BodyBoost Colostrum offers 100% Natural Bovine colostrum. It is the pre-milk liquid produced from the mammary glands of cows. Colostrum from the first milking produced when a calf is born has significantly higher levels of immunoglobulins (Ig), proline-rich-polypeptides (PRPs) and other important bioactive components. We accept colostrum from the first milking only.