The daily grain ration for horses is not a fixed amount; it changes based on the horse’s weight, its workload, age, and whether it is gaining or losing weight. Generally, most horses get the majority of their diet from forage like hay or grass, and grain—or concentrate feed—is used to fill the gaps in their energy needs.
Basics of Horse Nutrition and Grain
Feeding horses correctly is vital for their health. Horses are designed to eat small amounts often. Their stomachs are small. They need forage first. Grain is added only when needed.
Why Do Horses Need Grain?
Forage (hay and grass) is the backbone of a horse’s diet. It keeps their digestive system working well. Horses need forage for gut health.
However, some horses need extra energy or nutrients that hay alone cannot provide. This is where recommended concentrate feed for horses comes in. Concentrates are often grains like oats, corn, or barley, or commercial mixed feeds.
- Energy Needs: Harder working horses need more calories.
- Nutrient Gaps: Some hay might lack certain vitamins or minerals.
- Weight Management: Very thin horses need extra help gaining weight.
- Age: Very old or very young horses might need easier-to-digest food.
Forage First Approach
Always remember this rule: A horse should eat 1.5% to 2.5% of its body weight in forage daily. This is the starting point.
Horse feeding guidelines for grain always emphasize forage intake first. If a horse is not eating enough hay, adding grain can cause serious digestive issues like colic.
Calculating Horse Feed Requirements
To figure out how much grain to feed a horse per day, you must first know how much the horse weighs. Guessing is risky.
Determining Horse Weight
You can estimate a horse’s weight in a few ways:
- Weight Tapes: These are easy to use. Wrap the tape around the horse’s heart girth (just behind the front legs). Read the weight shown.
- Weight Scales: This is the most accurate method.
- Formula Estimation: If you have the heart girth (G) and the body length (L) in inches, you can use a formula. The body length is measured from the point of the shoulder to the point of the buttock.
Formula for Weight (Pounds): $\text{Pounds} = (\text{Girth}^2 \times \text{Length}) / 330$
Once you know the weight, you can set a total feed goal.
Energy Needs Based on Workload
The amount of grain depends heavily on what the horse does. We measure energy needs using Maintenance (M), Light Work (L), Moderate Work (Mo), and Heavy Work (H).
| Work Level | Description | Daily Energy Needs (DE/day) |
|---|---|---|
| Maintenance (M) | Resting, walking only, light riding. | About 16.7 Mcal |
| Light Work (L) | Light riding, trail rides 1-3 times a week. | About 20 Mcal |
| Moderate Work (Mo) | Training, showing, or ranch work 3-5 times a week. | About 25 Mcal |
| Heavy Work (H) | Intense training, racing, or hard labor. | 30 Mcal or more |
A typical 1,000 lb horse eating only hay might get 15 Mcal per day. If it moves into Light Work, it needs 5 Mcal more. This extra energy usually comes from grain.
Safe Grain Limits for Horses
One of the most important concepts in feeding is knowing the safe grain limits for horses. Too much grain at once is dangerous. It can overwhelm the small intestine’s ability to digest starch. This undigested starch hits the large intestine, leading to gas, pain, and potentially deadly colic or laminitis.
Rule of Thumb for Concentrate Intake
- Maximum Grain Per Meal: A horse should generally not eat more than 0.5% of its body weight in grain in a single meal.
- Maximum Daily Grain: Most horses should not receive more than 1% to 1.5% of their body weight in total grain per day, especially if the grain is high in starch.
Example for a 1,000 lb Horse:
- Maximum grain per meal: 5 lbs (0.5% of 1,000 lbs)
- Maximum grain per day: 10 to 15 lbs (1% to 1.5% of 1,000 lbs)
If a horse needs more than 10 lbs of grain daily, the diet needs re-evaluation. You should switch some of the grain to high-quality hay or feed a very low-starch, high-fiber commercial feed.
Types of Grain for Horse Feed
Not all grains are the same. They have different energy levels, fiber contents, and starch levels. Choosing the right types of grain for horse feed is crucial.
Common Grains
Oats
Oats are the traditional horse feed. They are easy to digest compared to corn. They provide good energy but are bulkier than corn, meaning you feed more volume for the same energy.
- Pros: Highly palatable, good fiber content.
- Cons: Lower energy density than corn.
Corn (Maize)
Corn is very high in energy (calories). It is often used for horses that need to gain weight quickly or those in very heavy work. However, corn is very starchy.
- Pros: High energy.
- Cons: Highest risk of starch overload; must be fed in small amounts.
Barley
Barley is popular in some regions. It is often processed (crimped or rolled) before feeding to improve digestibility. It has less energy than corn but more than oats.
