Perri's Pony Anti-Grazing Device is an excellent product to prevent ponies from grazing.  The anti-grazing device attaches to the saddle and the bit, applying upward pressure on the bit when the pony puts its head down to prevent grazing while being ridden. This is a great product to have on hand for beginner riders, especially lessons in a grass ring or when you head out hacking and trail riding. Nylon. Amish made.