Although the cows in the last post were pictured walking in from their grassy field to be milked, they were not going out again to sleep in the field. That can only happen in summer when the night time temperatures are warmer than freezing. Until such time they will stay in the barn overnight. Their calves stay permanently inside the barn. Bull calves get fed for about 20 months before going to the place that cattle go to when they are nice and meaty. The heifer calves will probably go on to be milking cows.
The food was meant to be for the cows, but Hugh thought it looked good enough to play with (and it did smell quite tasty...).