He may have been pulling your leg. We bottle feed the calves formula, because to allow the calves to drink the milk would defeat the purpose of raising dairy cows. Also teat cleanliness and health is huge; suckling causes problems.
Incidentally, wild cows actually are a thing in a bunch of far-flung places. I saw them in the Aleutian islands (some genius brought them up there thinking he could get a beef business going and just left them when it of course failed) and they're mean as hell. There's a bunch of feral cattle on the Big Island of Hawaii as well, and TIL there are ~5 million stray cows in India where it illegal to kill them for religious reasons, which creates a massive problem for transport infrastructure, and gave rise to possibly my all-time favorite wikipedia article title: