The dairy industry is one of the chief suppliers of food for the general population in the modern Westernized world. According to the U.S. Department of Agriculture, 20% of all livestock and poultry products sold in the U.S. market in 2002 were of dairy origin. Fluid milk, cream, butter, cheese, yogurt, buttermilk, and ice cream, almost exclusively derived from cows, represent the major consumer items. Powdered milk, a component in many baked goods and confectionary commodities, also commands a considerable proportion of industrial output. Despite the fact that not all humans can tolerate lactose and thus absorb the nutrients in dairy products, mass-marketed goods from this sector of the Western world have blanketed the globe, and their appeal continues to expand. The reasons for this ...