I got an excellent book for Xmas from Erin's boyfriend, Mike. It is full of information about animals. One interesting fact that I have learned is that most domestic cows are made to ingest a magnet. This then sits in their first stomach for their entire lives and attracts any piece of metal that they accidently eat thus preventing hardware disease. Sounds all rather unlikely eh? But if you google cow magnet the first thing that comes up is a company that manufactures them.
Mind you the entry for donkeys claims that female donkeys can be called a jenny or a donkeyess - haven't found any back up for the latter on the internet!