How To Feed a Horse Safely

How To Feed a Horse Safely

By Dr Duncan Houston

Feeding a horse sounds simple until you realise how many problems start in the feed room.

Colic, gastric ulcers, laminitis, obesity, poor performance, poor topline, weight loss, choke, dehydration, and metabolic disease can all be linked to how a horse is fed. Not because owners do not care, but because horse nutrition is often built around habits: a scoop of this, a flake of that, a feed brand someone at the yard likes, and pasture that changes every season.

The safest horse diet is not the fanciest one.

It is a forage-first diet matched to the horse’s body condition, teeth, workload, pasture access, metabolic risk, water intake, and actual feed weight.

Quick Answer

Most horses should be fed primarily forage, usually hay, pasture, haylage, or forage substitutes, with clean water, salt, and a balanced vitamin and mineral source. Current recommendations are that horses receive at least 1.5% to 2% of body weight in forage dry matter per day, adjusted to the individual horse, workload, body condition, and health status. (Merck Veterinary Manual)

Grain and concentrates should only be added when forage alone does not meet the horse’s needs. Large grain meals increase digestive risk, so concentrates should be weighed, split into smaller meals, and matched to the horse in front of you. (Merck Veterinary Manual)

Why Horse Nutrition Is Different

Horses are grazing animals with a digestive system designed for frequent forage intake.

They have a relatively small stomach for their body size. Merck Veterinary Manual notes that the equine stomach holds only about 2 to 2.5 gallons, or 8 to 10 litres, of food and water. Food passes through the stomach quickly, which suits a grazing animal that eats small amounts across the day. (Merck Veterinary Manual)

Horses also rely heavily on hindgut fermentation. The cecum and colon contain microbes that ferment fibre and produce energy-rich volatile fatty acids. That microbial system is sensitive to sudden diet changes, especially abrupt shifts in hay, pasture, grain, starch, or feeding schedule. Merck recommends making diet changes slowly over about 10 to 14 days to reduce disruption of microbial balance and digestive upset. (Merck Veterinary Manual)

Horses also do not have a gallbladder. Ohio State University explains that horses continually secrete bile from the liver into the small intestine to assist fat digestion. (College of Food Sciences)

The practical message is simple:

A horse is not designed for one or two large meals. They are designed for regular fibre intake, steady gut movement, clean water, and slow dietary change.

The Feeding Hierarchy

Before choosing supplements, oils, concentrates, or fancy feeds, start with the basics.

A safe horse diet should usually be built in this order:

1. Clean water

2. Forage

3. Salt

4. Vitamins and minerals

5. Protein quality

6. Extra calories only if needed

7. Supplements only when they solve a defined problem

This order matters.

Many horses do not need grain. Many do not need a “complete” feed. Many do not need six supplements. They need enough appropriate forage, clean water, salt, and a mineral-balanced ration.

The feed bucket should not be a lucky dip with molasses.

Forage Comes First

Forage should be the foundation of almost every horse diet.

That may include:

• Pasture

• Grass hay

• Lucerne or alfalfa hay

• Haylage

• Hay cubes

• Hay pellets

• Beet pulp

• Chopped forage

• Other high-fibre forage substitutes

For many horses, forage should make up the majority of the diet. Merck states that horses should receive at least 1.5% to 2% of body weight in forage per day on a dry matter basis. (Merck Veterinary Manual)

For a 500 kg horse, that is roughly:

Feeding target	Approximate forage dry matter
1.5% body weight	7.5 kg per day
2% body weight	10 kg per day

These are starting points, not fixed prescriptions.

An overweight pony with EMS risk, a lactating mare, a hard-working eventer, a senior with poor teeth, and a growing foal all need different adjustments.

The main rule is this:

Do not start by asking, “What hard feed should I add?”

Start by asking, “Is the forage appropriate, safe, and measured?”

Hay, Pasture, and the Problem With Guessing

Pasture intake is hard to measure. Hay is easier, but only if you weigh it.

A “flake” of hay means almost nothing. One flake can weigh twice as much as another depending on bale type, compression, forage species, moisture, and who pulled it off the bale like they were trying to start a fight with it.

Hay quality also varies enormously. A forage analysis can show energy, protein, fibre, minerals, sugar, and starch. University of Minnesota Extension notes that laboratory testing is the best way to determine hay quality. (University of Minnesota Extension)

Hay should be checked for:

• Mould

• Dust

• Musty smell

• Foreign objects

• Toxic weeds

• Excessive stemminess

• Poor palatability

• Suitability for the horse’s body condition and health

Green hay is not automatically safe. Pale hay is not automatically poor. Lucerne is not automatically bad. Grass hay is not automatically low sugar.

