan Houston

Concentrate feed can be useful when forage alone cannot meet a horse’s energy or nutritional requirements. It is also one of the easiest parts of the diet to overfeed.

A ration balancer, performance pellet, complete senior feed and scoop of corn may all arrive in a bucket, but they are not nutritionally interchangeable. The real concern is not simply the size of the bucket. It is the amount of starch, sugar and energy delivered in one meal, how quickly the horse eats it, and whether the ration suits that individual horse.

Large grain-based meals can overwhelm small-intestinal starch digestion, allowing more starch to reach the hindgut. Rapid fermentation can then disrupt the normal microbial population, lower hindgut pH and increase the risk of digestive upset, colic and laminitis.

Quick Answer

For grain-based concentrates, horses should not receive more than 0.5% of their body weight in a single meal. For a 500-kilogram or 1,100-pound horse, that is an upper limit of approximately 2.5 kilograms or 5.5 pounds per meal.

This is a maximum ceiling, not a recommended target. Smaller meals are generally preferable, particularly for horses with gastric ulcers, metabolic disease, previous laminitis or a history of digestive problems. Larger daily amounts should be divided into several meals spaced approximately four to six hours apart, with forage kept available whenever the horse’s body condition and health allow. (Merck Veterinary Manual)

What Is a Concentrate Feed?

The word “concentrate” is used loosely around horse properties.

It may refer to straight grain, a commercial performance feed, a low-calorie ration balancer or even a complete senior ration. These products have very different purposes and should not all be fed using the same rules.

Feed type	Main purpose	Important consideration
Straight grain	Concentrated starch energy	Must be balanced for protein, minerals and vitamins
Grain-based commercial feed	Energy plus nutritional fortification	Meal size and starch content matter
High-fibre performance feed	Calories from fibre, fat and sometimes grain	May be lower in starch, but is not automatically low calorie
Ration balancer	Protein, vitamins and minerals with few calories	Usually fed in small amounts
Complete feed	Replaces some or all long-stem forage	Requires a much higher daily feeding rate and several meals
Forage pellets or cubes	Forage replacement or supplement	May need soaking for horses at risk of choke

Ration balancers are typically fed at approximately 0.5 to 0.9 kilograms, or one to two pounds, daily for a 500-kilogram horse. Complete feeds may need to be fed at around 1% to 1.5% of body weight per day because they are intended to replace some or all forage. Feeding a complete feed far below its labelled rate may provide calories without enough of the vitamins, minerals or protein the product was designed to supply. (Merck Veterinary Manual)

The shape of the feed does not tell you what is inside it.

A pellet may be high in cereal starch, primarily digestible fibre, or formulated as a forage replacement. Read the purpose statement and feeding directions rather than assuming all pellets are safer than all grains.

Does Every Horse Need Concentrate?

No.

Many healthy adult horses at maintenance or in light work can meet their energy requirements through good-quality pasture or hay. They may need only forage, water, salt and possibly a ration balancer to correct protein, vitamin or mineral gaps. (Merck Veterinary Manual)

Concentrate becomes more useful when the horse:

• Cannot maintain weight on adequate forage

• Performs moderate, heavy or very heavy work

• Is growing

• Is in late pregnancy or lactation

• Has poor-quality or restricted forage

• Has reduced chewing ability

• Requires a medically prescribed diet

• Needs nutrients that are missing from the forage

Before increasing concentrate for a thin horse, ask why the horse is thin. Dental disease, inadequate forage, parasites, gastric disease, chronic pain, social competition, PPID, poor feed quality and systemic illness can all cause weight loss.

Adding another scoop may hide the problem without fixing it.

How Much Grain-Based Concentrate Can a Horse Have Per Meal?

The general maximum is 0.5% of the horse’s body weight per meal.

Horse body weight	Maximum grain-based concentrate per meal
250 kg / 550 lb	1.25 kg / 2.75 lb
400 kg / 880 lb	2 kg / 4.4 lb
500 kg / 1,100 lb	2.5 kg / 5.5 lb
600 kg / 1,320 lb	3 kg / 6.6 lb

These amounts are upper limits, not ideal meal sizes. A horse does not benefit from having every meal pushed right to the safety ceiling.

