There are about as many ways of feeding colostrum as there are farms. I have seen colostrum fed as fresh, chilled, pooled, frozen and even colostrum replacer. The undisputed best is fresh and here's why.
Fresh colostrum, because it doesn't have to be stored for any length of time, doesn't overgrow with bacteria. Bacterial overgrowth in colostrum can be a death sentence for a calf. The same mechanism that allows for antibodies to be absorbed intact into the bloodstream from the calf's gut also allows bacteria to be absorbed. Bacteria in the bloodstream of a baby calf is bad news.
Even if colostrum is chilled or frozen, it doesn't mean that the bacteria don't have time to multiply. The capacity of the refrigerator or freezer to quickly chill and the volume that is to be chilled or frozen can allow much of the colostrum to remain warm for hours. That's plenty of time for the logarithmic growth of bacteria to occur.
Under warm conditions, bacteria can double in population roughly every 20-30 minutes. This means that in 8 hours, good quality colostrum can have a bacterial population that exceeds 2 million bacteria per milliliter. That's more than enough challenge to kill a calf.
Fresh colostrum also contains white blood cells from the mother that impart "memory" to the calf's "uneducated" immune system. These white blood cells act somewhat like a vaccine to prime the calf's immune system to respond to a pathogen quicker than it would be able to without them. This effect is lost when colostrum is stored or when a replacer is fed.
I have just a couple of things to say about colostrum replacers. First, if you have a colostrum replacer product, make sure it is indeed a replacer and not a supplement. Replacers must contain at least 120 grams of immunoglobulins, or antibodies, to have a minimum of effectiveness.
If they contain less, they are only supplements and won't impart adequate protection to the calf. Second, they shouldn't be used routinely but only as a last resort when fresh colostrum is unavailable. Even colostrum replacers, while convenient and biosecure, do not give adequate protection to fully one-half of the calves that receive it.
In addition to its laxative effect and immune stimulating properties, colostrum is also loaded with energy and vitamins that can give that calf a great start in life. This brings me to the second major thing that can get a calf through the winter- adequate nutrition to stay warm. That will be the topic for next month.