Antlers are grown new each year and shed each year after the rut, and are made of bone and therefore are a living tissue. They are not horns [like sheep or cattle] which are made of keratin, which is a dead tissue. Horns keep growing each year and are permanent [like a cow’s hoof].
They are the fastest growing bone know to science and can grow up to one half inch a day.
Antler development is triggered by the pineal gland which responds to the lengthening of sunlight hours in springtime. The amount of light entering through the buck’s eye causes the pineal gland in the buck’s brain to release hormones. These hormones cause the release of testosterone [the male sex hormone] which is the hormone most responsible for antler growth.
Antler development is slow to start, but with the shortening hours of light towards the end of summer, the growth rate speeds up.
The growth begins from the two pedicles on top of the buck’s head and have a modified skin and fur cover the newly growing antlers.
This soft velvety material [called velvet] is rich with blood and nerve tissues and is almost totally made of of a protein called collagen.
Prior to the growth starting, the bucks deposit calcium and phosphorus into their skeletons. During the growth phase, calcium and phosphorus are taken from the buck’s skeleton to help build the antlers, with the balance coming from their diet [while the antlers are still growing].
For bucks to achieve optimum antler development, they need access to calcium and phosphorus, however all of the other trace minerals are only needed in ‘trace’ amounts, and in fact can be toxic in large quantities.
Malformed antlers are usually the result of damage during the velvet stage when the antlers are vulnerable.
Testosterone peaks just before the rut and the buck’s antlers have now hardened under the velvet. As the velvet dries, it falls off or is assisted by the buck rubbing it off on brush and trees.
As the amount of sunlight reduces further due to the onset of winter, the production of testosterone drops and the buck’s behavior changes and he becomes less aggressive.
Antlers are cast in January through March due to a weakening of the joint between the pedicle and the antler. They usually fall off in close proximity of each other and at approximately the same time for each buck every year [see information on antler sheds].
The whole process will start over again in a few weeks when the increasing daylight hours triggers the antler development cycle – the only regenerating living tissue in the animal world!