A 250-kilogram pony should not receive the same five-pound meal as a 500-kilogram Thoroughbred simply because both feeds arrive in the same scoop. (Merck Veterinary Manual)

Starch May Set a Lower Limit Than Feed Weight

The total weight of the meal is only part of the calculation.

For horses at risk of equine squamous gastric disease, consensus guidance recommends keeping starch below approximately:

• 1 gram per kilogram of body weight per meal

• 2 grams per kilogram of body weight per day

For a 500-kilogram horse, that means no more than approximately 500 grams of starch in one meal.

If a feed contains 30% starch, 500 grams of starch would be supplied by only about 1.7 kilograms of feed. That is well below the general 2.5-kilogram concentrate ceiling.

If the feed contains 15% starch, approximately 3.3 kilograms would provide 500 grams of starch, but the 2.5-kilogram grain-based meal limit would then become the more restrictive rule.

This is why knowing the starch content matters.

NSC, or nonstructural carbohydrate, includes starch and sugars. Ask the manufacturer for starch and sugar values separately when they are not printed on the feed label.

How Many Concentrate Meals Should a Horse Receive?

The number of meals depends on the total daily amount and the type of product.

A horse receiving a small quantity of ration balancer may be managed according to the labelled once-daily or twice-daily directions.

A horse receiving several kilograms of grain-based performance feed needs the ration divided much more carefully.

For example, a 500-kilogram horse receiving:

• 2 kilograms daily could receive two 1-kilogram meals

• 4 kilograms daily would be better divided into at least three meals

• 5 to 6 kilograms daily should usually be divided into three or four meals, with the entire ration reviewed for safer fibre and fat alternatives

Merck recommends separating grain-based concentrate meals by at least four hours. Gastric-ulcer consensus guidance uses approximately six hours between concentrate meals, while still maintaining frequent or continuous access to forage. (Merck Veterinary Manual)

Do not serve three large meals within one afternoon and call the ration “frequent feeding.” The hindgut remains unconvinced by creative accounting.

Why Are Large Concentrate Meals Dangerous?

Horses digest starch mainly in the small intestine.

The amount digested before the hindgut depends on:

• The grain source

• Processing

• Meal size

• Eating rate

• The horse’s individual digestive capacity

• What else is being fed

When more starch is supplied than the small intestine can manage, additional starch reaches the caecum and colon. Hindgut bacteria ferment it rapidly, increasing lactic acid production and lowering pH.

Experimental high-starch feeding has been shown to:

• Increase starch-fermenting bacteria

• Reduce fibre-digesting bacteria

• Increase lactic acid

• Lower caecal and colonic pH

• Alter normal fermentation patterns

These changes help explain why excessive concentrate feeding can contribute to gas production, loose manure, colic, colitis and laminitis. (PubMed)

The risk is not simply that the stomach is too small to hold a large meal. The more important problem is what happens when the quantity and composition of the meal exceed the digestive system’s ability to process it safely.

Should You Feed Hay Before Concentrate?

Yes, feeding forage before concentrate is a sensible practical approach, particularly for horses receiving starch-rich feed.

A 2025 crossover study involving four caecally cannulated horses compared oats given before hay with hay given before oats. Feeding hay first delayed the peak measurement associated with gastric emptying and delayed the fall in caecal pH. The authors recommended considering forage before concentrate in practical feeding programmes. (OUP Academic)

The study was small and used a relatively modest starch meal, so it should not be interpreted as proof that hay protects a horse from any quantity of grain.

Forage first does not make an oversized concentrate meal safe.

A practical routine is:

1. Ensure the horse has not been fasting for hours.

2. Offer forage before the concentrate.

3. Keep the grain-based meal small.

4. Allow continuous or frequent forage access afterwards.

5. Maintain unrestricted clean water.

Avoid Long Periods Without Forage

Intermittent feed deprivation lowers the pH within the upper portion of the equine stomach and can contribute to squamous gastric ulceration.

