Deer Dynamics: Antler Growth

Shortly after antler shedding is complete, whitetail bucks of all ages begin the process of developing new antlers. By the sultry days of July, velvet racks grow rapidly, creating distinct formations.

As the days become longer, the process of “photoperiod” takes hold — stimulating more hormonal growth for bucks. More available sunlight allows changes to unfold with a buck’s pituitary gland, producing hormones that significantly contribute to bone and tissue growth. Other natural works play into antler development as well.

A buck’s genetic status and age are major components in the shape and size of antlers. Studies from research biologists have determined that heredity usually controls the rack’s shape, and age dictates to what degree the rack towers and spreads. Typically, at 4½ to 5½ years of age, a buck reaches his mature antler size and fills out nicely. It is also believed that nutrition influences the thickness of a buck’s antlers.

Legumes such as clover and other forage loaded with nitrogen help growing bucks convert nutrients like nitrogen into protein. Having a diverse selection of preferred deer foods gives whitetails the basics of fat, carbohydrates and protein. Yet despite having available nutrition, some bucks during peak antler growth still appear lean and a little skinny when it comes to body mass.

During the summer, bucks’ racks are heavy and filling out with blood-filled velvet growth, yet the antlers are still somewhat out of proportion to their bodies. The reason for this is that wildlife biologists believe nutrients, like calcium, are being robbed from a buck’s bone structure. This nutrition is diverted to the antlers.

Despite bucks having a smorgasbord of vegetative food sources, most still appear smaller in comparison to fall and early winter. It’s not until the antler growth stops that bucks can really start to show substantial body weight — with the exception of well-fed and good genetic monster bucks. With wild free-ranging whitetails, weight during this time is sporadic.

This is one reason it is important to try to implement a mineral-supplement program for bucks of all ages. Calcium and phosphorus are vital for proper antler growth; however, biologists recommend a mineral supplement with other nutrients as well, particularly salt. Even so, it all depends on the soil pH and its mineral content to determine if mineral licks are really needed on a property. Some geographical regions naturally supply good mineral content, while others do not.

During the hot summer days, bucks often retreat to secluded and protected bedding sites. Here, they conserve energy — allowing consumed nutrition to feed their velveted antlers. This is especially true for dominant mature bucks that rely on rack size to intimidate other bucks.

A buck’s velvet is soft and literally feels like velvet. It also acts as a protective covering. Biologists have determined that the velvet is basically a network of blood vessels that carry protein and minerals to the developing antlers. Being pliable, the rack can take on a whole new appearance, particularly if the buck damages a portion of its antlers.

For example, if a growing tine hits a tree limb and doesn’t break off, it can deform and grow downward. This is one aspect of what creates a classical drop tine. It may also take away from the rack becoming symmetrical. Other factors such as quality of nutrition, age, genetics and bodily injuries may also contribute to bizarre antler formations.

Here again, at times velvet racks appear to be out of proportion in comparison to their bodies. Protein and minerals like calcium and phosphorous primarily are going into the growing process of velvet antlers. Yet once the antlers reach their maximum growth, usually by late August, bucks finally begin to gain body weight for the upcoming rigors of the rut.

If nutrition is adequate to good, most bucks, according to various scientific studies, can grow antlers fairly quickly — sometimes as much as a half to even an inch in one day. Beginning in the early spring, the antlers sprout and rapidly start to mature. By late July and August, a full-grown velvet rack is displayed.

However, antler development can be hindered not only by inadequate nutritional quality, but by stress as well. Bucks that are periodically run by predators such as wild dogs or coyotes may experience difficulty in antler growth. Simply, some of their nutritional reserves are going into physical exertion instead of the velvet tissue for growth.

Antler growth is also affected by age. The older a buck becomes, the more difficult it is for him to properly digest nutrients, sometimes because of the loss of teeth. With age also comes the loss of testosterone and other hormones, which in turn adversely affects proper antler development. Also, bucks may have parasites such as tapeworms that rob nutrients from the animal as the years go on.

A buck’s antlers may never take on their full potential due to genetic problems. No matter how much quality nutrition the animal has access to, its rack will only get so big — regardless of its age. Yet by consistently monitoring the deer in a given area through the use of trail cams and on-hand observations, hunters can decided as to whether a particular buck should be taken or passed.

Bucks with bizarre antler growth are usually harvested by hunters to prevent bad genes from spreading. If the buck is allowed to mate, then, in theory, his genes will pass to his offspring, frustrating the labor of working the land for symmetrical whitetails.

Each year, if bucks are able to obtain adequate nutrition and avoid stress, their racks can reach full maturity. Then a buck with normal genes after reaching 3 to 4 years of age can grow the almost exact formed set of antlers from year to year.

Other factors such as proper herd management with balanced buck-to-doe ratios and proper buck age structure are also believed to influence antler growth and formations. These antler shapes and sizes play a significant role in helping hunters abroad to properly identify bucks.

For whitetail bucks to reach their full potential for antler growth and to provide venison for the hunter afield, nutrition is an ongoing reality. It can also dictate the rut. If agricultural grain foods are not available, then deer rely heavily on nature’s bounty of hard mast foods — like the acorn, the next topic.

About Tommy Kirkland 24 Articles
Tommy Kirkland aggressively pursues whitetails with camera and extensive observational work on free-ranging deer. He is a novice turkey hunter; and his articles and photos have been featured in many outdoor publications.