But if you are milking you don't have bulls. Maybe you have one (though almost everyone uses artificial insemination these days). Worrying about milking bulls is like worrying about the NetWare server - once common but has been obsolete since before many reading this were even born.
Of course the pigs, cows, and chickens are not interchangeable. Nor are corn, hay, soybeans.
Of course the pigs, cows, and chickens are not interchangeable. Nor are corn, hay, soybeans.