Hello lovetodance, and welcome to the board. I did a little googling and this is what I came up with:
Antlers are a tissue that develops under the "velvet", a soft skin-like protective covering. Since they are one of the fastest growing things on the planet, right up there with the science projects in my refrigerator and the elephant grass in my yard, they need a covering that is elastic. Nowhere did I read that it was gelatinous. When the deer enter the pre-rut season, rising testosterone levels harden the tissue and the velvet is no longer required to feed and protect the antlers and so it dries up and is sloughed off. This is an irritant (think itchy scabs) that prompts the deer to rub their antlers against trees and such to rid themselves of the irritant and also is part of the process of marking their territory for mating purposes. The terms I ran across for this are "rub" and "scrape". If you were looking for words that sound a little more edumacated, consider these two:
From thefreedictionary.com
Noun 1. detrition - erosion by friction
2. detrition - the wearing down of rock particles by friction due to water or wind or ice
3. detrition - effort expended in rubbing one object against another
or
Noun 1. decortication - removal of the outer covering of an organ or part
