Congratulations! - I'd estimate it to be 2-1/2 - You can verify this by checking the third premolar - If it is older than 1 yr, 6 months, it should have 2 cusps - if 1.5 old - it will have three cusps.

Even if its only 1.5 - it looks to be a cull bull, or one recovering from a summer illness. It would appear the rack is very deficient in minerals, and soft. The hole is definitely from an injury while in velvet. Sometimes an injury in velvet can result in a hole that will extend into the main beam for several inches, because of the peculiar way antlers grow.