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 milk" and "A2 MILK" are trademarks held by the a2 Milk Company. A2 Corporation licensed patents filed in the 1990s by the New Zealand Dairy Board, and filed its own patents on genetic tests to determine what form of beta-casein cows produce in milk, and concerning potential adverse health consequences of A1 milk. The a2 Milk Company holds a worldwide suite of intellectual property to protect its business products, trademarks, trade secrets, and patents covering the genetic test and methods to develop A2 producing herds, as well as methods to check the protein content and fatty acid content of milk,