ORIGINAL: dukemichaels
That buck is without a doubt 3.5 and perhaps a bit older even. But 3.5 yr. old would just about be my best estimate.
A 2.5 yr. old will have much more of a squared head. A thin body with practically no sagging belly.
Neck size is not determined by age. Neck size develops as the breeding season draws nearer. Even a 1.5 yr. old will get a larger neck.
I will argue that neck has nothing at all to do with age as most all of the older bucks I have pics of no matter the time of year have nice thick muscular necks.
I just have a hard time calling him 3.5 from these photos....
Like I said a visual will tell me everything I need to know.