Watching a mare struggle to keep condition while nursing a fast-growing foal tugs at any horse owner’s heart. The right nutritional support can mean the difference between a thriving pair and a cascade of health setbacks that take months to undo.
I’m Mo Mahin — the founder and writer behind Furric. After digging into veterinary nutrition protocols, analyzing ingredient safety standards across dozens of equine feed labels, and listening to firsthand accounts from seasoned breeders and rescue owners, I’ve built a clear picture of what actually works.
Whether you are preparing for a first foaling or managing a hard-keeper mare, this buying guide cuts through the noise to help you choose with confidence. Discover the ideal nutritional support for nursing mares and growing foals with our expert-curated selection of the absolute best mare and foal feed.
How To Choose The Best Mare And Foal Feed
The nutritional demands on a mare during gestation and lactation are enormous, and a growing foal’s skeletal and immune systems depend on precise ratios of minerals, vitamins, and protein. Choosing the wrong supplement can lead to developmental issues or metabolic stress. Here is what matters most.
Life-Stage Specific Formulas
A feed designed for maintenance horses will not support a lactating mare or a weanling. Look for supplements that explicitly target gestation, lactation, or early growth. These products deliver elevated calcium, phosphorus, vitamin E, and selenium levels that plain grain mixes simply cannot match.
Calcium-to-Phosphorus Ratio
Skeletal development in foals hinges on a balanced calcium-phosphorus ratio — ideally around 2:1. An imbalance can trigger growth abnormalities or joint issues. Reputable mare and foal supplements always list these values upfront, so you can verify the math before feeding.
Pellet Versus Powder Delivery
Some horses are picky about texture. Pellets tend to be more palatable and reduce waste, while powders can be mixed into existing feed for finicky eaters. If your mare or foal has a sensitive digestive system, a pelleted supplement often provides more consistent intake per serving.
Quick Comparison
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| Model | Type | Best For | Key Feature | Amazon |
|---|---|---|---|---|
| Horse Guard Super Weight Gain | Weight Gain | Underweight mares & rescues | 3-in-1 with probiotics & extruded soy | Amazon |
| Farnam Mare Plus | Gestation/Lactation | Pregnant & nursing mares | Complete vitamin-mineral for fetal support | Amazon |
| Farnam Grow Colt | Foal Growth | Young foals & weanlings | 27 nutrients for bone & immune health | Amazon |
| Formula 707 Daily Essentials | Ration Balancer | All-life-stage supplementation | Proteinated trace minerals for absorption | Amazon |
| Purina Layena+ | Layer Feed | Backyard hen nutrition | Omega-3 enriched for egg quality | Amazon |
In-Depth Reviews
1. Horse Guard Super Weight Gain 10 lb
When a mare drops condition fast or a rescue foal arrives thin and depleted, you need a supplement that delivers measurable weight gain without upsetting digestion. Horse Guard Super Weight Gain combines full-fat extruded soybeans, prebiotics, probiotics, and a potent vitamin-mineral package into one dense 10-pound bag. It is purpose-built for hard keepers, seniors, and recovering horses who cannot afford to lose another pound.
The 3-in-1 formula addresses three weak points simultaneously: caloric density from the extruded soy, gut health from the probiotic blend, and immune defense from 1,500 IU of vitamin E per serving. Longtime users report visible improvements in topline and coat shine within weeks. One verified owner described it as the only product that helped their senior horse regain weight after a stressful interstate move, while another saw dramatic changes in an OTTB that dropped weight at the slightest stress. The scoop makes dosing straightforward — roughly 20 servings per bag for a 1,000-pound horse.
If you manage a mare that struggles to hold condition through lactation or a weanling that needs extra density, this is the supplement that delivers consistent, safe results. The only catch is that the bag should be stored in a cool, dark spot to keep the oils from going stale. For the peace of mind that comes with a proven track record since 1978, Horse Guard earns the top spot.
Why we love it
- Visible weight gain reported within weeks
- Probiotics support sensitive digestive systems
- Extruded soy improves coat shine and skin health
Good to know
- Large serving size may not be fully finished by picky eaters
- Effectiveness declines if bag is exposed to heat or sun
2. Farnam Mare Plus Gestation & Lactation Supplement
A pregnant mare has zero room for nutritional shortcuts — her body is building a foal while maintaining her own condition. Farnam Mare Plus is formulated specifically for the last trimester and lactation, delivering a dense array of vitamins, minerals, and amino acids that support fetal development and milk production without overcomplicating your feeding routine.
The 7.5-pound bag provides a 60-day supply in easy-to-feed pellets, which most horses accept readily. The guaranteed analysis shows 6% calcium and 4% phosphorus — a solid 1.5:1 ratio that supports proper bone formation in the developing foal. Experienced breeders noted that their mares stayed fat and healthy through pregnancy, and one owner of a 20-year-old pregnant mare confirmed that the fetus was not absorbed and the pregnancy progressed normally. Another buyer who fed it through both gestation and lactation said the foal loved sneaking bites too.
For owners who want a straightforward, stage-specific supplement that keeps a broodmare in top shape from breeding through weaning, this is a reliable choice. It blends seamlessly into a normal diet without fuss. A few international buyers mentioned packaging could be sturdier for shipping, but the product itself earned consistent praise across dozens of verified feedings.
