United States raw milk debate prior to symptom onset." Milk collected or stored in unsanitary conditions may harbor a host of disease-causing organisms (pathogens), such as "tuberculosis" (Mycobacterium bovis), the bacteria "Campylobacter" (Campylobacteriosis), "Escherichia" E. coli O157:H7), "Listeria" (Listeriosis), "Salmonella" (Salmonellosis), "Yersinia" (Yersinia enterocolitica), and "Brucella" (Brucellosis). Pasteurization consistently removes all of these pathogens, though they can be reintroduced if the product is handled carelessly. Thus dairy farms that pasteurize their milk can have unsanitary facilities without the attendant outbreaks of disease that would occur if a raw milk dairy kept its herds in similar unsanitary conditions. People with weakened immune systems, such as elderly,
A2 milk is impossible to determine what component or components of milk might be responsible for these effects, and it is unlikely that the expensive and complex research to determine the answers to these questions will ever be conducted. Milk with predominantly A2 protein is not a milk substitute for infants with cow milk protein allergies. The a2 Milk Company claims that people who experience discomfort drinking ordinary cows' milk may experience relief when they switch to milk with predominantly A2 protein. In the 1980s, some medical researchers began to explore whether some peptides (including peptides from casein) that are created during