At first glance and even when snapping the photo I thought a hawk had taken a meal of rabbit while on the fence. The tuft of hair/fur is caught on one of the 'barbs' and I thought it was somewhat peculiar that individual hairs were just stuck straight out on the wire. There was another tuft on the ground. Maybe the hawk was flying over the fence and the rabbit snagged on the barbed wire. But, after uploading and looking at the photo again I am thinking maybe it was from a deer that jumped over the fence and gave up some hair from it's belly. I guess it's a question without an answer.