You might consider the results of what you are shooting on it's palatability too. A young tender fawn is always better eating than an old buck in rut.
I killed a very old doe a couple years ago that I turned everything but for a little bit of jerky and the back straps into hamburger. I don't know for sure, but My best guess was that she was past ten. I've only ever had one big buck that was good eating. Some are just good for stew/grind meat. I've never had a bad yearling/fawn in 60 years though.
