The coffee bean (Coffea arabica L.) is used to make one of the most popular beverages in the world and considerable amounts of coffee bean are processed every day, leading to large quantities of by-products that may be used to feed livestock.

The coffee tree is an evergreen, perennial, erect shrub. It is 2 to 5 m high in plantations but can reach up to 15 m in the wild. Stems are opposite, rather thin, first semi-erect then pendulous. Leaves are opposite, oval shaped, 10 to 15 cm long and 4-6 cm broad. They are dark green, with slightly crinkled surfaces (Ecoport, 2009). Flowers are borne in clusters along the branches. They are white, fragrant and star-shaped.

The coffee tree begins to bear fruits 6 to 7 years after planting as a seedling and will be productive for 30-40 years. Average yield in Kenya is 2 to 3 t/ha and 0.5 t/ha in Brazil. The fruit, or cherry, is a reddish 2-seeded berry, 1 to 1.5 cm long and 6 to 7 mm broad (Ecocrop, 2009). The cherry contains 4 anatomical entities: the beans or endosperm (55% DM of the fruit), the hulls or endocarp (12% DM of the fruit), a mucilage or mesocarp also called pulp (5% DM of the fruit), and an outer skin or exocarp (9% DM of the fruit).

Coffee pulp, also identified as coffee fruit without seeds, or beans, is an abundant agricultural by-product. It represents around 43% of the weight of the coffee fruit on a fresh weight basis, or approximately 28% (26-30%) of the coffee fruit on a dry weight basis. The other by-products of coffee fruit processing are the mucilage, about 5% (5-14%) of the dry weight of the fruit, coffee hulls, representing 12% (10-12%) of the weight of the fruit on a dry weight basis and coffee parchment (the parchment is the thin skin of the bean that is removed after bean milling, prior to roasting). There are also instant coffee by-products such as coffee grounds: their ether extract content is fairly high.