The test beats the guess.

Feeding Frequency and Gastric Ulcer Risk

Horses produce gastric acid continuously, even when they are not eating. Chewing forage produces saliva, which helps buffer stomach acid. When horses go long periods without forage, the stomach lining can be exposed to acid for longer.

AAEP notes that gastric ulcers affect up to 90% of racehorses and 60% of show horses, and feeding management is one of the major risk factors. Long gaps without feed, stall confinement, high-grain diets, and stress can all contribute. (AAEP)

That does not mean every horse needs ulcer medication.

It means feeding should aim to reduce long fasting periods where possible.

Useful strategies include:

• More frequent forage access

• Slow feeders where safe

• Smaller concentrate meals

• Less high-starch feed

• Turnout where appropriate

• Avoiding intense exercise on an empty stomach

• Treating ulcers with veterinary diagnosis and guidance

Omeprazole remains an important ulcer medication, but it should not be used as a substitute for fixing the management problem. Research on omeprazole and calcium is mixed: one study found 60 days of omeprazole did not change serum calcium or bone mineral density in young geldings, while another study found omeprazole reduced apparent calcium digestibility in Thoroughbreds. (ScienceDirect)

So the sensible approach is:

Use ulcer medication when needed, under veterinary guidance, and fix the feeding and stress factors that allowed the ulcer risk to build in the first place.

When Does a Horse Need Grain or Concentrate?

Some horses do need concentrates.

These may include:

• Performance horses in regular work

• Lactating mares

• Growing horses

• Hard keepers

• Seniors with poor teeth

• Horses that cannot maintain weight on forage alone

• Horses needing a complete feed because forage intake is limited

• Horses with higher protein or mineral requirements

But many horses do not need grain at all.

Idle horses, easy keepers, overweight horses, many ponies, many companion horses, and horses in light work often do well on forage plus a ration balancer or vitamin and mineral supplement.

The mistake is feeding grain because the horse “needs a meal.”

Often, what the horse actually needs is minerals, salt, and controlled forage, not extra calories.

How Much Grain Is Too Much?

If concentrates are needed, they should be weighed and split into small meals.

Merck advises that large amounts of grain-based concentrate should be divided into smaller meals spaced through the day, and warns against large grain meals before strenuous exercise, transport, stress, or in exhausted horses with poor gut motility. (Merck Veterinary Manual)

As a general safety ceiling, avoid feeding more than 0.5% of body weight in grain-based concentrate in one meal.

For example:

Horse body weight	Maximum grain-based concentrate per meal
400 kg	2 kg
500 kg	2.5 kg
600 kg	3 kg
1,000 lb	5 lb
1,100 lb	5.5 lb

This is not a target. It is a ceiling.

Many horses should receive far less, especially if they are overweight, insulin-dysregulated, laminitis-prone, lightly worked, or already getting rich pasture.

Ration Balancers: The Most Underrated Feed Room Tool

A ration balancer is designed to provide vitamins, minerals, and often protein or amino acids without adding significant extra calories.

University of Minnesota Extension describes ration balancers as feeds designed to provide trace minerals and vitamins without adding energy to the diet. (University of Minnesota Extension)

They are useful when a horse:

• Maintains weight on forage alone

• Does not need grain

• Is an easy keeper

• Is overweight

• Is in light work

• Needs minerals but not calories

• Is being fed less than the recommended amount of a fortified feed

This is a very common situation.

If a feed bag says a 500 kg horse needs 2 kg per day to receive the intended vitamins and minerals, but you feed one handful, your horse is not receiving the designed nutrient profile.

That is where a ration balancer often makes more sense.

Calcium, Phosphorus, and Mineral Balance

Minerals matter.

Calcium and phosphorus are especially important for bone, muscle, nerve function, growth, lactation, and long-term skeletal health. Merck notes that the total diet calcium-to-phosphorus ratio should be greater than 1:1, with a desirable ratio around 1.5:1. (Merck Veterinary Manual)

This matters when owners build diets from single ingredients.

For example:

• Corn is higher in phosphorus and low in calcium.

• Beet pulp and lucerne are higher in calcium.

• Bran is high in phosphorus.

• Growing horses are more sensitive to mineral imbalance.

• Broodmares and lactating mares have higher mineral demands.

If you are formulating a diet from individual ingredients, use a forage analysis and work with a vet or equine nutritionist.

