The Basics of Equine Nutrition: An Introductory Guide

Whether you’re caring for a seasoned show jumper, a beloved trail companion, or a young colt just learning the ropes, one truth remains: nutrition is the foundation of a horse’s health. A well-balanced diet influences everything from your horse's energy levels and coat condition to their immune system and long-term soundness. Luckily, understanding the basics of equine nutrition doesn’t require a science degree. In this guide, we’ll walk you through the essentials of feeding your horse, so you can feel confident in your daily care routine.

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Don't forget to take the self-assessment quiz at the end of this article. Our quizzes are designed to help you study and retain the information provided.

Understanding the Horse’s Digestive System

Credit: tributeequinenutrition

To feed a horse properly, it helps to understand how their digestive system works. Horses are classified as hindgut fermenters, meaning the majority of their digestion occurs in the large intestine, specifically in the cecum and colon. These sections of the gut are filled with beneficial microbes that break down fibrous plant materials through fermentation, releasing energy and nutrients the horse can absorb.

Unlike cows, which chew cud and have multi-chambered stomachs, horses have a single small stomach with limited capacity. It holds only about two to four gallons and begins emptying shortly after the horse eats. This is why they are naturally suited to grazing throughout the day, eating small amounts of forage over long periods.

In the wild, horses typically graze for up to sixteen hours a day. Their digestive systems evolved around this pattern. Modern feeding routines that involve two or three larger meals can disrupt this natural rhythm and cause serious issues if not managed thoughtfully.

Why Feeding Behavior Matters

When horses are fed infrequently or are given large, grain-heavy meals, several problems can arise:

• The small stomach can overflow, sending undigested starch into the hindgut where it does not belong.

• Sudden changes in feed or irregular feeding times can lead to microbial imbalances in the gut.

• Conditions such as gas colic, hindgut acidosis, ulcers, or laminitis may develop as a result.

Feeding dry hay without adequate water intake can further increase the risk of digestive upset. The type and timing of feed, hydration, and how quickly new feeds are introduced all play a role in gut health.

For horses recovering from gut-related issues or prone to inflammation, supplements such as glucosamine and capillary strength powder may offer additional support when used alongside proper nutrition.

You can also explore our guide on how to tell if a horse is sick, where digestive symptoms are often one of the first red flags that something is wrong.

Key Takeaways

• Horses have a small stomach and a fermentation-driven hindgut

• They are designed to eat small amounts frequently throughout the day

• Large meals and sudden dietary changes increase the risk of digestive problems

• Feeding should always prioritize forage, hydration, and consistency

The Six Nutrients Every Horse Needs

Just like us, horses require a balanced diet that includes water, energy, protein, fats, vitamins, and minerals. Each plays a vital role, and neglecting even one can throw the whole system out of balance.

1. Water

Water is often the most overlooked nutrient, yet it’s absolutely critical. It helps regulate body temperature, aids digestion, and keeps all internal systems running smoothly. A horse might drink anywhere from 5 to 15 gallons of water a day depending on the weather, workload, and type of feed.

2. Carbohydrates

The primary energy source for horses, carbs are found in forages (like hay and grass) and grains. Forage should always come first—it’s rich in fiber, which is crucial for proper gut function.

3. Protein

Proteins support muscle development, tissue repair, and enzyme production. The amount your horse needs depends on factors like age, growth, and work level. Young horses, lactating mares, and athletes need more than a retired pasture buddy.

4. Fats

Fat is a dense energy source that’s easy to digest and less likely to cause digestive upset than starches. Horses in heavy work or needing weight gain often benefit from added fats like vegetable oil or rice bran.

5. Vitamins

Vitamins help regulate everything from metabolism to immune function. Horses on fresh pasture usually get what they need naturally, but hay-only diets may require supplementation.

6. Minerals

Horses need both macro (like calcium and phosphorus) and trace minerals (like selenium and copper) to maintain bone health, nerve function, and more. Many horses benefit from a salt block or mineral supplement, especially if on a hay-only diet.

Summary bullets:

• Water should always be clean, fresh, and available.

• Forage provides essential carbohydrates and should be the diet's foundation.

• Protein needs vary by age and activity level.

• Fats are safe, concentrated sources of energy.

• Vitamins and minerals support internal systems and should be balanced carefully.

  
  

Forage: The Foundation of Equine Diets

Forage is more than just a filler—it’s the heart of a healthy diet. Hay and grass provide the bulk of the horse’s calories and the fiber needed for gut function. Horses should consume 1.5% to 2% of their body weight in forage daily. For a 1,000-pound horse, that’s 15 to 20 pounds of hay!

There are different types of hay to consider. Grass hays like timothy or orchard grass are lower in protein but perfect for most adult horses. Legume hays like alfalfa are richer in protein and calcium and are great for growing foals or lactating mares.

Things to remember:

• Forage should make up the majority of a horse’s diet.

• Choose hay based on the horse’s age, workload, and needs.

• Always inspect hay for mold, dust, or contaminants.

  
  

Feeding the Right Amount

Feeding the right amount is not just about reducing waste or cost—it plays a direct role in your horse’s metabolic balance, gut health, and long-term soundness. Too much feed can lead to obesity and insulin resistance, while too little can result in muscle loss, weakness, and poor hoof quality.

Feed by Weight, Not by Volume

One of the most common mistakes owners make is measuring feed by scoops or volume instead of weight. A scoop of oats, for example, is much lighter than a scoop of commercial pellets. Feeding by weight ensures that your horse gets a consistent and accurate nutrient intake every day, regardless of feed type.

To do this properly, use a small digital hanging scale or kitchen scale to weigh each type of feed you use, then calculate how much your horse should receive based on their body weight and workload. Most adult horses eat between 1.5 to 2.5 percent of their body weight in feed per day, depending on activity level and condition.

