If they're anything like cats' whiskers, they don't have nerves in them.
Also, if they're anything like cats' whiskers, they're used mostly forgiving the bun an indication of their body size (as in when they try togo into a hole, to know if the hole is big enough for their body), andI assume they're also to help them feel things happening around them(like if something is close-by and they can't see it, they'll feel itwith their whiskers).
So, while I don't think it would hurt the bun physically to cutthem, I think it would hurt instead by way of the bun no longer havingthose indicators.
That's, of course, if they're like a cat's whiskers. Hehe.
I wouldn't think they had nerves in them butthey have a lot of nerves at the base. I've seen rabbits chew eachotherwhiskers and neither cried out in pain, however tugging on them wouldbe painful I would imagine.