My neck of the woods, a 6 year old deer is at his peak-antlerwise-generally. They begin to go downhill in growth after that, but still live. KANS and I have found many a gnarly shed or even skull with rack that we have estimated to be over 7 or 8 years old. Thing is, the older they get, the more instinct, the less you see of them. They don't get old or big by regularly parading themselves openly

Just my thougts.