No, they're not "kept in cages". You may be thinking of the stanchions they're put into for milking, but they're only put in those during the actual milking pr

No, they're not "kept in cages". You may be thinking of the stanchions they're put into for milking, but they're only put in those during the actual milking process, which only takes a few minutes with modern milking machinery. Usually they're fed something tasty while being milked... makes it easier to get them to go into the dairy barn.