Lactation is a very important function in a mare. So important, in fact, that two lives depend on it. A mare’s body will sacrifice her foal’s health to save her own life … both during gestation and after foaling. In other words, you must feed her adequately to maintain her body condition with surplus calories to feed the placenta during gestation and to make milk to fill the udder after foaling.

Many nutritionists believe pregnant mares should be fed the same as nonpregnant mares until the last third of gestation, when nutrient intake might increase to 1.3 times the level of the nonpregnant horse.

During the heaviest lactation periods, a mare might require 1.5 to 1.7 times the nonpregnant horse’s nutrient density, and she might need 50-75% more water. Mares that have had foals before might start producing milk in the final 30 days of gestation. Maiden mares might also secrete milk during this time, but many will not produce milk until the hours before foaling. Both situations are considered normal