QUESTION: Bob, we have a lease in Alabama, and over the years we've noticed virtually all our racked bucks seem to have broken tines. I realize that during the rut bucks are pursuing does and might have occasional fight, but it would seem that every now and then we'd take one without a broken tine. Could this indicate some sort of mineral deficiency? It has been years since we've taken a buck without broken tines. - Kenneth R.
ANSWER: Antlers begin forming as living bone with an internal circulatory system and external covering of velvet. Toward the end of their growth cycle they go through a process called mineralization. Circulations ceases, living tissue dies and you're left with dead bone, which is predominantly calcium, but also contains other minerals.
Deer obtain these minerals through plants, which draw them from the soil.
It would seem logical to conclude that a high incidence of antler breakage could be the result of a mineral deficiency.
Either the minerals are not present in sufficient quantity, or the environment lacks sufficient conditions for plants to take up soil nutrients and convert them to a form that is useable by deer.
Surprisingly, there hasn't been much research on the subject.
One study by Texas Tech University was inconclusive. They found no direct correlation between mineral content and the likelihood of breakage. However, the authors noted that there is a direct correlation between osteoporosis in humans and elevated levels of aluminum. They also noted an inverse correlation between rainfall and aluminum concentrations in deer antlers; higher aluminum concentrations in dry years could lead to more breakage.
The structure of your local deer population could also be a factor.
The closer the sex ratio is to 1:1 the greater the competition among bucks, which leads to more fighting, which results in more breakage.
One reference I checked also suggested having a higher age ratio - more older bucks - could also have the same result.
My observations have been somewhat different.
Age doesn't seem to matter. If you have a lot of bucks of any age competing for does, they'll be more aggressive interactions, increasing the chances for antler breakage. I haven't followed weather patterns, but have also observed the frequency of breakage seems to vary from year to year, being higher in some years and lower in others.
If you want to reduce the degree of breakage, you might consider putting out mineral supplements. However, you should also make sure there are sufficient water sources available throughout the year.