Wildlife managers looking to maximize their deer herd’s antler production will reach their best results by maximizing the nutrition available to the entire herd, according to whitetail biologists at Mississippi State University’s Deer Lab.
Biologists at MSU have been studying whitetail deer both in the wild and in controlled environments since the 1970s, solving problems facing natural resource agencies, managers and private landowners. Along the way, their research has gleaned information valuable to hunters of every stripe.
Bucks grow a new set of antlers every year, which allows them to invest in larger sets of antlers as they get older. Scientific studies of captive deer have shown larger antlers are preferred by does and also improve the fighting capabilities of bucks.
“Young bucks emphasize growing larger bodies because, regardless of antler size, they need larger bodies to fight other bucks,” Dr. Steve Demarais, with MSU, says. “Young bucks grow antlers, but antler growth really takes off in their third, fourth and fifth years because they’ve reached their mature body size and, physiologically, can invest in growing bigger antlers to enhance their fighting capabilities.
“Antlers are grown primarily and specifically for fighting other bucks to establish dominance and breeding priority. People often assume antlers are for defense against predators, but they’re specifically for use against other deer.”
Antler growth is cyclical, and it’s thought there’s a spike in a hormone in a buck’s body that initiates its beginning each year. This period coincides with a time of low testosterone production.
Time to grow
The two main components mandatory to the in antler-growing process are protein and minerals, the latter being a combination of calcium and phosphorus and other micronutrients. Bucks need a good protein diet because protein is the framework of the bone growth to come. Antlers, Demarais says, are effectively protein structures with minerals attached.
Bucks drop their antlers in late winter to early spring, after the breeding cycle is thoroughly completed. In the Southeast, this occurs in late February and early March. The pedicles from which the antlers grow and, then, are subsequently dropped, heal. Then roughly three weeks later, growth of new antlers begins.
It tends to be very slow at first. During the first months, when the antler bases are being formed, the growth rate yields an inch of antler every few weeks. The going is slower here because the process is producing mass relatively higher than will be generated down the line. Once the process gets going at its highest growth rate in late June and July, a mature buck can add an inch of beam length every week.
That is a critical nutritional time for the entire deer herd, for bucks growing antlers and does growing babies and producing milk.
Summer nutrition is often overlooked by those managing whitetails, simply because the world is green and there seem to be many naturally-occurring options available to the deer, but the managers’ contributions here are as critical as any time of the year. It’s very important to have active habitat management to produce this good summer nutrition. Deer always need quality forage.
Antler growth pulls minerals from bones in the bucks bodies to put into antler, because they can’t eat and process these minerals quickly enough to keep up with antler growth otherwise, but bucks replace these minerals in their skeletons through diet year round.
“Just as with human beings, deer use minerals in many phases of their processes, making everything work as they’re supposed to,” Dr. Bronson Strickland, with MSU, says. “There is a tremendous amount of mineral mobilization that goes on with growing antlers every year, primarily calcium and phosphorus. What’s fascinating to me, when a buck is growing antlers every year, they temporarily go through osteoporosis, extracting minerals from their bones to grow antlers. Over time, through diet, they later replenish these minerals in their skeletons.
“The best way to supply the minerals a deer herd needs to thrive is to concentrate on overall habitat improvement, so that a buffet of nutritious food is always available to them, and they can pick and choose what their bodies tell them they need through the cravings and preferences for food that drive them.”