Colostrum is the first milk produced by the mare. The colostrum contains important antibodies and acts as a laxative for the foal. It is critical that the foal ingests these antibodies because it is born with no natural protection from diseases. The antibodies can be absorbed by the foal's intestinal tract for up to 36 hours after birth, but absorptive ability begins decreasing drastically at 12 hours after birth.

For more information, see Care of the Newborn Foal.