Reasons For Equine Turnout?

To eat grass, for exercise to keep them fit and their bowels moving, for the company and social interaction with other horses, for mental stimulation, to stop their joints from seizing up, to burn off energy, to keep them warm in winter (a moving horse is warmer than a still 1), because they aren't meant to be cooped up indoors it goes against their nature in the wild they would constantly be outside, because being cooped up in a stable drives them mad and they develop vices and become more diffucult to ride because it is the only chance they get to burn off energy. Effects would be agression to stable mates and people, impact colic from no exercise which stops their bowels working properly, seized up joints , joints not developing properly in young horses, Vices like cribbing, wind sucking, weaving , box walking, door kicking, boredom, depression, barging out the stable, being dangerous to ride and lead anywhere for a small stable they would still apply, but probably no room to box walk, and they might not be able to lay down , the joints would seize up more ,and they would probably get a bad back., It is also thought that being cooped up all the time could be 1 of the factors that causes cushing's disease. And being kept in all winter over fed and over rugged is thought to be 1 cause of laminitis. And circulation problems would also happen.