If you’ve taken a close look at a boiled deer skull, or one that has lain in the woods for some time, you might notice a faint line just below the antler burr. This line is a unique layer of cells called osteoclasts, and where the antler will separate from the skull when casting occurs.
Antler casting takes place when a buck’s testosterone level decreases. Next, the osteoclast layer of cells begin to absorb calcium from the antlers, causing the bone to weaken and become grainy and chambered. When this happens, little more than a light tap or the weight of the antler is all it takes for the antler to fall off the buck’s head. The rough, porous bottom of the antler vividly shows what occurred when the osteoclast layer of bone broke down.
In most cases, the cast antler has a convex base with a depth anywhere from 1/8- to 1/2-inch. This leaves a corresponding crater in the pedicule layer of bone. After the antler is cast, the exposed bone bleeds, causing a scab to form. The scab then heals from the outside of the pedicule to the center. When fully healed, the top of the pedicule is covered with a brownish-gray skin, with a small light-gray dot in the center of the pedicule.
Many people often ask whether bucks feel pain when casting takes place and how fast it occurs. Many assume that bucks feel pain when their antlers are shed. This is likely not the case. In one study, researchers discovered that whitetails, when under extreme stress, produce naturally high levels of B-endorphin (especially in fall), which supports a high pain threshold and rapid wound healing. Endorphins consist of morphine-like chemicals from the pituitary gland, allowing the animal to control pain. In addition, bucks experience rapid buildups of steroids and androgens in the bloodstream. This promotes healing, helps manage stress, and suppresses and prevents inflammation.
After closely observing the casting process during the past 20 years, I believe bucks feel no pain when they cast their antlers. What I have observed is that bucks are startled and curious when their antlers drop from their heads. A buck might lunge away from the cast antler as it hits the ground, and then cautiously come back to examine it. In some cases, I’ve even seen the buck lick his shed antler. The speed at which casting occurs is very interesting.
For starters, the breakdown and granulation of the osteoclast layer of cells occurs rapidly. For example, I’ve been able to grab one of our pen-raised buck’s antlers one day, finding it firmly attached to the buck’s head. Then, less than 48 hours later, I’ve discovered the buck has cast one or both of his antlers. This rapid antler breakdown and casting has been documented numerous times with pen-raised deer.
Of the many bucks I’ve raised, only two have dropped both antlers at the same time. In all other cases, the second antler was cast 12 hours to four weeks later. On average, most bucks have carried the second antler four days to seven days after casting the first antler, which illustrates why it is so difficult to find a matched set of sheds.