A horse that is stabled does not have access to its natural forage feed of grass and this can be compensated for by the feeding of hay. Forage feed provides fibre necessary to keep the horse's digestive system functioning properly. Any hay fed should always be high quality hay free of mould, dust and weeds as horses are very susceptible to moulds and fungi.
It is always best to turn the horse out in a field for at least part of the day if possible to allow natural grass feeding and exercise.
If a stabled horse is being ridden regularly and/or carrying out hard work then concentrate feed may also be required to increase energy, stamina and to maintain condition. It should be remembered that it is natural for a horse to feed little and often and so if feeding a large amount the horse may require its feed to be broken down into two or three small meals during the day.