Colostrum and its protective antibodies are present in the mare's milk for only the first day after foaling; these maternal antibodies are necessary to protect the foal against infectious diseases. | Photo: Anne M. Eberhardt/The Horse

Q.How can I collect colostrum from a mare and save it for future use, and how long can I keep it?

—Ashley, via e-mail

A.Colostrum or “first milk” is the thick, yellow secretion from the mammary gland that’s present immediately after birth. Produced in the mare’s udder during the last two to four weeks of gestation in response to hormonal changes, colostrum contains concentrated immunoglobulins (antibodies) from the mare’s serum. Colostrum and its protective antibodies are present in the mare’s milk for only the first day after foaling; these maternal antibodies are necessary to protect the foal against infectious diseases. The best-quality colostrum is produced in the first eight hours post-foaling. Ideally, the foal will receive at least two pints of mare’s milk within the first 12 hours of its life