Deer and elk antlers are real bones, and the velvet covering the growing antlers is a modified extension of the head’s normal skin. The antlers are the most rapid growing postnatal bone known. When the antlers are shed, a small piece of the outer part of the peduncle is lost. This shortens the outer length of the stalk more than the inner length, causing the antlers to have an ever-increasing expansion each year.
Antler growth begins when the concentration of testosterone in the blood increases, just as a severely reduced testosterone level causes the antlers to be shed. The length of daylight affects changes in testosterone levels. Elk antlers on adult bulls begin to grow as soon as they fall in February or March.
Deer antlers are shed earlier and scab for a few months before new growth begins. Adult male elk antlers weigh between 40 and 50 pounds, but deer antlers typically weigh less than 10 pounds each.