Cows stuck, not being milked

AI of cows currently does not work if they are completely enclosed by a fence/wall. This can be solved by simply leaving a hole in the fence around the barns.

Upgrading the cowshed to level 2 can also occasionally disable the herd, so it's best to stick with level 1 for now.

Fully fencing off cows can drastically reduce productivity as their frantic AI searches for solutions.