Tailor your dam and foal’s feeding program from late pregnancy to weaning with expert guidance.

As your mare approaches the final stages of pregnancy, the countdown to her foal’s arrival can feel like an eternity. But while it might seem like little is happening, the final three months of gestation are critical for both the mare and the unborn foal. Planning the mare and foal diet becomes important.

During this time her nutritional needs intensify, and a carefully planned feeding program becomes essential to ensure both mare and foal thrive.

Here, Kris Hiney, PhD, an extension specialist and associate professor at Oklahoma State University, in Stillwater, and Laurie Lawrence, PhD, a professor in the University of Kentucky’s College of Agriculture, Food and Environment, in Lexington, share their insights on creating an effective feeding strategy to support your mare’s late-stage pregnancy and the foal’s early development.

Feeding Late-Gestation Mares—The Last 90 Days

Hiney explains that until the last 90 days of your mare’s pregnancy, the feeding routine mimics that of a horse in light work. However, during the final three months, her nutritional needs increase to support both her energy requirements and the developing fetus.

“The nice thing is that late-gestation mares are not hard to feed as long as you’re making sure (they are) in good body condition,” Hiney says.

Veterinarians and equine nutritionists consider a score of 5 to 6 on the Henneke body condition scale ideal for these mares. At that level you might not see the ribs but can easily feel them. A horse at a 6 has a little more fat cover, but you shouldn’t have to dig to find a rib on the horse. In colder climates Lawrence prefers mares stay at a 6 in the last three months of gestation to ensure they have enough reserves for lactation.

“Mares that are heavy milkers may benefit from being close to 6 so they don’t become skinny during lactation,” Lawrence says. “Every mare is an individual, but I would recommend that she have free access to good-quality hay, possibly an alfalfa-grass mix (grasses such as timothy or orchard grass), or good-quality pasture, or a combination of both and then enough concentrate to maintain a body condition score between 5 and 6.”

Pasture as Part of the Mare’s Diet

Indeed, grass can be an acceptable forage source so long as it’s good quality. Pasture is not merely something with a fence around it, says Hiney. If you rely on pasture to meet your mare’s nutrient requirements, it must contain grass species—not weeds or forbs (flowering plants with broad leaves and soft stems). For maximum nutrition, grass should be 4 to 6 inches high because grass in the early stages of growth contains higher nutrient levels.

“If the forage is sparse, I might be worried that it’s not going to meet that broodmare’s nutrient needs,” Hiney says. “That doesn’t mean pull her off pasture, but you might need to step in with supplementation.”

Both Lawrence and Hiney stress that when grazing mares on tall fescue or feeding fescue hay, it must be free from the toxic endophyte found in some of these plants. Endophyte-infected fescue can cause health complications in late-term mares such as prolonged gestation, dystocia (difficult birth), and low or no milk production, and it increases the fatality risk in foals.

Formulated feeds also make up part of the ration equation for most horses. Late-gestation mares weighing around 1,200 pounds need 2 to 3 pounds more grain than their nonpregnant counterparts, Hiney explains. But this depends on several factors, including forage quality and the energy density of the feed concentrate.

“If access to pasture is unavailable and/or hay is limited, mares could require a high-quality grass hay at 1% of her body weight in combination with as much as 6 to 7 pounds of a typically formulated grain mix daily,” Hiney says.

Feeding Lactating Mares and Foals to 3 Months Old

The minute the foal touches the ground, your mare’s nutritional needs skyrocket. The foal relies on mom exclusively for his nutritional needs until about 2 months of age.

“People don’t realize how much milk production ups her nutrition needs,” Hiney explains. They “go up to almost twice as much as a maintenance horse. That’s a big jump if you haven’t had broodmares.”

On average, a 1,200-pound mare needs 12 to 15 pounds of an average-energy-density grain mix in addition to 10-12 pounds of a good-quality hay to meet her energy needs at this point, says Hiney. Protein plays a critical role during this time frame, and Hiney says owners commonly supplement mares with a 16% protein concentrate. However, consider the forage source—get the hay tested—before determining how much concentrate to provide.

“If you’re feeding 18% (protein) alfalfa hay, the mare is already getting quite a bit of protein from that source,” Hiney says. “You have to know what’s in the forage and then map it out.”

Lawrence adds that mares can produce 5 gallons of milk or more per day during lactation, most of which consists of water. Therefore, she recommends providing an abundant water supply. It should be the equivalent of at least two 5-gallon buckets of water per day.

