I often here hunters talk about "bad genes" when it comes to bucks with a small antler. Is this kind of a running gag for trophy hunters or is this actually true? So, does the size of the antler tell anything about the "evolutionary health" (I really don't know how this is called :) ) of deer?
Genetics is one factor contributing to a deer's antler size, but certainly not the only factor. In many cases, maybe most, it isn't even the most important factor.
Age: Young bucks that aren't fully mature will always have smaller antlers. A deer whose health is declining due to old age may also have smaller antlers.
Diet: Antlers are regrown every year, and this takes a lot of nutrients and energy. A deer that can't get enough minerals and protein will not be growing large antlers. So a deer could easily have impressive antlers one year, then due to a hard winter and a drought ridden spring and summer, have much smaller antlers the next year.
Overall health: Injury, malnourishment and disease will all mean that a buck's body devotes resources to more important functions that antler growth.