Alot of questions. How long has it been between moves? How many horses were in his herd before and how many now? Did he have a buddy before? What kind of watering system was in place before and now? How was your hay provided before and now? And feeding, was there a change in how and how much or type of feed? He may not be able to get to hay if there is a dominant in his field but after a few days he should be allowed unless the dominant is bully and he is low man. Maybe he could be moved to another herd. Is the waterer working properly, does he know how to use the waterers? Is is cold water, maybe electrolytes would help. How is the footing different? And then finally how are the folks that handle him daily for feeding and turnout? As important as all of the other answers this one is too. If their energy level is high, he has enough new stuff going on, this just adds to his stress. One of the other posts recommended spending time at the farm, check it out. Just observe the dynamics and interaction, you might find out what he is trying to tell you. Good Luck!!