feeding hay after exercise

Question
hello sir, why should  a horse be fed hay or turned out as soon as it returns to the barn from exercise irrespective of any gait (trot, canter, seat hack, gallop)? why grains and bran shouldn't be fed immediately?

Answer
hi-- i am very particular about feeding any horse any food after a workout etc. you need to let a horse cool out very well before you give them anything to eat or drink. at least 1 hr   you can cause a horse to founder if you do something like feed him too fast after he is cooled out. and hay can choke him because he is hot and has so saliva when chewing the hay causing it to be too dry  to SWALLOW. thanks ED HESS