Getting weight onto a hard-keeping horse is a constant battle. You increase the grain, but the horse gets hot or the digestive system protests. The solution isn’t more starch—it’s a strategic calorie source that delivers energy without the metabolic risks. The right grain or supplement provides dense, cool energy from fat and fiber, targeting body condition without the behavioral issues.
I’m Mohammad Maruf — the founder and writer behind Drink4Good. I analyze equine nutrition products through the lens of ingredient quality, fat-to-starch ratios, and real-world user outcomes for hard-keepers and senior horses.
After sifting through dozens of feeding trials and customer reports, this guide breaks down the most effective options for finding the very best grain for horses to gain weight safely and consistently.
How To Choose The Best Grain For Horses To Gain Weight
Selecting a weight-gain grain or supplement for horses requires looking past marketing claims and focusing on three pillars: calorie source, digestibility, and metabolic impact. Starch-heavy grains can cause insulin spikes and behavioral heat, while high-fat products deliver sustained energy.
Fat Content and Calorie Density
The most effective weight-gain products for horses derive calories from fat rather than sugar or starch. Look for a guaranteed analysis showing at least 20% crude fat, with premium options hitting 50% or higher. Fat provides more than twice the calories of an equal weight of carbohydrates, meaning you can feed less volume for the same caloric impact.
Ingredient Profile for Hard Keepers
Horses that struggle to maintain weight—seniors, rescue cases, and high-performance athletes—benefit from ingredients like stabilized rice bran, extruded soybeans, and flaxseed meal. These sources provide essential fatty acids that support coat and hoof health alongside the calorie boost. Products with added probiotics or prebiotics help maximize nutrient absorption in sensitive digestive systems.
Feeding Form and Palatability
If a horse won’t eat it, the calorie content means nothing. Powders, crumbles, and liquids each have different acceptance rates. Crumbles and powders mix easily into existing rations, while liquid oils can be drizzled over feed. Always verify that the form matches your horse’s feeding preferences to ensure consistent intake.
Quick Comparison
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| Model | Category | Best For | Key Spec | Amazon |
|---|---|---|---|---|
| Manna Pro Cool Calories 100 | Dry Fat Supplement | Seniors and hard keepers | 99% Fat Content | Amazon |
| Formula 707 Weight Gain Crumble | Calorie-Rich Crumble | Muscle building and weight support | High-quality protein & veg fat | Amazon |
| Pennwoods Body Builder 4000 | High-Fat Conditioner | Topline and body conditioning | High fat, low sugar/starch | Amazon |
| Farnam Weight Builder | High-Fat Powder | Consistent weight maintenance | 50% Crude Fat | Amazon |
| DAC Oil Gallon Jug | Liquid Oil | Coat and joint health plus weight | Fish oil & Vitamin E | Amazon |
| Horse Guard Super Weight Gain | 3-in-1 Supplement | Senior and rescue horses | Extruded soy, probiotics, vitamins | Amazon |
| Biotin Plus Supplement | Hoof & Coat Tablet | Hoof and coat health support | Biotin (Vitamin B7) | Amazon |
In‑Depth Reviews
1. Manna Pro Cool Calories 100 – 8 lb Bag
Manna Pro Cool Calories 100 is essentially pure fat at 99%, delivering over twice the caloric density of carbohydrates. This makes it the most concentrated calorie source on this list, requiring only a small daily scoop to move the needle on body condition. The “cool” energy profile means it won’t trigger the starch-induced hyperactivity that plagues many grain-fed horses.
Users consistently report visible results on older hard-keepers and Thoroughbred crosses that previously struggled to hold weight. The supplement is highly palatable, mixing easily into feed without causing refusal. Fatty acid content also drives visible improvements in coat shine and hoof health, as noted by multiple long-term reviewers.
With a 36-year-old horse thriving on it and a TB mare maintaining stable weight without heat, this supplement proves its value for both longevity and performance. The 8-pound bag provides a solid run at a feeding rate of roughly one scoop per day.
Why it’s great
- 99% fat provides the highest calorie concentration
- No added sugar or starch prevents metabolic upset
- Dramatically improves coat and hoof condition
Good to know
- Competitive pricing per pound of fat
- Some horses may need time to adjust to the texture
2. Formula 707 Weight Gain Crumble – 7 lb Bag
Formula 707 Weight Gain Crumble from John Ewing Company brings over seven decades of equine nutrition expertise into a calorie-rich crumble. Unlike many pellet-style feeds, these are crumbles—a texture that picky eaters often prefer. The formula combines digestible vegetable fat with high-quality protein to support both weight gain and muscle tone.
Customers report that even the fussiest horses eat these crumbles like treats. The fiber component helps maintain steady digestion, a critical factor when adding calories to a horse’s diet. Senior miniatures and older horses that had been underweight for years showed measurable improvement within weeks of starting this feed.
Manufactured in Colorado with consistent quality control, this supplement offers a balanced approach: calories for weight alongside amino acids for topline and condition. It’s a strong mid-range option that bridges the gap between pure fat supplements and complete feeds.
Why it’s great
- Highly palatable crumble texture reduces feed refusal
- Protein supports muscle development alongside weight gain
- Trusted brand with 75+ years of equine nutrition history
Good to know
- Contains some starch; monitor hot horses
- Lower fat percentage than pure fat supplements
3. Pennwoods Body Builder 4000 – 12 lb
Pennwoods Body Builder 4000 is formulated specifically for horses that need topline and body conditioning without the inflammatory effects of sugar and starch. This family-owned Pennsylvania brand uses locally sourced ingredients to create a calorie-dense powder that targets the very muscles and fat deposits that show in the withers and loin.