Consensus guidance recommends at least 1.5 kilograms of forage dry matter per 100 kilograms of body weight daily, with free-choice access or frequent forage meals where appropriate. Gaps longer than approximately six hours between forage meals have been associated with increased risk of squamous gastric disease. (PubMed)

For an overweight or insulin-dysregulated horse, this does not mean unlimited rich hay.

It means providing an appropriately measured, low-energy forage ration through slow feeders or several meals so the horse is not repeatedly fasted.

Concentrate Feeding and Gastric Ulcers

Concentrate does not cause every gastric ulcer, and equine gastric ulcer syndrome includes more than one disease.

High starch intake, large grain meals, fasting and intense exercise are most strongly associated with equine squamous gastric disease. Equine glandular gastric disease is more complex, and diet is only one part of its risk profile. (PMC)

Concentrate-related ulcer risk becomes more concerning when a horse:

• Receives large starch-heavy meals

• Has long periods without forage

• Is fed only twice daily despite high concentrate requirements

• Exercises intensely on an empty stomach

• Travels frequently

• Has restricted turnout

• Has a previous ulcer diagnosis

Reducing starch, increasing appropriate forage access and dividing concentrate into smaller meals can support gastric health. They do not replace gastroscopy or veterinary treatment when ulcers are suspected.

Concentrate Feeding and Colic

Dietary change is one of the more consistently reported management risks for colic.

Studies and reviews have associated increased colic risk with:

• A recent change in the type of concentrate

• A new batch or type of hay

• Reduced pasture exposure

• Larger concentrate intake

• Abrupt changes in the amount fed

This does not mean every horse receiving grain will develop colic. It means the amount, transition, feeding pattern and individual horse matter. (PubMed)

Introduce a new concentrate gradually over approximately 10 to 14 days. Change one major part of the ration at a time where possible, and monitor appetite, manure and behaviour throughout the transition. (extension.psu.edu)

Should Concentrate Be Fed Before Exercise?

Avoid giving a large grain-based meal immediately before strenuous work, transport or another significant stress.

Merck advises against meals larger than 0.25% of body weight within one hour of hard exercise, transport or similar stress. Large concentrate meals should also not be offered to an exhausted horse with reduced gut motility. (Merck Veterinary Manual)

For a 500-kilogram horse, 0.25% of body weight is 1.25 kilograms.

The practical approach is:

• Maintain forage access

• Avoid a large grain meal immediately before intense exercise

• Allow the horse to recover and rehydrate before giving a substantial concentrate meal

• Feed the usual ration rather than suddenly “replacing energy” with extra grain

Horses do not carbohydrate-load in the same way human athletes do, and suddenly increasing grain after hard work does not accelerate muscle recovery. (Merck Veterinary Manual)

Which Concentrate Is Right for Your Horse?

Maintenance Horses and Easy Keepers

Many need little or no calorie-dense concentrate.

A ration balancer may be more appropriate when the forage supplies adequate calories but lacks protein, vitamins or minerals.

Performance Horses

Performance horses may need additional energy, but the ration does not have to rely entirely on cereal grain.

Safer energy sources can include:

• Digestible fibre

• Beet pulp

• Soy hulls

• Vegetable oil

• Stabilised rice bran

• Higher-fat commercial performance feeds

Healthy high-performance horses still require enough carbohydrate to support exercise and glycogen recovery. The goal is not to remove all starch indiscriminately. It is to avoid unnecessary starch overload while meeting genuine energy requirements. (Merck Veterinary Manual)

Senior Horses

A senior with good teeth may still manage an ordinary forage-based diet.

A horse with worn, loose or missing teeth may require:

• Soaked forage pellets

• Soaked hay cubes

• Beet pulp

• A complete senior feed

• Several smaller wet meals

A complete feed may replace long-stem forage, but it must be fed at the manufacturer’s recommended rate and divided into several meals. (Merck Veterinary Manual)

Growing Horses

Growing horses need controlled energy along with properly balanced:

• Protein

• Lysine and other amino acids

• Calcium and phosphorus

• Copper and zinc

• Vitamins

Straight grain is not a complete growth ration. Excess calories and rapid weight gain can be as harmful as underfeeding.

