Alfalfa is widely grown throughout the world as forage for cattle, and is most often harvested as hay, but can also be made into silage, grazed, or fed as greenchop. Alfalfa usually has the highest feeding value of all common hay crops. It is used less frequently as pasture. When grown on soils where it is well-adapted, alfalfa is often the highest-yielding forage plant, but its primary benefit is the combination of high yield per hectare and high nutritional quality.
Alfalfa is high in protein, calcium and other minerals, vitamins in the B group, vitamin C, vitamin D, vitamin E, and vitamin K. The sun-dried hay of alfalfa has been found to be a source of vitamin D, containing 48 ng/g (1920 IU/kg) vitamin D2 and 0.63 ng/g (25 IU/kg) vitamin D3.