In fields and barns/byres.
Cows are domesticated animals and have been selectively bred through hundreds and thousands of generations to give us what we have today in our farms. Their original ancestors may not have been like the livestock that we have today which provides us with meat and milk. They are kept in places which are either close to meadows that offer abundance of food for them or in case of corporate farms they are kept in specialized farms that are equipped with facilities to monitor them and keep them in healthy conditions in order to ensure that they produce quality meat and other dairy products.
Cow shed
Shed
Up your butt idiot