If it was high fence it doesn't matter how many u kill is that not right? They are not free range animals so the one buck doesn't apply to high fence right?
Depends on the state laws and/or regulations. But just saying "it's in a pen, I can do whatever I want" usually isn't going to happen.
As Fred said, kill a buck illegally and transport it across state lines - federal screwup and no Monopoly cards can help you get out of jail.