Pregnant and Lactating Mares

Late pregnancy and lactation increase energy, protein and mineral requirements.

A properly formulated broodmare feed is usually more appropriate than simply increasing oats or corn because the mare needs far more than calories alone.

Horses With PSSM or Recurrent Tying-Up

Some horses with polysaccharide storage myopathy or recurrent exertional rhabdomyolysis benefit from a low-starch ration with fat used as an alternative energy source.

The amount of fat and starch should be based on diagnosis, body condition and exercise rather than a generic “muscle feed” recommendation. (Merck Veterinary Manual)

Horses With Equine Metabolic Syndrome

Horses with equine metabolic syndrome or insulin dysregulation require much stricter management.

Current Merck guidance recommends eliminating grain, grazing and sugary treats for horses with EMS and providing tested low-NSC forage under a controlled plan. These horses should not receive an ordinary grain-based ration simply because it is labelled “performance” or “senior.” (Merck Veterinary Manual)

How Worried Should You Be?

Lower Risk

The horse:

• Maintains a healthy body condition

• Receives most of the ration as forage

• Has small, weighed concentrate meals

• Has no history of ulcers, laminitis or digestive disease

• Has continuous water access

• Is eating the correct product at the labelled rate

What to do: continue monitoring body condition, manure, appetite and workload.

Moderate Risk

The horse:

• Receives two fairly large concentrate meals daily

• Is fed by scoop rather than weight

• Goes several hours without forage

• Bolts the concentrate

• Is gaining weight

• Has not had the ration reviewed recently

What to do: weigh every meal, calculate it as a percentage of body weight and divide the daily ration further where possible.

High Risk

The horse:

• Receives more than 0.5% of body weight in one grain-based meal

• Has a previous history of laminitis or gastric ulcers

• Is obese or insulin dysregulated

• Receives a sudden concentrate increase

• Is fed a high-starch ration with little forage

• Develops recurrent loose manure or post-feeding discomfort

What to do: stop increasing the feed and arrange a veterinary or equine nutrition review.

Critical

The horse:

• Has gained unrestricted access to grain

• Has eaten an unknown large quantity

• Develops colic, watery diarrhoea or marked depression

• Has hot painful feet or strong digital pulses

• Becomes reluctant to walk

• Has feed or saliva coming from the nostrils

• Becomes weak or collapses

What to do: call a veterinarian immediately.

When Is Concentrate Feeding an Emergency?

Sudden Grain Overload

A horse breaking into a feed room or grain bin is an emergency even when the horse still appears normal.

The risk depends on:

• Type of feed

• Quantity eaten

• Horse size

• Previous ration

• Time since ingestion

• Metabolic health

Clinical signs can be delayed while hindgut acidosis and inflammatory changes are already developing.

Do not wait for the horse to start rolling or become lame before calling.

Colic or Severe Diarrhoea

Call urgently for:

• Repeated pawing

• Flank watching

• Rolling

• Sweating

• Abdominal distension

• Reduced or absent manure

• Profuse diarrhoea

• Depression

• Refusal to eat

Possible Laminitis

Warning signs include:

• Hot feet

• Strong or bounding digital pulses

• Short, pottery steps

• Reluctance to turn

• Shifting weight

• A rocked-back stance

• Refusal to walk

Grain overload is a recognised trigger for acute laminitis, and hoof changes can begin before dramatic lameness becomes obvious. (Merck Veterinary Manual)

Choke

Rapidly consumed dry concentrate can contribute to oesophageal obstruction, especially in horses with poor dentition, dehydration or a previous choke history.

Signs include:

• Green or feed-stained nasal discharge

• Excessive salivation

• Coughing

• Repeated gulping

• Neck stretching

• Sudden distress during eating

Remove all feed and water and call your veterinarian. Do not pour oil or water into the horse’s mouth. (Center for Equine Health)

What Should You Do After Accidental Grain Access?