A horse feed scoop is not a mineral calculator, despite its confidence.

Water Is the Most Important Nutrient

Water is not an optional side dish. It is the foundation of digestion, temperature regulation, circulation, sweating, gut movement, and feed intake.

Merck states that a 500 kg adult horse in minimal work typically drinks about 21 to 29 litres per day on a mixed hay and grain ration or pasture, and water intake may almost double when horses are fed only dry hay. Sweat, heat, lactation, and exercise increase water needs further. (Merck Veterinary Manual)

Water should be:

• Clean

• Fresh

• Easy to access

• Not frozen

• Checked daily

• Available in enough volume

• Accessible to lower-ranking horses

• Offered with plain water if electrolytes are added to another bucket

Inadequate water access can reduce feed intake and increase risk of impaction colic and other problems. (Merck Veterinary Manual)

If your horse is not drinking, do not just add more feed. Work out why.

Salt and Electrolytes

Most horses need daily salt.

Salt supports thirst, hydration, nerve function, muscle contraction, and electrolyte balance. Many horses do not consume enough from a salt block alone.

Plain salt can often be added to feed in measured amounts, while balanced electrolyte supplements are more useful when sweat losses are significant, such as during endurance work, heavy training, hot weather, transport, or competition.

If electrolytes are added to water, plain water should also be offered because some horses refuse flavoured or electrolyte water. Merck specifically recommends providing plain water alongside salt or electrolyte mixes in water. (Merck Veterinary Manual)

Do not give concentrated electrolyte paste to a horse that is dehydrated and not drinking without veterinary guidance. Electrolytes need water to be useful.

Body Condition Is Your Feeding Report Card

The diet should be judged by the horse, not by the feed room.

Body condition scoring helps you monitor whether the horse is too thin, ideal, or overweight. University of Minnesota Extension describes body condition scoring as assessment of fat deposits in six areas: neck, withers, behind the shoulder, along the back, ribs, and tailhead. The Henneke scale runs from 1 to 9, with 4 to 6 considered ideal and 7 to 9 overweight to obese. (University of Minnesota Extension)

Check body condition every 2 to 4 weeks.

Also monitor:

• Weight tape or scale weight

• Neck crest

• Topline

• Fat pads

• Hoof comfort

• Coat quality

• Manure

• Appetite

• Energy

• Water intake

• Performance

• Recovery after exercise

A good diet should produce a horse that is healthy, comfortable, appropriately conditioned, and able to do its job.

Not just shiny.

Shiny and obese is still obese.

Risk Framework: How Worried Should You Be?

Low Risk

This is usually lower risk if your horse:

• Has a body condition score around 4 to 6 out of 9

• Eats mostly good-quality forage

• Has clean water available at all times

• Has salt available

• Has a balanced vitamin and mineral source

• Receives little or no unnecessary grain

• Has normal manure

• Has no colic history

• Has no laminitis signs

• Maintains weight and performance

This horse may only need routine diet monitoring.

Moderate Risk

This becomes more concerning if your horse:

• Is gaining or losing weight

• Is fed by scoop or flake only

• Gets grain despite low workload

• Has inconsistent manure

• Has poor topline

• Has poor coat or hoof quality

• Has reduced appetite

• Has no clear mineral plan

• Has hay from changing suppliers

• Has pasture access that changes seasonally

• Has not had teeth checked recently

This horse needs a diet review before a small issue becomes a clinical problem.

High Risk

This is high risk if your horse:

• Is overweight or obese

• Has a cresty neck or fat pads

• Has a history of laminitis

• Has EMS, PPID, or insulin dysregulation

• Has recurrent colic

• Has repeated choke episodes

• Is losing weight despite eating

• Has poor teeth

• Is being fed large grain meals

• Has poor water intake

• Is fed mouldy, dusty, or inconsistent hay

This horse needs veterinary and nutrition guidance.

Critical

This is urgent if your horse:

• Has colic signs

• Is choking

• Has sudden laminitis signs

• Refuses to eat

• Is severely dehydrated

• Has severe diarrhoea

• Has grain overload

• Has neurological signs after salt or water restriction

• Is weak, collapsed, or severely depressed

This is not a feeding adjustment for next week. This is veterinary attention now.

When Is This an Emergency?

Call a vet urgently if your horse has signs of colic, choke, laminitis, severe dehydration, or grain overload.

