According to dairy farmer Rupert Cyster (interviewed in lesson 1.6), a balance of nutrients in a cow’s diet leads to milk with superior qualities for producing milk foam for latte art. Farmers usually provide three types of feed to their cows, year-round where possible: pasture, silage, and cake.Because cows are big animals and their hoofs churn up the pasture when it is wet, most cows spend the wettest months of the year (i.e., the winter months) indoors. This is an important time for the dairy farmer to manage soil nutrition. Grass is one of the most valuable assets of a dairy farm because it is the primary source of food for the cows. Just as on a coffee farm, the soil on a dairy farm inputs need to be balanced and sustainable, with the aim of producing great pasture. A combination of heavy rain and hoof tracks can damage pasture and lead to erosion. But during the winter, cows eat silage, a fermented, high-moisture form of animal feed instead.