I have a theory that antler velvet itches when it is about to be shed, which accounts for the start and a portion of the thrashing and rubbing of antlers on trees, branches, posts, and one another. This is not to be misconstrued as the ONLY reason rubs and fighting is initiated.
The velvet is filled with blood vessels and nerves as it becomes the sheath for the newly forming antler. The vessels bring the nutrients that form the growing antlers. If the velvet is damaged, the antler grows irregularly (there are other means for irregular antler growth too).
When the antler approaches maturity, the velvet begins to harden. Blood vessels close and nerves die. There is a cross over between antler hardening and velvet shedding that is initiated when the velvet begins to itch. The antlers are sufficiently hard, and the itch, when it becomes intolerable, is the beginning of the shedding process and signals both chemically and physically the need to start the rubbing process. After that, it is probably just testosterone.
A human analogy to this concept is not unlike deeply sunburned skin. When it is peeling it itches and you want to rip off your dead skin to make the itch go away.
Just testing my theory against your responses.
