It must seem as if every time veterinarians talk about the health of new-born calves, they end up talking about how important colostrum is. That is likely true because they do believe that good colostrum management is essential.
There aren’t too many other things you can do for a calf that is more beneficial than making sure it gets a belly full of good colostrum not long after it’s born. Veterinarians keep talking about it because study after study have shown that there are still lots of dairy calves where that doesn’t happen. So many calves don’t appear to get enough good-quality colostrum soon enough. That likely means that colostrum management is more difficult than it sounds.
So, colostrum management might sound easy but it is maybe not so easy to do.
In trying to work out how to make it easier, veterinarians tried to figure out if there were easy ways to identify poor-quality colostrum. If you found that the cow’s colostrum wasn’t good quality, you can feed better quality — either frozen colostrum from your own farm or feed commercial colostrum.
The easiest way to test the quality of colostrum is to use a BRIX refractometer. It doesn’t measure the amount of antibody in colostrum, it measures the total solids which is an estimate of the antibody. Because it is an estimate, the BRIX isn’t 100 % accurate but it is easy to use and is much better than any other method you can use on farms. You just need to accept that BRIX is not 100 % accurate and work around its limitations by only accepting the best-quality colostrum to feed calves.
As more investigations were done into why it is so difficult to make sure every calf gets the benefit of colostrum, it became obvious that bacteria contamination of colostrum impacted its value.
If colostrum has a lot of bacteria in it, the calf doesn’t absorb the antibody in the colostrum very well.
Colostrum can get contaminated when the cow is milked out. That is why veterinarians recommend that you prep the cow as if you were milking her into the tank. Colostrum can also get contaminated if the milker or the colostrum containers aren’t clean.
Bacteria can multiply very quickly in colostrum even when it is relatively clean when collected, so colostrum should be cooled. It should be refrigerated if you don’t feed it right away or if you plan to keep it for other calves.
A recent research trial looked at testing for contamination of colostrum using the same on-farm cultures that some farms use for clinical mastitis. It turns out that you can get a good idea about how many bacteria are in the colostrum. This might not be something you would do all the time but it would be useful to spot check colostrum or if you started to see calf health problems.
Because there are so many steps in good colostrum management, it is wise to routinely test calves to check that you are doing a good job. You can use the BRIX to test blood from several calves. As more research adds to our knowledge on the link between good colostrum management and good calf health, the guidelines for BRIX readings of calves have changed. I wrote about the newest guidelines last June.
There is a downside if you only test calves to evaluate colostrum management. The downside is that by the time you do the test, you can’t really do much to help calves that didn’t get enough protection. It does tell you that you likely need to do better going forward.
Dr. Robert Tremblay is a veterinarian for Boehringer-Ingelheim and lives near Guelph.