1. Remove the horse from the feed source.

2. Call your veterinarian immediately.

3. Estimate which feed was eaten.

4. Estimate the maximum amount missing.

5. Record when access may have occurred.

6. Save the feed bag, label and batch number.

7. Keep the horse quiet.

8. Do not exercise the horse.

9. Do not administer oil, medication or other treatments unless directed.

10. Follow your veterinarian’s instructions regarding water and forage.

11. Monitor manure, behaviour and digital pulses.

12. Keep checking the feet for several days as directed.

The fact that the horse looks comfortable fifteen minutes after raiding the feed room does not mean the danger has passed.

What Else Can Cause Poor Condition or Performance?

Do not assume a horse needs more concentrate merely because they are thin, tired or performing poorly.

Important possibilities include:

• Insufficient forage

• Poor-quality forage

• Dental disease

• Gastric ulcers

• Parasites

• Chronic pain

• Respiratory disease

• Liver or kidney disease

• PPID

• Chronic intestinal disease

• Social competition at feeding time

• Excessive workload

• Poor saddle fit

• Inadequate protein or amino acids

• Mineral imbalance

• Poor semen or milk production demands in breeding animals

A ration review is important, but unexplained weight loss or performance decline also deserves a veterinary examination.

How to Build a Safer Concentrate-Feeding Plan

1. Establish the Horse’s Weight

Use a scale where available or a consistent weight-estimation method.

Do not calculate a ration from breed stereotypes or an owner’s heroic guess.

2. Assess Body Condition

Determine whether the horse actually needs:

• More calories

• Fewer calories

• More protein

• Better minerals

• A different forage

• Medical investigation

3. Weigh the Forage

Forage is the largest part of the ration and should not remain the least accurately measured part.

An average healthy horse commonly consumes around 2% to 2.5% of body weight in total dry matter daily, with at least half coming from forage. Individual needs vary with breed, work, health and body condition. (Merck Veterinary Manual)

4. Identify the Feed Category

Determine whether the product is:

• Grain

• Grain-based concentrate

• Ration balancer

• High-fibre performance feed

• Complete feed

• Forage substitute

5. Read the Feeding Directions

The manufacturer’s feeding rate is designed to deliver a certain amount of protein, vitamins and minerals.

If the labelled amount makes the horse overweight, select a more concentrated low-calorie product rather than feeding a tiny fraction of a high-volume feed and assuming the diet remains balanced.

6. Weigh the Concentrate

Do not feed by:

• Scoop

• Coffee tin

• Handful

• Bucket line

• “What we have always done”

Different feeds have very different densities. Weigh each new feed and write the correct scoop weight on the bin.

7. Calculate the Percentage of Body Weight

Divide the weight of one grain-based meal by the horse’s body weight.

Keep the result below 0.5%, and substantially lower where starch, metabolic disease or ulcer risk warrants it.

8. Ask for the Starch and Sugar Analysis

This is particularly important for:

• Ulcer-prone horses

• Insulin-dysregulated horses

• Horses with previous laminitis

• PSSM horses

• Easy keepers

• Horses eating large concentrate quantities

9. Split the Daily Quantity

Use enough meals to keep each portion comfortably below the maximum limit.

10. Feed Forage First

Offer hay before the concentrate and avoid large meals on an empty stomach.

11. Transition Over 10 to 14 Days

Increase the new feed gradually while reducing the old one.

12. Reassess the Horse

Monitor:

• Body weight

• Body-condition score

• Appetite

• Manure

• Behaviour after meals

• Digital pulses

• Performance

• Feed left behind

Review the ration whenever the workload, forage batch, health or body condition changes.

Common Concentrate-Feeding Mistakes

Treating the Maximum as the Goal

The 0.5% limit is a ceiling, not a target to reach at every meal.

Feeding by Scoop

A scoop of corn, oats and a light high-fibre pellet can differ dramatically in weight and calories.

