It's antler growing season (and will be for the next couple of months) for white-tailed deer. They'll grow them out, shed their velvety coat, and use them for battle in the winter. Like spears, the antlers on the tops of white-tailed bucks heads are used for display and fighting.
Proper nutrition and genetic makeup is necessary for growing the biggest pair.
Here's one little buck starting that has been already growing his antlers since a few weeks ago.