Colostrum: Your Calf's Health Depends on It!

In a separate article, colostrum was mentioned as an important part of preventing navel infections, but its impact has a much broader reach. It is really the key factor in preventing ANY infection in calves. Though we typically think of colostrum as supplying critical antibodies (or immunoglobulins) to fight off pathogens, it does much more. In addition to antibodies, colostrum has higher concentrations of many nutrients when compared to milk, it provides growth factors important to the developing calf, and fresh colostrum can even transfer immune cells to calves, further bolstering the calf's immune system. Ideal colostrum management assures a calf gets plenty of clean, high-quality colostrum soon after birth. Pairing these practices with routine monitoring provides calves with the best start possible.

To make sure calves get the immunoglobulins and other factors delivered by colostrum, it is important to ensure they are getting enough colostrum. The general recommendation for first colostrum feeding is to feed 10% of body weight—that means about 4 quarts for a Holstein calf and 3 quarts for a Jersey. This may seem like a lot, and the calf may not be hungry for a while afterward, but this provides plenty of antibodies and a big dose of energy for the calf.

In addition to measuring the volume of colostrum we feed to calves, we can also measure the relative concentration of antibodies in the colostrum, assessing its quality. Though many people claim they can tell how good colostrum is by looking at it, this has been proven false many times. The two best ways to measure colostrum quality are by using a colostrometer or a brix refractometer. A colostrometer provides a simple way to assess quality, with most providing a red/yellow/green color scale. A brix refractometer gives a brix reading in percent, with colostrum over 22% being considered good quality. For more information on colostrum quality, check the Penn State Extension website.

Colostrum quality is closely tied to the timing of colostrum harvest. Around the time of calving, the cow stops making colostrum and begins making regular milk. As this happens, any colostrum present in the udder begins to be diluted with regular milk. The sooner after calving that we can milk the cow, the better quality the colostrum will be. Another way to think about colostrum quality is in terms of the cleanliness of colostrum. Milking a cow for colostrum should be done just as cleanly, or even more so, than when milking in the parlor.

It is also important to store colostrum properly if it is not going to be used right away. Prompt refrigeration or freezing prevents any bacteria that may have gotten in the colostrum during the collection process from rapidly growing. Minimizing bacteria in colostrum through proper milking procedures and storage not only reduces the likelihood a calf will be exposed to potential pathogens during the first few hours of life, but also improves absorption of antibodies. When bacteria are present in the colostrum, some of the antibodies will bind to these bacteria, making them unavailable to the calf for absorption, so clean colostrum will provide better long-term benefits to the calf.

As much as timing of colostrum harvest is important, so is timing of feeding. Calves gradually lose the ability to absorb antibodies from colostrum, so the sooner they are fed colostrum, the better. Ideally, calves will receive colostrum within the first 2 hours after birth, but sometimes this is not possible, especially on smaller dairies where overnight care is not available. In this case, it is important to have a plan for getting colostrum into calves found first thing in the morning. One way to manage this is to have frozen colostrum available, allowing calves to be quickly fed colostrum even before morning milking. Although the ability to absorb antibodies dwindles as the hours pass after birth, more and more research has shown the benefit of additional colostrum feedings.

The high level of nutrients, growth factors, and other unique aspects of colostrum provide benefits beyond the first feeding. If your operation has excess colostrum, consider feeding it to the youngest calves to give them an extra boost. Just as we monitor milk quality, we should also monitor how well a colostrum program is working. Drawing blood and testing for total protein in young calves provides a good measure of how successful a colostrum program is. Talk with your veterinarian about how to incorporate colostrum program monitoring into your herd health program to make sure your calves get the best start possible.