Feather beds take a bit of a bashing but they can be used as something else if the feathers are sound.
Clean the Feather bed
Before you can decide what to do with your feather bed you should wash it. Use a large commercial machine with a gentle cycle. Take as long as it needs to dry the feather bed. Feathers have to be bone dry or they will start to rot.
If, after washing and drying the feather bed, you still do not want to use it, consider making a couple of feather pillows out of it. Not only will this give you two more pieces of luxury bedding, it will give you the chance to confirm the state of the feathers.
If not really suitable for pillows, feathers will make a very nice pet bed. The condition of the feathers, as long as they are dry, will not bother the pet.
If the feathers really are not good enough to be reused, they can be used in your compost heap or dug into new flower beds before replanting. Feathers make ideal mulch when damp but end up all over the garden if they dry out.