Monitor Body Condition Score

Body condition scoring is a simple but effective tool to track your horse’s weight and adjust feed accordingly. The 9-point system ranges from 1 (emaciated) to 9 (obese). A healthy horse typically scores between 4 and 6. Overweight horses are at increased risk for laminitis and metabolic disorders, while underweight horses may suffer from malnutrition, poor topline development, or underlying disease.

If you're unsure whether your horse’s weight is in the healthy range, consider reviewing our article on equine metabolic syndrome to understand how weight, insulin function, and feeding habits are interconnected.

Make All Feed Changes Slowly

Whether you're changing hay types, switching grain brands, or adding a supplement, all dietary changes should be introduced gradually over 7 to 14 days. This gives your horse’s gut microbes time to adjust and helps prevent colic, loose manure, or appetite loss.

Sudden changes in feed can shock the hindgut ecosystem, especially in horses that already have sensitive digestive systems or underlying lameness or recovery needs. To learn more about how subtle nutritional changes can affect your horse's movement and comfort, visit our equine lameness assessment guide.

Summary Tips

• Always measure feed by weight using a scale

• Monitor body condition regularly and adjust as needed

• Make changes gradually to protect digestive health

  
  

Self-Assessment Quiz: Equine Nutrition

Multiple Choice

1. What part of the horse’s digestive system is primarily responsible for fermenting fiber?

a) Stomach

b) Small intestine

c) Cecum and colon

d) Esophagus

2. How many gallons of water does a horse typically drink per day?

a) 1–2 gallons

b) 3–5 gallons

c) 5–15 gallons

d) Over 20 gallons

3. Which type of hay is typically higher in protein and calcium?

a) Timothy

b) Orchard

c) Alfalfa

d) Bermuda

4. What percentage of a horse's body weight should be fed as forage daily?

a) 0.5%

b) 1–1.25%

c) 1.5–2%

d) 3–4%

5. What is the ideal body condition score range for most horses?

a) 1–3

b) 4–6

c) 7–9

d) Any number, as long as the horse is eating

6. Why should new feed be introduced gradually?

a) Horses prefer new flavors

b) It prevents waste

c) Gut microbes need time to adjust

d) To increase feed intake

7. Which of the following is NOT a recommended feeding practice?

a) Feed at regular times

b) Change feed overnight

c) Offer clean water at all times

d) Inspect hay for mold

True or False

1. ____ Horses are ruminant animals like cows.

2. ____ Horses are designed to eat small amounts continuously throughout the day.

3. ____ Fats provide a safe, digestible energy source for horses.

4. ____ Overfeeding grain can increase the risk of colic and laminitis.

5. ____ Horses on pasture usually need more vitamin supplements than horses on hay.

6. ____ Horses should be fed by volume, not by weight.

   
   

Short Answer

1. Why is forage considered the foundation of a horse’s diet?

2. Name two reasons why fresh water is essential for horses.

3. List one example of a macromineral and one micromineral that horses need.

4. How does monitoring body condition score help in managing a horse’s nutrition?

   
   
   
   

Answer Key

Multiple Choice:

1. c) Cecum and colon

2. c) 5–15 gallons

3. c) Alfalfa

4. c) 1.5–2%

5. b) 4–6

6. c) Gut microbes need time to adjust

7. b) Change feed overnight

   
   

True or False:

1. F

2. T

3. T

4. T

5. F

6. F

Short Answer:

1. Forage provides essential fiber for digestion and mimics the horse’s natural grazing behavior.

2. To regulate body temperature and aid digestion (also acceptable: transport nutrients, prevent colic).

3. Macro: calcium, potassium, sodium; Micro: selenium, copper, zinc (any valid combo).

4. It helps determine if the horse is overweight or underweight and allows for dietary adjustments.

FAQ

How can I tell if my horse’s diet is actually working?

Beyond visible weight and energy levels, signs of a healthy diet include a shiny coat, good hoof quality, consistent manure, strong topline, and a willing attitude under saddle. If your horse is moody, fatigued, or prone to infections or digestive upset, their feed may be lacking key nutrients. Use a nutrition log and body condition scoring to track changes over time.

What are signs that a horse is overfed?

Common signs of overfeeding include weight gain, cresty neck, fatty deposits over the ribs or tailhead, and reduced motivation to work. Horses may also develop loose manure, behavioral changes, or increased risk for conditions like laminitis or equine metabolic syndrome. A diet review and exercise adjustment may be needed.

Should performance horses be fed differently?

Yes. Horses in intense work often require more calories, protein, electrolytes, and fat than maintenance horses. They may benefit from performance feeds, additional hay, and targeted supplements to support recovery, muscle repair, and stamina. However, feeding must still be forage-first and adjusted to workload and metabolism.

Can forage-only diets be balanced?

In some cases, yes—if the forage is high quality and the horse is in light work. However, many hays are deficient in key minerals like copper, zinc, and selenium. Even forage-only diets usually need a ration balancer or mineral supplement to meet nutritional requirements, especially in areas with known soil deficiencies.

Is it okay to feed treats like carrots or apples daily?

Yes, in moderation. Treats like apples, carrots, and bananas are generally safe, but limit portions to avoid excess sugar. Horses with metabolic issues or insulin resistance should avoid sugary fruits altogether and may be better suited to low-sugar treats like hay cubes or celery. Always introduce new treats slowly and observe your horse’s reaction.

How often should I reevaluate my horse’s feeding plan?

You should review your horse’s nutrition at least every six months or sooner if there’s a change in workload, weight, health status, or forage supply. Seasonal hay shifts, weather extremes, or changes in behavior are good prompts to revisit your feeding program and make necessary adjustments.