Why we love it
- Targeted support for late gestation and nursing
- Balanced calcium-phosphorus ratio for foal bone health
- Pellet form reduces waste and increases palatability
Good to know
- Some buyers reported torn bags during shipping
- Not intended as a complete feed — must complement forage
3. Farnam Grow Colt Supplement
Foals grow at an astonishing rate, and any gap in nutrition during those first years can lead to permanent structural issues. Farnam Grow Colt is built around the specific demands of young horses, delivering 27 key nutrients — including protein, amino acids, vitamins, and minerals — that support consistent growth, connective tissue development, and immune function.
The pellet form makes it easy to mix with creep feed, and the balanced calcium-phosphorus ratio helps protect developing joints. Real-world feedback from owners is compelling: one rescued a pregnant mustang mare and used Grow Colt alongside quality forage to keep the foal growing at 0.1 hand per month. Another owner took a thin, sickly 6-month-old killpen colt and saw dramatic muscle development and height gains within weeks of starting one scoop daily. Even finicky foals accepted it after a light flavoring of apple juice.
If you are raising a foal from a rescue background or simply want to ensure your youngster develops on track, this supplement fills the nutritional gaps that even good hay can leave open. The 30-day supply at the 3.75-pound size lets you test response before committing to a larger bag. Just inspect the container on arrival — a few shipments arrived with damaged lids.
Why we love it
- Specifically formulated for foal growth and bone development
- Works well with creep feed for sucklings
- Visible results reported in height and muscle tone
Good to know
- Some foals need a flavor enticement at first
- Container can arrive damaged during shipping
4. Formula 707 Daily Essentials Ration Balancer
Not every horse needs a heavy weight-gain supplement. For mares on good forage who just need a nutritional top-up, Formula 707 Daily Essentials delivers a concentrated vitamin-mineral package that supports overall health without adding unnecessary bulk. The 6-pound bag provides 48 servings, making it one of the most cost-efficient ways to balance a forage-based diet.
The standout feature is the use of proteinated trace minerals — these are designed to survive digestion and maximize absorption, which matters greatly for a lactating mare who is pulling minerals from her own reserves. Users who have relied on Formula 707 for decades report consistent results: shinier coats, stronger hooves, and better mood in mares. One 40-year veteran of the brand noted that a 16-year-old AQHA mare ate it readily and looked great on it. The oat-sized pellets are palatable and produce virtually no waste.
For budget-conscious owners who want a reliable, research-backed supplement that works across all life stages — including mares and foals — Formula 707 is a smart baseline. It does not target weight gain specifically, so underweight horses may need additional caloric support, but as a daily ration balancer it is hard to beat. Just be aware that the bag design could use better sealing for transit.
Why we love it
- Proteinated minerals for superior nutrient absorption
- Palatable pellets with minimal waste
- Proven track record since 1946
Good to know
- Not a complete feed — best used as a balancer
- Bag top may open during shipping without additional wrapping
5. Purina Layena+ Layer Hen Feed
On a diversified homestead, keeping laying hens on a high-quality feed is just as important as caring for your equine partners. Purina Layena+ is formulated to produce large eggs with 250 mg of omega-3 fatty acids per egg — five times the amount found in a standard store-bought egg — making it a standout choice for backyard flocks where egg quality matters.
The Oyster Strong System provides a consistent calcium source that supports thick, durable eggshells, reducing breakage and improving lay cycle longevity. Chickens in verified reviews thrived on this feed, producing eggs with dark yellow yolks and robust shells. One buyer with auto-reorder set up noted that their flock stayed healthy and productive on this ration. The 40-pound bag offers good value for keepers with multiple hens, and the pellet form minimizes sorting and waste.
While this feed is not designed for horses, it earns a place here for homesteaders who manage mixed livestock and want a single trusted brand for their poultry nutrition. If you keep both horses and chickens, Layena+ simplifies feed ordering without compromising on ingredient quality. Availability can be spotty during peak seasons, so stocking up when supply is steady is a smart move.
Why we love it
- Eggs contain 250 mg omega-3 per large egg
- Oyster Strong System supports thick shells
- Highly palatable pellet form
Good to know
- Frequently out of stock during high demand
- Delivery packaging can arrive damaged
Safety & Care Tips
Store Feed in a Cool, Dry Place
Vitamin potency, especially fat-soluble vitamins like A, D, and E, degrades quickly when exposed to heat, humidity, or direct sunlight. Keep all opened bags in a sealed metal or plastic bin inside a barn or shed that stays below 75 degrees. Stale feed loses nutritional value and may spoil, causing digestive upset.
Transition Slowly to Avoid Colic
Abrupt changes in feed can disrupt the delicate microbial balance in a horse’s hindgut, leading to colic or diarrhea. When introducing a new supplement — whether for a mare or foal — mix it with the current ration over a 7- to 10-day period, gradually increasing the new feed while decreasing the old. Watch for any signs of discomfort or feed refusal during the transition.
FAQ
Can I feed a mare supplement to a foal?
How soon should I start supplementing a pregnant mare?
What is the ideal calcium-to-phosphorus ratio for growing foals?
Can I mix multiple supplements together?
How do I get a picky foal to eat a new supplement?
Final Thoughts: The Verdict
For most horse owners managing both a mare and foal, the best mare and foal feed winner is the Horse Guard Super Weight Gain because it delivers reliable weight gain, digestive support, and immune defense in one dense formula. If you want specialized stage-specific nutrition for a pregnant mare, grab the Farnam Mare Plus. And for a young foal that needs targeted bone and immune support, nothing beats the Farnam Grow Colt.