Colic signs can include repeated pawing, looking at the flank, kicking at the belly, lying down, rolling, sweating, stretching as if to urinate, straining, abdominal distension, loss of appetite, depression, and reduced manure. (Merck Veterinary Manual)

Laminitis signs can include sudden lameness, strong or bounding digital pulses, heat in the hooves, reluctance to walk, a rocked-back stance, or severe foot pain. Severe cases can involve rotation or sinking of the coffin bone and may become life-threatening. (Merck Veterinary Manual)

Call a vet urgently if your horse has:

• Repeated rolling or severe abdominal pain

• No manure with discomfort

• Feed or saliva coming from the nostrils

• Repeated coughing while eating

• Sudden foot soreness

• Heat in the hooves

• Strong digital pulses

• Sudden refusal to eat

• Severe diarrhoea

• Weakness, collapse, or severe depression

• A known feed room break-in

• Large unexpected grain intake

Do not wait to “see how they go” with colic, choke, laminitis, or grain overload.

What Else Can Look Like a Nutrition Problem?

Not every weight, performance, or manure problem is caused by feed.

Important rule-outs include:

• Dental disease

• Gastric ulcers

• Parasites

• PPID

• EMS

• Insulin dysregulation

• Chronic pain

• Arthritis

• Poor farriery

• Liver disease

• Kidney disease

• Chronic infection

• Respiratory disease

• Poor saddle fit

• Poor herd access

• Another horse stealing feed

• Stress or travel

• Poor water intake

• Toxic plants

• Mouldy hay

• Sand ingestion

This is why “change the feed” is not always enough.

A horse losing weight may need dental work, bloodwork, ulcer investigation, parasite testing, pain management, or a different social feeding setup.

A horse gaining weight may need insulin testing, pasture restriction, hay analysis, and a weight-loss plan.

The feed matters. The horse matters more.

What Should You Do Next?

1. Weigh the Horse or Estimate Body Weight

Use a scale if available.

If not, use a weight tape or body weight equation. The exact number may not be perfect, but the trend is useful.

You cannot calculate forage, concentrate, medication, or weight change properly without a body weight estimate.

2. Body Condition Score the Horse

Assess the six key areas:

• Neck

• Withers

• Behind the shoulder

• Ribs

• Back

• Tailhead

Record the score every 2 to 4 weeks.

Do not judge from across the paddock. Put your hands on the horse.

3. Weigh the Hay and Feed

Weigh:

• Hay

• Haylage

• Concentrates

• Ration balancer

• Beet pulp before soaking

• Hay cubes

• Pellets

• Chaff

• Oil or fat sources

• Supplements if dose matters

Then write it down.

A scoop is only useful after you know what it weighs.

4. Check Forage Quality

Look for:

• Mould

• Dust

• Poor smell

• Heat

• Excessive stems

• Toxic weeds

• Rodent contamination

• Foreign objects

• Poor palatability

If the horse is metabolic, laminitis-prone, overweight, underweight, senior, pregnant, lactating, growing, or in serious work, strongly consider forage analysis.

5. Decide Whether Hard Feed Is Actually Needed

Ask:

• Is the horse maintaining weight?

• Is the horse in enough work to need extra calories?

• Is the horse overweight?

• Is the horse metabolic?

• Is the current hard feed being given at the correct recommended amount?

• Would a ration balancer make more sense?

• Is the horse missing calories, protein, minerals, or just routine?

Many horses need minerals, not grain.

6. Make Changes Slowly

Change hay, pasture, concentrates, and supplements gradually over about 10 to 14 days where possible. (Merck Veterinary Manual)

This is especially important when changing:

• Hay batch

• Pasture access

• Grain type

• Concentrate amount

• Beet pulp or fibre sources

• Fat supplementation

• Feeding frequency

The hindgut is not emotionally prepared for surprise menus.

7. Monitor the Response

After diet changes, monitor:

• Appetite

• Manure

• Water intake

• Weight

• Body condition

• Energy

• Hoof comfort

• Behaviour

• Performance

• Signs of colic

• Signs of laminitis

If the horse worsens, stop guessing and get veterinary advice.

Common Feeding Mistakes

Feeding by Scoop Forever

Scoops measure volume, not weight. Different feeds have different densities.

Forgetting That Pasture Counts

Pasture can provide huge calories and sugar, especially in easy keepers and metabolic horses.

Feeding Grain Because the Horse “Needs Something”

Many horses need minerals and salt, not grain.

Making Sudden Feed Changes

Abrupt changes can disturb hindgut microbes and increase digestive upset risk.

Relying on Supplements Before Fixing the Diet

A supplement cannot fix poor hay, no water, excessive grain, or uncontrolled pasture.