Assuming Pellets Are Low in Starch

Pelleting changes the physical form, not necessarily the ingredients.

Underfeeding a Fortified Feed

A small handful of a product designed to be fed in kilograms may not provide enough vitamins, minerals or protein.

Adding Grain to an Already Balanced Commercial Feed

This increases energy and starch while diluting the carefully designed nutrient balance.

Making Abrupt Changes

A sudden change in feed type or quantity can disrupt the hindgut before the horse visibly appears unwell.

Giving a Large Meal Before Hard Work

Exercise does not make the digestive system suddenly safer for a starch-heavy meal.

Waiting After a Feed-Room Raid

Early veterinary intervention is far more useful than calling once colic or laminitis is obvious.

How Can Feed-Related Problems Be Prevented?

• Keep forage at the centre of the ration.

• Use concentrate only for an identified need.

• Select a product designed for the horse’s life stage and workload.

• Weigh every feed.

• Keep grain-based meals below 0.5% of body weight.

• Keep starch lower in ulcer-prone and metabolically sensitive horses.

• Divide large daily amounts into several meals.

• Feed forage before concentrate.

• Avoid long forage-free periods.

• Introduce changes over 10 to 14 days.

• Maintain clean water and salt.

• Keep feed dry and free from mould.

• Feed competing horses separately.

• Maintain dental care.

• Lock the feed room and secure every grain bin.

The feed-room door should not rely on the horse’s honesty. Horses have never signed that agreement.

Will My Horse Be Okay?

Most healthy horses do very well on an appropriately selected and carefully divided concentrate ration.

The outlook is best when:

• Forage remains the foundation

• The feed suits the horse

• Meals are weighed

• Starch is controlled

• Changes are gradual

• Body condition is monitored

• Early digestive signs are investigated

The prognosis after grain overload depends on how much was eaten, how quickly treatment begins and whether colitis or laminitis develops.

The safest concentrate meal is not the largest quantity the horse can tolerate.

It is the smallest amount that meets the horse’s actual nutritional requirements.

FAQs About Feeding Concentrate to Horses

How many pounds of grain can a 1,100-pound horse eat per meal?

The general upper limit is approximately 5.5 pounds of grain-based concentrate per meal. Many horses should receive considerably less, especially when the feed is high in starch.

How many times per day should concentrate be fed?

It depends on the daily quantity. Small amounts may be divided into one or two labelled servings, while larger rations should usually be divided into three or four meals approximately four to six hours apart.

Should hay be fed before grain?

Yes. Feeding forage before concentrate may slow gastric emptying and reduce the speed of the resulting hindgut pH change. It does not make an oversized grain meal safe. (OUP Academic)

Is pelleted feed safer than grain?

Not automatically. Some pellets contain substantial cereal starch, while others are high in fibre or designed as complete forage replacements. Check the ingredients, starch content and purpose statement.

Does every performance horse need grain?

No. Some performance horses maintain condition on forage plus fibre and fat-based feeds. Others doing intense work need more carbohydrate. The ration should match the actual workload and individual response.

Final Thoughts

Concentrate can be an important part of an equine ration, but it should remain a calculated supplement rather than the automatic centre of every meal.

The main rules are simple:

• Start with forage.

• Confirm that concentrate is genuinely needed.

• Know what type of feed you are using.

• Weigh every meal.

• Keep grain-based portions below 0.5% of body weight.

• Control the starch load.

• Divide larger daily amounts.

• Feed forage before concentrate.

• Introduce changes gradually.

• Treat accidental grain access as an emergency.

The question is not simply, “How many scoops should my horse get?”

It is:

What does this horse need, what is already being supplied by the forage, and how can the remaining nutrients be provided with the lowest reasonable digestive risk?

That is how concentrate becomes useful rather than dangerous.

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If you are unsure whether your horse’s concentrate meals are too large, too starchy or poorly matched to their workload, ASK A VET™ can help you organise the ration, body condition and feeding history before you finalise the plan with your veterinarian or equine nutritionist.