Usually their teeth start giving out about the time they reach about 6 years old. The area where I live, and grew up is primarily agricultural. We don't see many 400+ lb hogs around here, and there is almost always corn on the ground around here, not to mention native pecan, and millions of oak trees.
I am with another whom said hogs will usually wreck a 3 legged feeder, and not to say the one in the pic won't but, to me he doesn't look like the normal feral hog. I suspect game ranch hog. Maybe not.