Never change the horse's ration suddenly. Allow a minimum of two weeks for any adjustment. All horses should have access to a trace mineralized salt block. Losing pasture time increases boredom in horses. Stemmy, non-moldy hay of less quality can give the horse something to pass the time with.
Small amounts fed often is best.
Shelter should be available for the horse. Horses do not necessarily need an enclosed barn, but they should have access to a three-sided shelter with a roof. Show horses with short hair coats should not be turned outside in bitter cold weather unless they have the protection of a blanket and windbreak. Maintain a good dental program and parasite control program. Teeth should be checked for wear and floated if needed.