Users feeding two scoops daily to both young and old horses noted steady improvements in hair coat, hoof quality, and body mass. The formula’s concentrated energy source from fat rather than starch makes it ideal for performance horses during training or competition seasons when calorie demands spike.
With a flexible feeding rate that adjusts to workload and condition goals, the 12-pound bag gives owners room to customize. The manufacturer backs it with a one-year warranty, adding a layer of confidence for owners trying a new supplement for the first time.
Why it’s great
- Designed specifically for topline development
- No excess sugar or starch for metabolic safety
- Large 12-pound bag offers extended use
Good to know
- Priced higher per pound than basic fat supplements
- Works best as part of a complete feeding program
4. Farnam Weight Builder – 7.5 lb
Farnam Weight Builder packs 50% crude fat into a lightweight powder that mixes seamlessly with any grain ration. The calorie density means you feed less volume than you would with conventional grain, reducing the risk of digestive overload. With no added sugar, it’s a safe calorie source for horses with insulin sensitivity concerns.
Omega-3 fatty acids from flaxseed meal and heat-stabilized rice bran deliver a dual benefit: weight gain plus a glossy coat and healthy skin. Users report that a 22-year-old mare maintained stable weight year-round with this supplement, adjusting the dose seasonally to match metabolic changes.
The 30-day supply at a 4-ounce daily serving makes this a straightforward addition to any feeding routine. The calming energy profile supports performance horses without the nervous energy that starch-heavy feeds can produce.
Why it’s great
- 50% fat for efficient calorie delivery
- Omega-3s improve coat and skin health
- No sugar added for metabolic safety
Good to know
- Requires consistent daily feeding for best results
- Alfalfa flavor may not suit all palates
5. DAC Oil Gallon Jug – Horse Weight Gain Supplement
DAC Oil delivers calories in liquid form, providing a different feeding option for horses that are picky about powders or crumbles. The fish-oil base supplies essential fatty acids that support joint health, skin condition, and digestive regularity alongside the calorie boost. Vitamin E helps preserve the oil’s integrity and supports immune function.
Users saw results beyond weight, with improvements in stiff joints and itchy skin. The liquid format allows precise dosing and easy mixing, though a quality pump is recommended to avoid leaks and waste. One reviewer noted it helps with constipation in older horses, adding a digestive benefit.
The gallon size offers good value for multi-horse operations. Horses accept it readily, with owners calling it a repeat purchase for keeping Gypsy geldings and senior horses looking their best.
Why it’s great
- Liquid form for easy mixing with any feed
- Fish oil benefits joints and skin
- Vitamin E supports immune health
Good to know
- Requires a pump for clean dispensing
- Fish flavor may not suit all horses
6. Horse Guard Super Weight Gain – 10 lb
Horse Guard Super Weight Gain takes a three-pronged approach: full-fat extruded soybeans for calorie density, prebiotics and probiotics for digestive efficiency, and a vitamin-mineral package for overall health. This makes it a comprehensive weight-building solution rather than a single-nutrient booster. The extrusion process makes the soy more digestible than raw or roasted forms.
Owners of senior horses and rescue cases report this as the most effective product they’ve tried, with visible results appearing faster than with standard feeds or oils. The added Vitamin E—1,500 IU per dose—supports immune recovery in stressed or transitioning horses. The included scoop simplifies dosing at about 8 ounces per day for a typical 1,000-pound horse.
Storage matters with this product: the bag can go stale if left in direct sun or stored too long. However, the science-backed formulation from a company founded in 1978 gives it credibility for long-term use.
Why it’s great
- 3-in-1 formula addresses weight, digestion, and immunity
- Extruded soy provides highly digestible protein and fat
- Probiotics maximize nutrient absorption
Good to know
- Bulky feeding rate may leave unfinished portions
- Bag must be stored cool and dry to prevent staleness
7. Biotin Plus Supplement – 5 lb
Biotin Plus is a targeted supplement for hoof and coat health rather than a direct weight-gain feed. It provides 20 mg of biotin per serving, along with other nutrients that support keratin production. While it won’t pack on pounds like a high-fat supplement, improved hoof integrity and coat quality are often secondary goals when managing overall condition.
Users report visible results within weeks, with increased mane and tail growth and a radiant shine at half the recommended dose. The unflavored tablets have a sweet scent that horses find appealing, making administration straightforward. Farriers frequently recommend this product for horses on minimal grain diets who need extra hoof support.
This supplement works best as part of a complete weight-gain program rather than a standalone solution. Owners should verify that their feed doesn’t already contain high biotin levels to avoid over-supplementation.
Why it’s great
- Effective for hoof growth and coat health
- Farrier-recommended for pasture horses
- Pleasant scent improves horse acceptance
Good to know
- Not a calorie-dense weight gain product
- Consult vet to avoid biotin overload
FAQ
How fast will a horse gain weight on a high-fat supplement?
Can I feed a high-fat supplement to a horse with metabolic issues?
What is the difference between cool calories and hot calories in horse feed?
Should I use a powder, crumble, or liquid supplement for my hard keeper?
How many pounds of weight-gain supplement should I feed per day?
Final Thoughts: The Verdict
For most owners, the grain for horses to gain weight winner is the Manna Pro Cool Calories 100 because its 99% fat content delivers the highest calorie concentration without starch or sugar, making it both effective and metabolically safe. If you need a more complete nutritional package with digestive support, grab the Horse Guard Super Weight Gain. And for a budget-friendly crumble that horses love, nothing beats the proven Formula 707 Weight Gain Crumble.