Importance of Colostrum

Although some are finishing up calving and others are still yet to begin, it is always necessary to remember the importance of colostrum. This is the first milk produced by a cow after she has given birth. Colostrum contains immunoglobulins, IgG in particular, as well as white blood cells, milk fat, and vitamins A and E. All of these components are important to the newborn calf. A calf is born without immunoglobulins, because the placenta prevents immunoglobulins from being transferred from the cow to the calf in utero. Immunoglobulins are proteins that act as antibodies to protect the immune system from disease and help to establish the calf’s immune system. White blood cells help to further protect the calf from pathogens, while Vitamins A and E also play a role in stimulating the immune system and offering antioxidant properties.

Timing is important in colostrum consumption. The calves’ small intestine lining is primed for IgG at birth but that timing window begins to close significantly after 12 hours of life. The peak absorption occurs in the first four hours post-partum, and after 24 hours the gut has completely closed. Difficulty at birth can negatively impact gut absorption of colostrum, as can cause metabolic acidosis. Because of this, it is advised to ensure adequate colostrum intake of calves with births you assisted in.

A very important point to note is that not all sources of colostrum are created equally. The best source of colostrum, of course is that of the newborn calf’s mother. If that option is not available, the next best option is colostrum from a donor cow from the same operation. When choosing a donor cow, healthy cows with an adequate vaccine history are ideal. Colostrum can be collected, stored in a quart freezer bag, and frozen for up to one year. When thawing the colostrum, remember that the microwave can denature the IgG antibodies, and the best practice is to water bath the colostrum in temperatures lower than 140 degrees F. If providing a bagged colostrum supplement, be sure to read the label. Some are intended for calves that have already received some colostrum, and they do not have adequate IgG levels for newborn calves. It is also important to read the label and ensure that the product you are choosing contains dried colostrum.