05/05/2026
Feeding the Pregnant Mare
Brian S. Burks, DVM
Diplomate of the American Board of Veterinary Practitioners®
394 Fox Road
Apollo, PA 15613
(724) 727-3481
www.foxrunequine.com
Up to 60% of fetal growth occurs during the last half of gestation. The fetus grows slowly during the first half of gestation, about 0.2 pounds per day.
During early gestation, the broodmare can be fed a maintenance diet, being fed like a mature, idle horse. Good-quality hay or pasture, along with a vitamin/mineral supplement is sufficient.
During the last half of gestation, nutrition requirements increase dramatically. The fetus grows at about one pound per day, significantly impacting requirements for protein, vitamins, and minerals. Forage intake may decrease as there is less room in the abdominal cavity, so it is important for mares to be at a body condition score of six, on a nine-point scale when they foal so that there are sufficient energy reserves for early lactation, and to maintain condition for re-breeding. Mares should be given a balanced feed ration to meet nutritional requirements. Good quality forage might maintain body condition, but protein, vitamins, and minerals will be deficient.
Here are some general guidelines to keep in mind:
• Good quality pasture or forage might provide sufficient energy through late gestation, but might not provide adequate amino acids and minerals.
• A ration balancer product or a feed designed for pregnant mares can be used from month five to about month 10 or 11 of gestation to provide the missing nutrients.
• A feed designed for broodmares and foals should be introduced prior to foaling, so that the mare is properly adjusted to the feed well before she foals. She is under quite a bit of stress immediately before foaling, so this is not the time to be introducing a new feed. This feed can then be increased after foaling to provide both the increased energy and the increased nutrients that are required for lactation, as well as providing nutrition for the foal when it starts to nibble on feed.
• Fresh clean water and free choice salt should always be available.
• The mare should also be vaccinated properly before foaling so that her colostrum, the rich first milk, contains antibodies to protect the foal. Proper nutrition will also help immune response to vaccinations.
If adequate protein is not provided, foals may be small and weak. This can occur even when the mare appears in good flesh, as there are sufficient calories, but good quality protein is lacking. This can even be true for mares being fed alfalfa as important amino acids may be lacking.
Minerals become needed for foal growth and bone formation during the last few months of gestation. Trace minerals should be provided as they are critical for fetal development. Mineral retention is important during the first weeks of life, but they may be lacking in the diet. Proper mineral nutrition of the mare during late gestation provides minerals for the foal to use during early growth. Some areas are low in selenium and others may be low in iodine. Some supplements may contain too much iodine. Check with your veterinarian regarding any supplement.
During lactation, energy requirements are doubled over maintenance. Water consumption increases nearly 100% while producing milk for her foal. By 24 weeks post-partum, milk production begins to decrease, and the caloric content of the diet can be decreased toward maintenance.
Proper nutritional management of the broodmare during late gestation will give the foal the best start in life. With the time and money invested in getting a foal on the ground, it is important to provide adequate mare nutrition during this critical time.
Fox Run Equine Center
www.foxrunequine.com
(724) 727-3481
