Quote Originally Posted by Elmetiacos View Post
It's actually only assumptions about the word, but based on the fact that it would extremely weird for people to borrow someone else's word for something as familiar as a pig.
This is not inconceivable. For instance the English word bag was taken into the language from Norse. This is also a very familiar thing.

You can see the etymology on http://en.wiktionary.org/wiki/bag.