The Foal Diet

While milk is the primary nutrient source for foals under 2 months of age, most will start eating their mother’s feed and hay soon after birth. By about 2.5 months of age, the foal’s nutrient needs exceed the nutrients provided by milk alone, so you need to provide enough good-quality forage for him, as well.

“At this time, it is probably a good idea to start introducing the foal to its own feed tub and providing some concentrate (one-half pound or so to start) twice a day,” Lawrence says. “Some babies are really aggressive and run their mothers from the feed tub.”

Hanging feed tubs out of the foal’s reach can keep him out of mom’s ration. Nose bags for the mare are another option. Similarly, mares might need to be kept out of the foal’s portion. Feeders with bars set narrower than the mare’s muzzle and paddock exclusion areas that only the foal can enter can prevent the mare’s consumption. Putting the mare and foal in separate stalls during feeding serves a dual purpose of preparing the two for weaning.

Mares and foals can quickly look unthrifty if the mare does not receive adequate nutrition. Lawrence and Hiney agree it’s essential to observe the mare and foal closely and assess their body condition scores regularly to make necessary feeding adjustments as soon as possible. Fortunately, mares typically eat more forage and supplemental concentrates when provided.

“Keep in mind that when pasture is abundant, some mares will gain weight and may not need a true concentrate feed, but they still need mineral fortification,” Lawrence says. “Offering 1 to 2 pounds of a ration-balancer feed can be the solution to meeting needs without adding extra calories that result in excess weight gain.”

Feeding Foals 3 Months Old to Weaning

By 3 months of age, a foal consumes and uses nutrients from pasture, hay, and concentrate feeds in addition to continuing to nurse. Gradually increasing his ration during the next few months helps reduce the amount of stress experienced at weaning.

“At six months, you want the foal eating what he will be eating when weaned,” Hiney says. “Nutritionally, that is the least stressful for him (compared to) an abrupt change in grain or forage.”

Lawrence shared the advice of one of her mentors: Feed one-half to 1.5 pounds of concentrate per month of age. That would mean the foal receives 2.5 to 7.5 pounds of concentrate by the time he’s weaned at 5 months old. Generally, the foal approaching weaning should consume 3 to 5 pounds of concentrate (formulated for growing horses) with good- to high-quality forage.

“That seems like a huge range, but it would be adjusted on the size of the foal and the quality of the forage,” she says. “If the forage is low in digestibility and nutrients, then more concentrate is needed. Likewise, if the forage is ultra-high quality, then the lower range is used.”

Keep in mind overfeeding can lead to rapid growth, which increases the risk of joint and bone diseases such as osteochondritis dissecans (OCD), a condition commonly diagnosed in young horses. This issue occurs when joint cartilage doesn’t form properly, leading to inflammation and potential lameness. Excessive growth can also simply stress the developing musculoskeletal system.

On the other hand, a young horse that isn’t receiving enough nutrition and is growing too slowly might experience stunted development.

Feeding the Mare At Weaning

As the foal’s ration increases, the mare’s should decrease, says Hiney. For example, if the dam receives 10 pounds daily, backing down to 7 or 8 pounds helps prepare her for the transition as well.

After weaning, don’t forget the mare. First, nursing is the main stimulator of milk production. Once the foal is gone, the mare’s supply will dry up, Lawrence explains. Removing her feed does not make this happen.

“Second, we are pretty sure that mares mobilize some mineral stores during late gestation and lactation to maintain milk production and all of her own important body functions,” she says. “This happens in women who are nursing to some extent, regardless of nutrient intake.”

In women, depleted mineral stores (in the bones) are replaced after lactation ends. This likely happens in mares as well. But in many mares the end of lactation coincides with the fourth or fifth month of gestation if they are rebred.

“Important fetal development is occurring at this time, and the accumulation of fetal mass begins to escalate,” Lawrence says. “The window of opportunity to replenish stores is probably small. Fall pasture is often abundant, and mares maintain weight with minimal concentrate … but fortification is still needed, so (this is) another opportunity to use a balancer pellet. If a mare ends lactation with a body condition score of 5 or less, then concentrate intake is maintained to provide for both replenishing of fat stores and other stores.”

Mare and Foal Diet – A Balancing Act

Mares and foals through late gestation to weaning need sufficient nutrition to support overall good health. Providing the dam enough forage and concentrate feed to maintain a body condition score of 5 to 6 requires a balance of skill and knowledge. But avoiding overfeeding—especially in young horses—holds equal importance to avoid joint disease. A well-designed and managed feeding program promotes steady, moderate growth, helping the young horse reach his potential while taking into account his unique needs