Understanding Deer Antler Growth
Whitetail antlers are an amazing example of nature’s wonderful and beautiful handiwork! In fact, deer antlers are among the fastest growing tissues in the animal kingdom, growing as much as 1/2-inch per day during peak antler growth. Of course, the amount of antler growth depends upon nutrition, genetics, and age.
Until a buck’s bones are completely developed, body development will always take precedence over antler development. Now you can appreciate why bucks produce bigger antlers as they age and the largest-antlered bucks tend to be the biggest-bodied.
The two circular areas that grow antlers from a buck's skull are known as pedicles. Antler pedicles start developing on the frontal bones of male whitetail deer fawns during late fetal development. After birth, early stimulation from testosterone is then required for final pedicle development. When bucks reach 4-6 months of age, the antlers begin to grow from the pedicle.
Deer Antler growth usually begins during the early Spring in response to changes in growth hormones from the pituitary gland which stimulates antler growth. During this time, the soft growing antler is covered with hairy skin, called "velvet". When antlers are in the velvet stage they are full of blood vessels, cartilage and nervous tissue.
By early Fall, rising testosterone levels and testicular volume, harden antlers through calcification. In this process, soft tissue is converted directly to bone by the deposit of minerals within the cartilage and blood vessels in the developing antlers. it is now that the velvet will begin to dry and falls off. The buck will help it along by rubbing his antlers on trees, shrubs and saplings.
Definition of Antlers
They range from tiny sharp spikes to amazing typical and non-typical racks. Antlers develop into every size and shape. But, a great deal of misinformation has been passed down over the ages. One major mistake is commonly made by hunters who don’t know that antlers are not horns, and horns are not antlers.
Antlers are made of dead bone, and are yearly growths that begin growing from two pedicels on the buck’s head in late winter and early spring. Antlers reach full growth in late summer usually October. Antlers are normally branched (except for spikes), and maturity, good nutrition, lack of stress and good genes determine antler size and formation.
As a rule, only male deer grow antlers. But one female (doe) in several thousand whitetail does will grow antlers because of a hormone imbalance.
Horns, rather than antlers, are living bone that is covered with hard layers of skin. They are typically unbranched and permanently established on the animal’s head. Wild sheep, for example, continue to grow horns throughout their lives. Horns also are found on bison, cows and goats.
Factors that Determine Antler Size (listed in order of importance)
Genetics - an extremely important component of the deer management formula. However, genetics is just one of the factors of antler development. Age, diet, disease, and injury are often more important contributors to a buck’s antlers than genetics. To understand the role that genetics plays in antler development it is first necessary to understand the contributions other factors make to a buck’s antlers. Most importantly, the animal has to have adequate nutrition. Without adequate nutrition a buck with the genetic background to become the world record whitetail buck might be less than average.
Age - age is the primary factor that determines exactly how big antlers will grow. Antler mass and length increases with age until bucks reach 6 to 7 years of age. In bucks 7 years old and older, antlers mass often increases, while overall length of the main beam and tines declining with each consecutive set of antlers.
Diet - nutritional requirements, particularly those for protein, energy, calcium, phosphorus and vitamins A & D, must also be met in order for deer to achieve maximum antler growth. Adequate nutrition in the months of February and March is especially important, because deer need to replace body fat and muscle lost during winter before antler growth can reach its potential. Dietary protein and energy restrictions will decrease antler volume, beam diameter, main beam length, and total number of antler points grown.
Health (general physical condition, body weight, injury etc.) - body growth and maintenance takes precedence over antler growth. This means that only bucks in good physical condition will reach their full potential of antler growth.
Injury - or damage to the pedicle or velvet may result in the injured antler becoming deformed. An injury to the body can also influence antler growth because energy is used to grow or repair muscle or tissue before it is used to grow antler. Sometimes, a severe injury to the body may result in stunted growth or deformity of the antler opposite side of the body that sustained the injury due to a phenomenon known as bilateral or geo-physical asymmetry.
Factors that Determine Antler Color and Symmetry
Genetics - antler symmetry is determined almost entirely by genetic makeup.
Oxidized blood/local plants - antler color depends partly on the amount of oxidized blood left over from velvet shedding and partly on a chemical reaction between the blood and sap from plants on which the antlers are rubbed.