The infertile mare: solutions

There's nothing quite like watching a newborn foal find its legs for the first time. Getting there isn't always straightforward. Infertility in mares is frustrating precisely because it's rarely just one thing, and treating it well usually means working on several fronts at once, not chasing a single fix. Here's how we approach it in practice.

This is how you support an infertile mare

1. Treat underlying problems

Start with your mare's general health, not her reproductive tract. Have her examined and address any medical issues in consultation with your vet, who will look at correcting anatomic abnormalities and will usually treat infections with antibiotics first.

Laminitis, equine metabolic syndrome, arthritis: any of these need treating, and the pain needs managing, before you think about a covering date.

2. Create an optimal environment

Increase the chances of a successful pregnancy by giving your mare's stable a thorough going-over. Pay particular attention to her feed and her accommodation.

Make sure she gets enough exercise, because she shouldn't be overweight (or underweight, for that matter). Keep her stress as low as you reasonably can, and let her have contact with other horses if at all possible. Mares are herd animals first; isolation is its own kind of stress.

3. Adjust your mare's diet: before, during, and after gestation

The correct diet is crucial for mares in foal

Give her access to a paddock where possible. Grass carries nutrients that matter for both your mare and her embryo, and roughage alone won't supply enough minerals, vitamin E, or protein [2]. A forage balancer such as Este Balancer is built to close exactly that gap, topping up the vitamins and minerals a hay- or grass-based diet typically falls short on, without adding unnecessary calories.

Protein matters for the foal's growing cells and tissues, especially in the final months of gestation and right through lactation.

One thing worth saying plainly, because clients get this wrong constantly: being in foal is not a license to overfeed. If she's in good condition, her normal ration is enough for the first eight months of gestation.

Her nutritional needs don't really climb until the final three months, when the foal goes through a genuine growth spurt. Plenty of concentrated feeds on the market are built for exactly this increased energy demand, and vegetable oils are a healthier way to add calories than piling on sugar.

Nutrients that support fertility, and what the evidence actually shows

• Vitamin E. A deficiency affects fertility and has been linked to foal malformation (white muscle disease) and abortion. In a study of pregnant heavy draft mares, vitamin E and selenium supplementation before foaling shortened placental retention time and improved reproductive performance, and vitamin E given through lactation raises IgG and IgM in colostrum, which boosts the foal's own immunity [3][4].
• Broccoli. It's rich in indole-3-carbinol, a sulfur compound studied in humans for its effect on estrogen metabolism [5][6]. Nobody has run that exact trial in mares. What we do have is our own clinical work: in a trial with Ghent University's Faculty of Veterinary Medicine, mares given a broccoli sprout powder blend for three months produced more than one additional viable embryo per season on average, compared with their own previous seasons [7]. That's a mare result, not a borrowed one.
• Folic acid, vitamin B12, choline, and betaine. These support the methylation pathways involved in cell division and gene expression, work that matters enormously in a fast-growing embryo. Most of the underlying research is in rodents and sheep, not horses [8][9], so we're inferring rather than quoting an equine trial directly. Cysteine, a building block for the antioxidant glutathione, fits the same logic: a human study linked cysteine and related thiols directly to fertility parameters in subfertile couples [10].
• Linseed. It shifts the diet's omega-3 to omega-6 ratio, and there is a real equine study behind it, though on the stallion side: linseed-derived DHA improved frozen-thawed semen motility and membrane integrity in a controlled trial [11]. The mare side of the story, hormone balance and regular ovulation, is less directly tested, but the mechanism doesn't stop at the reproductive tract's door.

Want to give your mare a bit of extra support before her covering date? Fresh & Fertile is built around this nutrient group, to support the endometrium and hormonal balance. Start three months before her covering date and continue through the first trimester.

To help meet her rising energy needs, Grow & Glow supplies plant-based omega-3s (DHA from microalgae) without added sugar. Start during the final three months of gestation and continue through lactation.

None of this guarantees a foal. Infertility in mares rarely comes down to one cause, and some cases need more than diet and management, a repro specialist and a full hormonal work-up included. But treating the underlying health problems, tightening the environment, and giving her diet real support at the right time each move the odds in your favor. We wish you and your mare every success.