It's a slow feeder. The barrel holds a hay bale, which stays dry when the lid is on tight. The net allows for the hay to be pulled down little bit by little bit. (Who has a hack for slowing grain/beet pulp consumption?
Exercise - i like adding in the phase's and i like the build from controlled trot to gradual release and stretch at the oxer. Do nothing but balance the horse. I'd also like to see this done in reverse order. from stretch, to coming back into control a