Horses kept on stables needs more attending than that of those kept grazing on the field. More or less stabled horses are those that are used in horse racing which is on its own animals that should really be taken cared of extra specially.
Horses on the area get the practice they want through running around the area they're stored in however horses used for racing, and well can we say, do not require much exercise apart from those that they have run the paths.
Most likely stabled horses require nutritional supplements, better meals and cleaner surroundings. You can check out https://www.taylormadeequine.com/product/pre-race-activator/ if you're looking for racehorse supplements.
It's a fact not quite widely known that horses, their digestive tract, it's intended to take little by small amounts of food.
They are not like pigs that may munch daily with only about anything sheep's and cows which consume the unlimited quantity of bud.
That's the reason why they're fed by the program they consume through times we people also eat and when they're like racing, they have to stick to a strict eating regimen to maintain their body healthy and fit.
Additionally, another thing to note is that horses, even though very sensitive how much food they could eat, they're far more sensitive in exactly what time they need to be fed.
If you feed them regularly at 8 am every day, you shouldn't ever alter that regular impulsively.