Diet for best flavor?

I have a friend who is about to help me set up a small personal rabbit farm. He feeds them what grows naturally in his woods. I do other farm work as well, and in the process of butchering some lamb, I’m told it’s a good thing we let the lambs graze for the sake of meat flavor, just as beef develops a better flavor on grain as opposed to grazing. So, Here’s my question: does any one here have experience on flavor notes and particular diets? What kind of diet would favor the best flavor possible in rabbit meat?