Mare and Foal Nutrition

Livestock Update, February 2007

Dr. Shea Porr, Northern District Equine Extension Agent, cporr@vt.edu or 540-687-3521 ext 27

This time of year can be hectic, what with mares coming into season, foaling, and breeding, and all of this on top of the average daily grind!  Keeping a few feeding and nutrition tips in mind will help smooth out the breeding and foaling season and help insure healthier, happier horses.

Open mares that you’re intending to breed this season should be in good flesh (body condition score 5) and perhaps even gaining a little weight.  This will help regulate their reproductive cycle and improve the chances of getting them pregnant with fewer trips to the breeding shed.  Be careful not to have the mares too heavy, though, as research has shown obese mares have altered hormone levels that may affect their fertility and conception rates.

In the past, it was thought that early gestation mares could be fed like open mares.  Research is showing that this isn’t true, and that proper nutrition, particularly vitamins, minerals, and protein, early in pregnancy is vital to the developing fetus.  Dietary deficiencies during this time may result in weaker foals or foals more prone to diseases and developmental problems.  Pay a little more attention to the nutrition of the early pregnant mares; they’re not just maintenance animals.

Late gestation mares should be a little on the heavy side (body condition score 6 or 7) to prepare them for the rigors of lactation.  Their nutrition should be increased in the last few months of gestation as the demand for all nutrients rises in the final stages of pregnancy.  Some of these mares may require more concentrate in their diet, as their intestinal tract may be compromised by the size of a large foal, preventing them from eating enough hay or pasture to meet their needs.  Pay attention to the mare’s body condition and make adjustments accordingly.

Lactation places the greatest nutritional demand on any horse and in some cases can almost double the mare’s energy requirements.  If her nutrition isn’t sound, she will pull from the reserves of her body to provide for the foal, losing body condition.  The main goal during this time should be to maintain her body condition while feeding her a well-balanced diet.  If she needs to lose weight, take care of the excess after weaning to prevent any nutrition deficiencies in the growing foal.

Lactation peaks at about 2 months.  By 4 months, the mare is only providing about 50% of the foals’ nutritional requirements.  By 6 months, that has dropped to 30% as production quantity and quality decrease.  These decreases, in addition to natural curiosity, encourage the foal to begin eating solid food, including pasture, hay, and grain, to meet his nutritional requirements.  If the foal can share the mare’s feed, then creep feeding may not be necessary.  However, if there is a reason the foal is prevented from consuming her feed, then setting up a creep feeding system is important.  A well-balanced feed designed for growing horses makes a good creep feed, particularly if it’s the one you’re going to use for the weanlings.  This will get him used to what he’ll be eating in the future and reduce the incidence of problems that might arise from switching to a new feed during the stress of weaning.  Finally, foals should never be allowed to gain too much weight, as this makes them more prone to developmental problems.  Maintaining them at a body condition score of 4-5 is usually optimal.

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