stacwase, I think its supercool that you are living on a farm and Max gets the run of it I know my boy would love that! I disagree with keeping him onleash all of the time - youre basically walking around your backyard, its just larger than most. I would try working on his recall, working on him paying attention to you and focusing on you.. try randomly calling him to you during the walk (reward him with treats and praise), and make sure he stays near you and doesnt just wander off. I wouldnt worry too much about him getting confronted by a deer, cos theyre very fast and agile and can easily outrun your average doggy.

We just moved from a house that was right on a really huge, beautiful golf course and I used to always play ball and frisbee with Gonzo on it at night and I would run with him on the trails after the golfers went home. Kinda a similar situation. there were also lots of deer on the course at night, coyotes and raccoons, and some golfers stayed late so I had to always keep Gonzo in check. Every so often, especially if he was wandering too far, Id call him and run the other way and play chase with him, or call him to me and give him treats when he came. After a few weeks of consistent recall practice, he would stay within 10-20 feet of me at all times on the huge open golf course and still does off leash at any place. I so agree with you, dogs love freedom and they are so happy and content when they can just run with you in open spaces but safety is always a big priority, and dogs kinda get the "call of the wild" if theyre allowed to roam off leash without boundaries or training. Max also looks like a GSD mix, so he probably has some prey drive and will always have that urge to chase, but you can curb it with training. good luck Im definately not going to criticize you for giving your dog lots of good exercise and attention.