Lucerne, also sometimes called alfalfa is a crop that is a suitable addition to many horses' daily rations. Lucerne usually looks like short-stemmed hay, but is also available in alfalfa chunks or pellets, where the stalks are compressed. Lucerne is a roughage low in sugar and high in protein. Lucerne is widely used in horses as a source of fiber to mix into concentrate feed. This causes horses to chew more and form more saliva which aids digestion.