When you are going to an event, whether its eventing, showjumping, dressage or showjumping don’t be tempted to increase your horses hard feed (grain, nuts, cubes, etc) because you are going to ask your horse to work hard. With decreased activity due to transport, stabling at competition, etc if anything you may actually want to consider maintaining your forage intake but actually cutting down you hard feed. Too high a hard feed intake for the level of work is a major risk factor for tying-up (exertional rhabdomyolysis, azoturia, Monday Morning disease).