Well checked out the pictures over lunch on my buddies computer. Just my take on it but I'd say that the bigger one is 5.5 years old, possibly as Hoytman said 6.5. He has a bit of a dewlap and a stocky look proportional to his legs. They also don't get that belly till they are 5.5 or 6.5.
The other one I would say is 3.5 years old. He is heavier muscled in the shoulders than a 2.5 year old which gives him a bit of that broad shoulder/thin waist appearence. His antler mass is too good for a 2.5 yr old unless the velvet is making them look a lot bigger than they are. While we don't have a head on shot his antlers look like they would be on the outside of his ears in width which a 2.5 year old with typical antler symmetry won't be.
I always like this pic when showing ages. It is not from here so the deer are kind of dainty
but it gives a good overall comparison between a 1.5-3.5yrs old.
Here is a NB 1.5 and 2.5 yr old... look closely at the 2.5 yr old and while ours are bigger the display the same characteristics.
