Whitetail Deer Hunters! and Big Giant Whitetails. .. Antlers Antlers are live tissue, composed of bone. Antlers are often mistaken as horns. Horns are permanent, where as antlers are tissue which fall off annually. Antlers are the fastest growing tissue in the animal kingdom. Antler size is determined by genetics, age, and nutrition. They grow at an average of 1 to 2 inches per week during development. During growth antlers are covered in velvet, which contains a network of blood vessels and nerve endings. Decreasing day length in the late summer triggers many physical changes in the buck, including termination of the blood supply to the antlers. Antlers start to harden and the velvet dies and starts to peel off. Bucks will use trees and shrubs to rub their antlers on to remove the remaining velvet. With their hard polished antlers, bucks will strive to gain dominance.