The first weeks of life are a critical period in the development of the newborn ruminant. Newborn ruminants are quite vulnerable since both on a farm as well as in nature they are exposed to various pathogens. Because they have a placental type that does not allow the transfer of large molecules from mother to fetus during pregnancy, ruminants are born without maternal antibodies. For their first immune defense, they depend almost entirely on the transfer of immune components through the first colostrum. Colostrum contains more nutrients than "regular" milk, and it especially contains more immunological components, such as immune cells and antibodies, also known as immunoglobulins. The first colostrum is one of the most important aspects for a healthy start of young ruminants. The general aim of this dissertation was to improve the knowledge about colostrum feeding strategies and immunological properties of colostrum, in order to better provide young ruminants with a proper neonatal immune system. Various aspects of colostrum are investigated, such handling of colostrum may influence the immunological and bacterial quality of the colostrum, how Dutch dairy farms implement colostrum management and whether the immune cells transferred with maternal colostrum are functional in the young animal.