Facebook post by University of Helsinki

Contrary to earlier assumptions, the intestines of newborn calves are not sterile but contain DNA from various bacteria. Bacteria or their fragments originating in the dam may be significant to the development of the intestinal immune system.
Signs of bac­teria already in the bovine fetus helsinki.fi

When calving was imminent, the students hurried to the cowshed to collect samples at the moment when the calf came out of the uterus.