Children that grow up on farms have fewer allergies than children growing up in city environments. This protection against the development of allergy is associated with the consumption of raw farm milk. Heated farm milk does not have this effect, indicating that (non-denatured) milk proteins are responsible for this effect. The consumption of normal bovine colostrum protects immunocompromised people against infections. Bovine milk proteins have immunological effects on human cells. Currently, raw milk is not commercially available and cannot be used for controlled intervention studies because of the potential presence of pathogenic microorganisms. Alternative milk-processing technologies are needed to preserve immune active milk proteins that can improve immunity in children.