What "stimulates" re-growth of antlers is the increasing hours of daylight in the spring, which stimulates the pineal gland in the brain, which regulates hormone levels. This causes increased blood flow to the antler pedicel and the growth/deposit of new bone in the antler.
What "determines" how large antlers grow is age, nutrition (food and minerals), the health of the animal, genetics, and water. If there isn't enough water for good forage growth, then there is poor forage and poor antler production. If the animal is undernourished, injured or sick during the time it is growing antlers, it will have poor antler growth.
Whitetails generally aren't full grown until they are over 4 years old; elk aren't full grown until they are about 7 years old. Until they are full grown most of the nutrients needed for antler growth go into bone and muscle production. Once the animal is full grown it can start growing antlers, which often leads to longer tines and more mass that you see in older deer and elk.
If you have more questions on deer, elk, turkey, ducks or geese ask me and I will try to answer.
T.R. Michels, writer, speaker
Trinity Mountain Outdoors
[email protected]
T.R. Michels
Edited by - trmichels on 10/18/2002 12:32:08