How do you guys deal with herd bound horses, besides the obvious, pasturing them away from the others. I've been riding my friends horse, and he is super herd bound. The only ring we have to work in is in plain sight of his herd mates, and she boards him and there is no where to pasture him by himself. I am wondering how I can ride him, and get his attention on me instead of this buddies!
(edited to add)
Also, I am not sure this has something to do with it but, for the first 4-6 years of his life he was always the only horse on the farm where she got him from. Since she got him he has been with other horses, turned out basically 24/7.