I'm not that familiar with Texas deer but I'm going to say 4 1/2 years old tops. Older deer get a big gut, roman nose, grayish white around the muzzle and between the eyes. They also seem to carry more weight in the haunches and neck area, almost appearing out of balance. The hide around the eyes gets heavy and their head takes on a wide triangular shape. You see less muscle expression and a swayed back. I got a pic of a 7 1/2 year old I killed several years ago. If I can find it I will try to scan it and post it. It shows the above characteristics pretty well for a dead deer. He also looks about 16" wide in the pics. He is out to the ears and thats usually a 15 to 16" buck in my neck of the woods.