I don't know about hams, but with puppies and kittens (and foals) there is a window in their development when they first start venturing out of their nest when they are programmed to not be fearful of new things and that is the critical time they need to be socialised to humans. After a couple of weeks the fear kicks back in and you then have a much more difficult time to gain trust.
Love His Lordship in the strawberry xx
