“At birth, the ‘fingers’ of the calf’s intestinal wall are open. This means that the immunoglobulins, the antibodies from colostrum, pass through the intestinal wall into the blood,” Nicolien explains. The intestinal wall can be seen in this image. The blue dots are the antibodies from colostrum, which pass directly through the intestinal wall into the blood.
Intestinal wall immediately after birth.
After six hours, absorption capacity decreased by 50%
A few hours after the calf is born, the intestinal wall already begins to close. “That is why it is so important to immediately give the calf four liters of colostrum with a minimum brix value of 23%. Within six hours after birth, the absorption capacity has already decreased by 50%. After 24 hours, the intestinal wall is closed and the calf can no longer directly absorb the necessary immunoglobulins from colostrum into the blood through the intestinal wall,” says Nicolien. This can be seen in the image below:
Intestinal wall 24 hours after birth.
Feeding colostrum to an older calf
After 24 hours, a calf can no longer directly absorb the antibodies from colostrum. It is useful to also feed colostrum on the second day, because of the other positive substances that colostrum contains.Read more about it here. Do you have an older calf that is at risk of getting diarrhea? Then a few days of 200 cc of colostrum through the milk powder at intestinal level can provide protection, even if the animal cannot absorb the antibodies into the blood.
Also read the other reasons to feed your calf four liters of colostrum within two hours of birth here.