Ive messed with horses for over 50 years. and Im of the opinion a horse only needs enough grain to allow you to catch him. The wild BLM horses don't get grain or great feed. and they thrive & reproduce faster that they can adopt them out. My horses ate whatever hay I bailed for the cows & goats. and much of it contained fescue. ant they never got sick and had good hooves. of course they weren't high blooded hot house horses. I even adopted 5 BLM horses and broke the to ride. and bougHt two more Blm horses from a neighbor who adopted them and was scared of them. the grain bucket causes more harm than bad hay. I still have a dog killing jenny and she eats whatever hay I bale. She has a colt every year.