The things that horses feed on in Minecraft include sugar, wheat, apple, golden carrot, golden apple, enchanted golden apple, and hay bale, bread.
However, these foods are different in the effectiveness and efficiency, in terms of the health point gain and the time taken to speed up the horse's growth. Hay bales add 20 health points, and it also takes 3 minutes to speed up growth. Enchanted golden apple takes 4 minutes to speed up growth, and it adds 10 health points when fed on by a baby horse.
Golden apple adds 10 health points and takes 4 minutes to speed up growth. Golden carrot takes 1 minute to speed up growth and adds 4 health points. Apple adds 3 health points but takes 1 minute to speed up growth. Wheat takes 20 seconds to speed up growth and adds 2 health points. Sugar adds 1 head points and takes 30 seconds to speed up growth.