Happens often, even around the rut on green fields you see alot of this with matron does kicking at young bucks. funny, but when i start seeing that happen i know the rut is one step nearer than a few days before!!! bucks will too if no antlers avail. had a friend witness this in early turkey season when a young doe came in heat and ran down in front of him and they had no antlers and fought like this..........wish he had a camera!!!