Ignoring Teeth

A horse cannot digest forage properly if they cannot chew it.

Overfeeding Easy Keepers

Ponies, donkeys, and thrifty horses often need fewer calories than owners expect.

Underfeeding Hard Keepers

Thin horses need diagnosis first, then a controlled plan with better forage, digestible fibre, fat, protein, and veterinary checks where needed.

Special Cases That Need Extra Care

Overweight Horses and Ponies

Overweight horses need controlled calories, weighed forage, pasture restriction, and monitoring for EMS and laminitis. For EMS horses, UC Davis recommends hay ideally below 10% NSC on a dry matter basis. (Center for Equine Health)

Senior Horses

Older horses do not automatically need senior feed. They need dental checks, body condition monitoring, and a diet texture they can actually chew and swallow.

Performance Horses

Performance horses may need extra energy, protein, electrolytes, and recovery support, but grain should still be fed carefully and split into safe meal sizes.

Foals and Growing Horses

Foals need balanced growth, not fast growth. Calcium, phosphorus, copper, zinc, protein quality, and steady energy intake matter.

Broodmares and Lactating Mares

Pregnancy and lactation increase requirements. The mare’s diet affects the foal before and after birth.

Donkeys and Mules

Donkeys and mules generally need less energy than horses of similar body weight and often do better on lower-energy, high-fibre diets. Merck notes that their nutritional requirements are not the same as horses. (Merck Veterinary Manual)

How To Prevent Nutrition-Related Problems

Good feeding is mostly boring consistency.

Do this:

• Feed forage first

• Weigh hay and hard feed

• Keep clean water available

• Provide salt daily

• Use a ration balancer when minerals are needed but calories are not

• Make feed changes over 10 to 14 days

• Avoid large grain meals

• Split concentrates into smaller meals

• Test hay for high-risk horses

• Body condition score every 2 to 4 weeks

• Check teeth regularly

• Use strategic parasite control

• Monitor manure and appetite

• Control pasture in easy keepers

• Watch for early laminitis signs

• Review the diet when workload, season, health, or hay batch changes

The best feeding plan is not static.

It changes with the horse.

Will My Horse Be Okay?

Most horses do very well when the basics are corrected.

A horse that is bright, eating, drinking, passing normal manure, maintaining ideal body condition, and moving comfortably may only need fine-tuning.

A horse that is overweight, footsore, colicky, losing weight, choking, not drinking, or changing manure needs more than a feed room adjustment. That horse needs a proper veterinary and nutrition review.

Nutrition is powerful because small daily habits build long-term health or long-term problems.

The good news is that many feeding problems are fixable once you stop guessing.

FAQs

How much hay should a horse eat per day?

Most horses should receive at least 1.5% to 2% of body weight in forage dry matter per day. For a 500 kg horse, that is roughly 7.5 to 10 kg of forage dry matter daily, adjusted to body condition, workload, pasture, and health status. (Merck Veterinary Manual)

Does every horse need grain?

No. Many horses in light work or maintenance condition do not need grain. They may do well on forage, salt, water, and a ration balancer or vitamin and mineral supplement.

How much grain is safe in one meal?

As a general safety ceiling, avoid feeding more than 0.5% of body weight in grain-based concentrate in one meal. For a 500 kg horse, that is about 2.5 kg, and many horses should receive much less.

Are ration balancers better than grain?

They are better when the horse needs vitamins, minerals, and protein support without extra calories. They are not a replacement for extra calories when a horse genuinely needs weight gain or performance energy.

What is the most important nutrient for horses?

Water. Without clean, accessible water, feed intake, gut movement, hydration, sweating, and recovery are all affected. A 500 kg horse in minimal work may drink around 21 to 29 litres per day, and more with dry hay, heat, lactation, or exercise. (Merck Veterinary Manual)

Final Thoughts

Horse nutrition is not about finding the perfect feed bag.

It is about building the right system.

Start with forage. Add clean water, salt, and a balanced mineral plan. Weigh what you feed. Keep grain meals small. Adjust for body condition, teeth, workload, age, pasture, and metabolic risk. Make changes slowly. Watch the horse, not just the bucket.

The safest feeding plan is the one that matches the horse in front of you.

Not the stable routine.

Not the scoop.

Not the label.

The horse.

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If you are unsure whether your horse needs more forage, less grain, a ration balancer, hay testing, pasture restriction, or a full nutrition review, ASK A VET™ can help you work through the diet and warning signs before a feeding habit becomes a health problem.