Like protein derived from cow's milk, the two major proteins in goat's milk are casein and whey. Some people are allergic to a specific casein protein in cow's milk; this has prompted the recent development of goat's milk protein powders. Also, most of these protein powders come from goats that are not fed pesticides, herbicides, growth hormones or antibiotics. Another advantage is that the casein in goat's milk is easier and faster to digest than the casein in cow's milk.