Oats. Grains of oats (Avena sp.). Oat grains consist of a digestible groat (seed) held inside an indigestible hull. They are commonly used in breakfast foods such as cereals and porridges. They have many other uses, such as cattle feed. Oats are high in protein and are a good source of vitamin B1 (thiamine). Another use of oats is the production of furfural from the hulls. Furfural is used as a solvent in many refining industries.