- Pros: Good energy, safer starch levels than corn if processed well.
- Cons: Can be hard to digest if not processed properly.
Commercial Feeds vs. Straight Grains
Many owners opt for commercially prepared feeds. These are often “complete” feeds that mix grains, proteins, vitamins, and minerals into a balanced pellet or textured mix.
Commercial feeds are often safer because:
1. The starch and sugar levels are controlled.
2. Essential vitamins and minerals are added to match the forage.
If you feed straight grains, you must supplement with a balanced vitamin and mineral mix. Feeding only oats and hay will lead to deficiencies over time.
How Much Grain to Feed a Working Horse
How much grain to feed a working horse depends entirely on how hard it works and how much energy the forage provides.
Assessing the Workload
Let’s look at a 1,100 lb horse in different categories:
1. Lightly Working Horse (Trail Riding Once a Week)
This horse probably meets most needs on high-quality grass hay (about 2% of body weight, or 22 lbs of hay). Grain might only be necessary to ensure mineral intake.
- Grain Needs: 0 to 2 lbs per day. This might just be a small ration balancer pellet instead of actual grain.
2. Moderately Working Horse (Training 4 Days a Week)
This horse needs extra calories to maintain condition and energy for training sessions. The hay provides about 18 Mcal. The horse needs about 24 Mcal total. That leaves 6 Mcal deficit.
If using sweet feed or a pelleted feed that contains about 1,300 calories per pound:
* Grain Needs: About 4 to 6 lbs per day, split into two meals.
3. Heavily Working Horse (Eventer or Racehorse)
These horses burn a lot of energy. They might need 30 Mcal or more daily.
- Grain Needs: This can easily reach 10 to 14 lbs per day, depending on the calorie density of the feed. This amount must be split into 3 or 4 small feedings to prevent digestive upset.
The Importance of Body Condition Scoring (BCS)
Use the Body Condition Score (BCS, scale of 1 to 9) to adjust grain. If the horse is losing weight on its current grain amount, slightly increase the grain (by 0.5 to 1 lb) and monitor for a week. If the horse is gaining fat, slightly decrease the grain.
Feeding Schedule for Horses
The feeding schedule for horses is almost as important as the amount fed. Horses thrive on routine. Their digestive systems are designed for constant grazing.
Split Meals Are Essential
Never feed a horse a large grain meal all at once. As noted, the limit is about 5 lbs per meal for a 1,000 lb horse.
Ideal Feeding Schedule:
- Minimum of 2 Meals Daily: If feeding concentrates, divide the total daily grain amount into at least two equal feedings (morning and evening).
- For High-Energy Diets: If a horse needs 12 lbs of grain daily, feed 4 meals of 3 lbs each.
- Hay Access: Ensure the horse has access to hay between grain meals. This keeps the gut moving and buffers the stomach acid.
Example Schedule (1,000 lb horse needing 6 lbs of grain):
| Time | Feed | Amount | Notes |
|---|---|---|---|
| 7:00 AM | Grain Mix | 3 lbs | Immediately followed by hay. |
| 10:00 AM | Hay | Free access | Constant foraging. |
| 4:00 PM | Grain Mix | 3 lbs | Immediately followed by hay. |
| Overnight | Hay | Free access | Essential for gut health. |
Weight of Grain Per Scoop for Horses
A common mistake horse owners make is measuring grain by volume (scoops) instead of weight (pounds). Scoops are inaccurate because different feeds have different densities.
The Weight of Grain Per Scoop for Horses varies widely:
- Rolled oats are lighter than pelleted feed.
- Sweet feed packed tightly weighs more than fluffy, dry grain.
Always use a reliable scale to weigh your grain. If you must use a scoop, weigh the feed in your specific scoop first to find the conversion factor for that particular product.
General Estimates (Use for guidance only; weigh your feed!):
| Feed Type | Approximate Weight per 1-Quart Scoop |
|---|---|
| Rolled Oats | 1.0 to 1.2 lbs |
| Sweet Feed (Textured Mix) | 1.4 to 1.8 lbs |
| Pelleted Feed | 1.5 to 2.0 lbs |
| Whole Corn | 1.8 to 2.0 lbs |
If your recipe calls for 4 lbs of sweet feed, and your scoop holds 1.5 lbs, you need about 2.6 scoops—not just 3 scoops. Always weigh to be safe.
Special Considerations for Different Horses
Calculating horse feed requirements involves more than just work level. Age and health status matter greatly.
Feeding Senior Horses
Older horses (over 20) often have dental issues or slower metabolism. They need calories, but their teeth might not chew long-stem hay well.
