Hi Prof. I found out the hard way why they keep the small calves away from the mothers. After a big smack against my head of course. On my grandfather's farm I let a small calf out to go to his mother and it was happily drinking on its mother. My grandfather arrived with his big smack and he chased the calf back into the enclosure. They keep the calves away from the cows, because they drink the milk and then the cow has no milk when they want to milk it. So there you go. Now you know.
!LOL