During the first eight months of pregnancy, a mare may be fed like any other horse, with a balanced, high-quality diet. But things are changing rapidly during the final three months of pregnancy. The mare now requires more calories, more protein, more omega 3s, and balanced vitamins and minerals, not only for the unborn foal, but also to prepare for milk production.
Grass hay or pasture should be provided ‘round the clock; she should never run out. If allowed to self-regulate her intake, she will likely consume 2.5-3.5% of her body weight as forage. Alfalfa hay should also be included to balance her protein needs. Alfalfa should never be fed exclusively (due to potential mineral imbalances). Strive for a 60:40 ratio of grass hay to alfalfa hay.
The fetus gains 1 pound per day during these final three gestational months. Hay alone will not meet all the mare’s caloric needs. Furthermore, hay is missing many vitamins that would be found in living, fresh grass, likely not available during these late winter/early spring months in most of the country.
A quality commercially-fortified feed designed for broodmares will meet her nutritional needs as long as it is fed according to recommended amounts. Or you can mix your own feed by offering beet pulp, hay pellets, ground flaxseeds or Chia seeds, and other whole foods, along with a comprehensive supplement that provides balanced levels of vitamins, and minerals such as copper, zinc, and manganese, as well as selenium and iodine.
Attention to nutrition will help the mare maintain strength and health in this final stage of pregnancy as well as be ready for the significant demands of milk production and nursing.
Juliet M. Getty, Ph.D. is an internationally respected, independent equine nutritionist who believes that optimizing horse health comes from understanding how the horse’s physiology and instincts determine the correct feeding and nutrition practices. She is the Contributing Nutrition Editor for the Horse Journal, and is available for private consultations and speaking engagements. Her books include the reference resource, Feed Your Horse Like a Horse, plus the seven current volumes of the Spotlight on Equine Nutrition series on specific topics of interest to horse owners. Getty provides a world of useful information for the horseperson at www.gettyequinenutrition.com. Sign up for her informative, free monthly newsletter, Forage for Thought; browse her library of reference articles; search her nutrition forum; and purchase recordings of her educational teleseminars. Her books are all available through her website with special pricing offers. And for the growing community of horse owners and managers who allow their horses free choice forage feeding, Getty has set up a special forum as a place for support, celebrations, congratulations, and idea sharing. Share your experiences at jmgetty.blogspot.com. Reach Getty directly at email@example.com.