Donkey manure can be composted, however, its best if collected while it is fresh.
Although not quite as good as cow manure, it is a fine additive if added to food waste and other composting materials. It must be composted before use.
A compost pile does two things, 1) it heats up the manure, killing any weeds seeds that are present. 2) It rots down to a fine loam which is good for the plants.
A composting bin is not essential, but does help to retain the heat and keeps the area looking clean.