- Solution: Replace some grain with soaked hay pellets or senior feed. These are high in digestible fiber and easy to eat.
Feeding Growing Horses (Foals and Yearlings)
Young horses need protein and minerals for bone and muscle growth. They need concentrated energy, but their gut cannot handle large starch loads.
- Guideline: Feed small amounts of high-quality, low-starch concentrate frequently throughout the day. Focus on feeds designed for growth, which have higher protein and mineral balances.
Feeding Easy Keepers vs. Hard Keepers
- Easy Keepers (Tend to be overweight): These horses should get no grain unless their diet is severely lacking vitamins/minerals. Their energy should come from high-fiber, low-sugar forage. They often thrive on plain grass hay.
- Hard Keepers (Tend to be thin): These horses need dense energy sources. You can increase their grain ration safely up to the 1.5% body weight limit, provided you split the meals and ensure their forage intake is adequate.
Recognizing and Avoiding Grain Overfeeding
It is crucial to watch for signs of overfeeding grain in horses. Ignoring these signs can lead to health disasters.
Digestive Issues from Excess Starch
When too much starch reaches the hindgut, bacteria thrive and produce excessive acid.
- Colic: Spasmodic colic (gas or upset stomach) is common.
- Diarrhea: Loose manure is a direct sign that the hindgut is struggling to process what the small intestine passed on.
Metabolic Issues from Excess Calories/Sugar
If the total energy intake (forage plus grain) exceeds what the horse burns, the excess energy is stored as fat, or it can cause metabolic problems.
- Obesity: Visible fat deposits, especially cresty neck.
- Laminitis (Founder): A painful, serious inflammation of the hooves, often triggered by a sudden large grain meal or chronically high sugar/starch intake.
Signs of Overfeeding Grain in Horses: A Checklist
- Unexplained weight gain despite normal work levels.
- Unsettled gut behavior (frequent kicking at the belly, pacing).
- Dull coat or excessive shedding (can be linked to mineral imbalance from straight grain).
- Spike in energy or “fizz” followed by a crash.
- Manure that is consistently soft or watery.
If you see any of these, immediately reduce the grain ration by 25% and reassess the forage quality.
Fathoming the Role of Forage in Grain Rations
To safely feed grain, you must know how much energy your forage provides. This is where modern horse nutrition emphasizes testing.
Hay Testing Benefits
If you feed 20 lbs of hay per day, what is its energy content? If you don’t test, you are guessing.
- Testing Reveals: Calories (DE), protein, sugar (ESC/starch), and mineral levels.
- The Adjustment: If your hay is very high-quality (high energy), you might need to feed 25% less grain than planned. If the hay is low quality, you might need more grain.
Comprehending your hay analysis allows for precise calculation of the daily grain ration for horses.
Transitioning Feeds Safely
Never switch a horse’s feed abruptly, whether it is hay or grain. The microbes in the horse’s hindgut need time to adjust to new ingredients. A sudden change can cause severe digestive upset.
Transition Guideline (Applies to all feed changes):
- Day 1-3: Feed 75% Old Feed / 25% New Feed
- Day 4-6: Feed 50% Old Feed / 50% New Feed
- Day 7-9: Feed 25% Old Feed / 75% New Feed
- Day 10: Feed 100% New Feed
This slow transition period helps prevent digestive shocks.
Frequently Asked Questions (FAQ)
What is the maximum amount of grain a horse can safely eat daily?
Generally, a horse should not eat more than 1% to 1.5% of its body weight in grain per day, spread out over several meals. For a 1,000 lb horse, this means 10 to 15 lbs maximum daily, divided into at least two to four feedings.
Can I feed my horse only grain and no hay?
No, this is extremely dangerous. Horses are hindgut fermenters and require a constant supply of long-stem forage (hay or grass) to maintain gut health, prevent ulcers, and keep the digestive system moving properly. Grain should never replace forage.
What is the best grain for horses?
Oats are often considered the safest traditional grain because they have lower starch content than corn and are easily digestible. However, many modern, specialized pelleted feeds are often better because they are fortified with necessary vitamins and minerals, providing a more balanced diet than straight grains.
How often should I feed grain to a hard-working horse?
A hard-working horse that requires a large daily grain ration for horses should be fed at least three, and ideally four, small meals spaced evenly throughout the day to keep the digestive system functioning smoothly and minimize starch overload.
Does a mare in foal need grain?
A mare in the first two-thirds of pregnancy usually does not need grain if she has good pasture or hay. In the last trimester, or if she is in moderate work, a small amount of recommended concentrate feed for horses may be added to meet increased energy demands, always following the slow introduction guidelines.