Six Steps to Feeding a Pregnant Mare

Choosing to breed a mare involves a multitude of decisions, some that require protracted thought (“What stallion should I choose?â€) and others that can be made almost instantly (“Who will foal out the mare? Me, of course!â€). Providing adequate nutrition for the mare as she transitions from one trimester to the next need not be difficult. Use the following six guidelines to stay on track, helping to ensure the delivery of a healthy, nutritionally robust foal.

1. Familiarize yourself with body condition scoring. If you’re not proficient at body scoring yet, having a pregnant mare in your care is an opportune time to start. As pregnancy advances, the mare will inevitably gain weight, mostly in her abdomen. Key points of fat deposition, however, should remain similar throughout the duration of her gestation. A pregnant mare should be kept in moderate to moderately fleshy body condition throughout pregnancy.

Body condition above a score of 6 only adds unnecessary weight to the mare’s limbs, and this could be difficult for a mare that has soundness issues, including arthritic changes from past performance careers. One exception to this point: if a mare is known to drop weight exceedingly fast at the onset of lactation, she might be kept at a slightly higher body condition score to help cope with the energy drain of milk production.

2. Provide vitamins and minerals. For the first seven or eight months of pregnancy, the mare requires no special upgrade in calories. She does, however, need sufficient intake of high-quality feedstuffs to maintain moderate body condition. The primary feedstuff should be good-quality forage in the form of pasture or hay, and a source of essential vitamins and minerals. These nutrients can come from a well-fortified textured or pelleted feed formulated especially for pregnant mares, or from a balancer pellet, which is a concentrated source of protein, vitamins, and minerals. If the mare needs the calories from feed to maintain her weight, be sure she consumes the recommended amount as provided by the feeding instructions. This way, her vitamin and mineral needs will be satisfied, as will those of her developing fetus.

3. Resist the temptation to overfeed. A common management mistake among well-meaning mare owners is overfeeding during the first seven to eight months of pregnancy. The fetus does not grow at an even rate during pregnancy; in fact, most fetal growth occurs in the final three months of gestation. Because of this, energy needs of the pregnant mare do not increase greatly until then. Keeping the mare in moderate to moderately fleshy body condition and supplying appropriate vitamin and mineral nutrition are the most important management tips during early pregnancy and midpregnancy. Mares should never be obese, as this can make delivery more difficult.

4. Reconsider energy levels in late pregnancy. During the last three to fourth months of pregnancy, the mare’s requirement for energy increases as the fetus grows. Providing the mare with high-quality forage on a free-choice basis can add calories to the diet. The mare should continue to be fed a feed designed for pregnant mares or a balancer pellet at the manufacturer’s recommended amount.

Gauge the diet through regular, preferably weekly, body condition scoring. As the weight of the fetus and associated fluids increases, the abdomen drops, and gravity will sometimes cause the flesh to pull tightly against the ribs of the mare, allowing a hint of rib to show. This is normal, especially among aged mares with relaxed toplines that have had many foals, so it is essential that all regions of the body are inspected for fat deposition, such as the crest of the neck, along the shoulder bed, over the croup, and near the top of the tail.

In addition to high-quality hay and well-fortified feeds, mares can be given extra calories through the provision of stabilized rice bran or vegetable oil (ideally soybean or canola oil).

5. Salt, water, and fescue. As with all horses, provide a pregnant mare with free-choice access to a fresh, clean water source and a salt block or loose salt. One type of hay or pasture to avoid is fescue, which is often infected with an endophyte that causes problems in pregnant mares, including prolonged gestation, difficult delivery, and lack of milk. Make sure all bedding is free of fescue, too.

6. Rely on an equine nutritionist. The fundamentals of feeding a pregnant mare are straightforward, though occasionally a scenario pops up that requires the help of a professional. When in doubt, recruit a nutritionist for assistance. Kentucky Equine Research (KER) offers a free nutrition service to mare owners. Contact a KER nutrition advisor today.