Feeding the pregnant and nursing mare

A broodmare's diet barely changes for most of pregnancy, then her needs explode after she foals. Get the timing wrong and you under-feed when it matters most.

The most common feeding mistake we see in broodmares is people pouring grain into a mare the day her pregnancy is confirmed and then easing off once she gets big and uncomfortable in late pregnancy. That's almost exactly backwards. A mare's nutritional requirements barely move for the first seven or eight months of gestation, climb in the last trimester, and then jump dramatically the moment she foals and starts producing milk. Feed to that curve and you raise a healthy foal on a sound mare. Feed against it and you end up with an over-conditioned mare early and an under-fed, weight-losing mare exactly when she's nursing hardest.

For most of pregnancy, a broodmare is just a horse. Through the first two trimesters her energy and protein needs are essentially those of any mare at maintenance, and a horse in good flesh on good forage often needs little more than a ration balancer to cover vitamins and minerals. This is the forage-first principle at its purest, and everything in forage-first feeding as the foundation applies directly: build the diet on quality hay or pasture, and add concentrate only to fill real gaps. The goal in early and mid pregnancy is to keep the mare at a healthy body condition — somewhere around a 5.5 to 6.5 on the nine-point scale — neither thin nor fat. An overweight mare is a harder foaling and no favor to the foal.

The shift comes in the last trimester. Roughly 60 to 65 percent of fetal growth happens in the final three months, so from about month eight onward the mare's requirements for energy, protein, and especially the minerals that build bone start to rise. This is when you begin introducing or increasing a feed designed for broodmares — and the key word is designed, because what the late-pregnancy mare needs most is not just calories but quality protein (good amino acid profile for that fast-growing foal) and the right minerals. Calcium, phosphorus, copper, and zinc in correct amounts and ratios in the last trimester are directly tied to the foal's skeletal development; copper in particular, fed to the mare in late gestation, is linked to lower rates of developmental orthopedic disease in the foal. A plain oat scoop doesn't deliver any of that. Make the increase gradual, the same way any feed change should be handled, to protect the mare's gut.

Then she foals, and the real demand arrives. Lactation is the single most nutritionally expensive thing a mare does — peak milk production in early lactation can roughly double her energy needs over maintenance and dramatically increase her protein, calcium, and phosphorus requirements. A mare that looked perfectly fed through pregnancy can drop weight fast in the first two months of nursing if you don't step the feed up to meet it. This is the time to feed her generously on a quality mare-and-foal or lactation feed alongside all the good forage she'll eat, and to watch her body condition weekly rather than monthly. A nursing mare losing weight is also a mare whose milk and whose ability to rebreed both suffer.

A few specifics worth getting right. Keep clean, unlimited water in front of her at all times — a heavily lactating mare drinks a remarkable amount, and milk production falls off fast when water does. Make sure she has free-choice salt and an appropriate mineral source. Don't forget that her overall management through gestation, the vaccination and deworming timing and the body-condition monitoring covered in broodmare care through pregnancy, works hand in glove with the feeding program — nutrition isn't a separate silo from her health calendar.

Pay attention to the foal's eating, too, because the back half of lactation overlaps with the foal learning to eat solid feed. Foals are natural copycats and will start nibbling the mare's ration within weeks; many farms set up a creep feeder so the foal can access a foal-appropriate feed the mare can't clean out. By the time you're heading toward weaning, the foal should be getting real nutrition from forage and feed rather than relying on milk, which is exactly what makes weaning with less stress possible — a foal already eating well doesn't hit a nutritional wall when the milk goes away.

The whole thing comes down to feeding the curve instead of the calendar in your head. Quiet on a balancer and good forage for the first two-thirds. A measured, quality-driven increase through the last trimester aimed at the foal's bone and the protein it needs. Then a real, generous step up the day she foals to fuel the milk, watched weekly and adjusted as she tells you. Get the timing right, keep forage at the center, and you'll wean a well-grown foal off a mare that's still in good flesh and ready to do it again.