Our readers keep the lights on and my morning glass full of iced black tea. As an Amazon Associate, I earn from qualifying purchases.7 Best Grain For Horses To Gain Weight | Calories Not Carbs Only

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Horse Guard combines full-fat extruded soybeans, a probiotic/prebiotic blend, and a comprehensive vitamin-mineral package into a single granule — no need to mix multiple supplements. The 10-pound bag provides roughly 20 servings for a 1,000-pound horse, and each dose delivers 1,500 IU of Vitamin E to support immune function during weight recovery. This is not just a calorie bomb; it is a digestive health intervention that addresses the root cause of poor condition in many hard keepers.

Owner reports consistently mention visible results on senior horses and ex-racehorses that had lost significant weight after a move or stress event. The extruded soy provides a highly digestible protein source that supports topline muscle, not just belly fill. One reviewer noted that a senior horse who drops weight every winter stayed in good condition through spring for the first time using this formula. The only common caution is storage — the bag should be kept in a cool, dry place to prevent the granules from going stale.

For anyone managing a rescue horse, a senior with chronic weight loss, or a hard keeper that burns through standard grain rations, this is the most complete single-bag solution. The probiotic support reduces the risk of digestive upset that comes with sudden calorie increases, making it a safer option for sensitive stomachs.

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Farnam’s Weight Builder hits the sweet spot of 50% crude fat, delivering more calories per ounce than an equal weight of grain. The alfalfa-flavored powder mixes easily into a standard ration and contains omega-3 fatty acids from flaxseed meal and heat-stabilized rice bran to support coat health alongside weight gain. The formula is designed for long-term maintenance — owners can adjust the serving size seasonally to keep weight steady without the boom-and-bust cycle that plagues many high-starch feeds.

Long-term users, some reporting six months or more of consistent use, highlight how the product helped their horses maintain condition through harsh winters. One owner of a 30-year-old mare credits Weight Builder for reversing age-related weight loss that no other supplement had managed. The absence of added sugar is a major advantage for horses with metabolic concerns or a tendency toward excitability — these are digestible fat calories that fuel performance without a behavioral spike.

The 30-day supply at a 4-ounce daily serving makes this a manageable commitment for owners who want predictable results. The powder form avoids the mess of liquid oils and gives you precise control over the calorie bump.

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Manna Pro’s Cool Calories 100 is essentially pure fat in a dry, scoopable form — 99% fat derived from rice bran that delivers more than double the energy of an equal weight of carbohydrates. This is the supplement you reach for when a horse needs concentrated calories but absolutely cannot handle the heat or fizziness of grain starch. The product was specifically developed for performance horses requiring cool, focused energy, but it has become a staple for senior and underweight horses because it reduces the total volume of feed needed.

Owner reports on older horses are particularly strong. One user maintained a 36-year-old mare at a healthy weight using this product for years. Another noted that a hard-keeping 16-hand gelding responded to two level scoops per day with a dramatically improved coat — shiny, silky mane and tail — without any sugar in the formula. The fatty acid profile also supports hoof growth and reduced inflammation, which multiple reviewers observed in their horses after switching from traditional grain.

Because the calorie density is extreme, you need much smaller volumes than standard grain. This makes it ideal for horses that get full quickly or have limited appetite. The dry form means no sticky oil mess in the feed room.

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Formula 707 has been in the equine supplement game since 1948, and the Weight Gain Crumble formula remains one of the most consistently praised products among owners of picky eaters and senior horses. The crumble texture — not a pellet — uses vegetable fat for easily digestible calories and adds high-quality protein for essential amino acids that support muscle development. The inclusion of dietary fiber helps maintain smooth digestive function, which is often compromised in older horses losing weight.

Reviewers frequently describe this as the “only thing that worked” after trying numerous other products. One owner who struggled for years to put weight on a senior horse saw a reliable improvement within weeks. Another noted that their mustang treats the crumble like a special reward and finishes every bite. The 7-pound bag is compact but calorie-dense enough to make a meaningful difference without requiring massive feed volumes.

The vegetable-based fat source makes this a good option for horses that react poorly to animal-based fats or soy. The crumble texture also works well for horses with dental issues who struggle with whole grains or hard pellets.

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DAC Oil is a liquid fish oil supplement fortified with Vitamin E, designed to deliver omega-3 fatty acids directly into the diet for weight gain, skin health, and joint support. The gallon jug provides a long-lasting supply — one owner reports it lasting over two months for two horses fed twice daily. This is not a complete feed replacement; it is a calorie-dense top dressing that you pour over existing grain rations to bump the fat content significantly without adding bulk.

Owner reviews highlight dramatic coat shine improvements and relief from stiff joints and itchy skin. One reviewer noted that the oil helped regulate constipation in senior horses, while another reported that their Gypsy gelding had never looked better. The fish flavor is generally well-accepted, but using a quality pump dispenser helps avoid mess and leakage. Because the oil is pure liquid fat, it provides a higher calorie-to-volume ratio than many dry supplements.

This is the right choice for owners who already have a solid grain base and need a calorie amplifier rather than a complete supplement. The Vitamin E content also supports immune function in horses undergoing recovery from illness or stress.

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SmartEquine’s CocoSun Oil combines coconut oil and sunflower oil to deliver a balanced profile of omega-3, omega-6, and omega-9 fatty acids in a soy-free, allergen-free liquid. This is a cool-calorie energy source — the medium-chain triglycerides in coconut oil are metabolized differently than long-chain fats, providing quick energy without insulin spikes. The sunflower oil adds natural Vitamin E, making this a dual-purpose supplement for weight gain and skin health.

Owners using this on horses with metabolic issues or Cushing’s disease report that the oil helped restore body condition without interfering with their management protocols. One reviewer described bringing a Cushing’s horse back to full health after four months of adding CocoSun to a low-starch diet. The oil pours smoothly and mixes easily, though the initial cost is higher than many other options. The soy-free base is a critical advantage for horses with known soy sensitivities.

For horses that need a clean, soy-free calorie boost and the anti-inflammatory benefits of a broad fatty acid spectrum, this is the premium option. The gallon size provides good value relative to the ingredient quality.

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CountryMax Whole Flax Seed offers the most cost-effective route to adding omega-3 fatty acids to a horse’s diet, but it requires a critical preparation step — the seeds must be ground before feeding to unlock the nutritional value. Whole flaxseeds pass through the digestive tract largely intact, so a coffee grinder or feed mill is necessary for proper absorption. At roughly 40% fat content, flaxseed provides a solid calorie boost alongside powerful anti-inflammatory effects that can reduce arthritis pain and sweet itch symptoms.

Owner reports are impressive for the price. One reviewer describes how two senior horses with prior injuries showed such significant improvement in soundness that the vet found minimal arthritis after two months — no injections or shoes required. Another noted that the seeds helped regulate thyroid function in a metabolic horse. The 10-pound bag lasts over two months for two horses fed twice daily, making this the most economical option on the list. However, owners should note that flaxseed may not produce dramatic weight gain on its own if the base diet is lacking calories.

This is the right pick for owners on a tight budget who are willing to do the extra step of grinding. The anti-inflammatory benefits are unique among this lineup and can reduce reliance on commercial joint supplements.