The Basics of Equine Nutrition: An Introductory Guide

Horse Education Online
2 days ago
5 min read

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 lifespan. Luckily, understanding the basics 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.

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

To feed a horse well, it helps to first understand how they process food. Horses are hindgut fermenters, meaning their large intestine—specifically the cecum and colon—is responsible for digesting fibrous material through fermentation. Unlike ruminants like cows, horses have a relatively small stomach that empties quickly. This is why grazing and small, frequent meals are so important.

In the wild, horses would graze for most of the day—up to 16 hours—consuming small amounts continuously. Modern feeding practices can disrupt this natural rhythm, leading to digestive problems if not managed thoughtfully. Conditions like ulcers, colic, or laminitis often trace back to abrupt dietary changes or feeding routines that don’t match their digestive design.

Key takeaways:

Horses have a small stomach and large fermentation-based hindgut.
They’re natural grazers, designed to eat little and often.
Sudden changes in diet can cause serious digestive issues.

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 correct amount isn’t just about avoiding waste—it’s about supporting health and preventing disease. Horses should be fed by weight, not volume, since different feeds have different densities. A scoop of oats doesn’t weigh the same as a scoop of pellets.

Monitoring your horse’s body condition score (BCS) is a simple but effective way to adjust feed over time. Most healthy horses should score between 4 and 6 on a 9-point scale. If your horse is too thin or overweight, reevaluate forage quality, feed type, and activity level.

Also, introduce any changes—whether it’s a new hay supplier or grain mix—gradually over 7–14 days to allow the gut microbes to adjust without stress.

Quick tips:

Feed by weight, not volume.
Monitor body condition and adjust accordingly.
Make changes gradually to avoid digestive upset.

Common Feeding Mistakes to Avoid

Even with the best intentions, it’s easy to make nutrition missteps. Overfeeding grain is one of the most common mistakes, especially for horses in light work. Too much starch can overload the small intestine and ferment in the hindgut, leading to colic or laminitis.

Neglecting water or offering poor-quality hay are also common issues that can compromise your horse’s health. Finally, irregular feeding times can create stress, increasing the risk of ulcers and behavioral issues.

Avoid these pitfalls:

Don’t overfeed grain—match intake to workload.
Avoid poor-quality or moldy hay.
Maintain a regular feeding routine.
Ensure constant access to fresh, clean water.

Self-Assessment Quiz

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

____ Horses are ruminant animals like cows.
____ Horses are designed to eat small amounts continuously throughout the day.
____ Fats provide a safe, digestible energy source for horses.
____ Overfeeding grain can increase the risk of colic and laminitis.
____ Horses on pasture usually need more vitamin supplements than horses on hay.
____ Horses should be fed by volume, not by weight.