Yellowstone Park bison herd a highly contagious zoonosis caused by ingestion of unpasteurized milk or undercooked meat from infected animals, or close contact with their secretions. Brucellosis occurs naturally in the Yellowstone Bison Herd and the normal winter migrations of bison outside the park have raised concerns that Brucellosis infected Bison may infect cattle. The United States government has programs to eradicate brucellosis in domestic livestock. Since 1934, an estimated $3.5 billion in federal, state, and private funds has been spent on brucellosis eradication in domestic livestock. Over the years, the National Park Service and states bordering the park have implemented various plans to
Milk via ultra filtration, which removes smaller molecules such as lactose and water while leaving calcium and proteins behind. Milk produced via these methods has a lower sugar content than regular milk. In areas where the cattle (and often the people) live indoors, commercially sold milk commonly has vitamin D added to it to make up for lack of exposure to UVB radiation. Reduced-fat milks often have added vitamin A palmitate to compensate for the loss of the vitamin during fat removal; in the United States this results in reduced fat milks having a higher vitamin A content than whole milk.