Since 1970, U.S. dairy producers have reduced the number of dairy farms from 650,000 to 90,000; increased the average number of cows per dairy farm from 20 to 100; and increased total milk production from 120 million to 160 million pounds per year—at the same time that they reduced the overall number of dairy cows from 12 million to 9 million. The dairy industry accomplished these so-called miracles of efficiency by doubling the amounts of milk obtained from each cow from 9,700 to 19,000 pounds per year- just since 1970.

The only way to get more milk out of fewer dairy farms and fewer cows is to push the cows to produce more. But the more milk a cow produces, the greater the chance that her udders can become infected and that she will need antibiotics. To stimulate greater milk production, dairy cows also are treated with hormones. One such hormone—a cow growth hormone known as bovine somatotropin (bST)—is genetically engineered, a process that some people find objectionable. The fivefold increase in the number of cows on a typical dairy farm means that they live under more crowded conditions. Their wastes are more concentrated, they can spread infections more easily, and they need to be treated with antibiotics more often. The antibiotics and hormones can get into the milk and, perhaps, affect human health, and the crowding, infections, and treatment of the cows raise issues of animal rights. Consolidation of the dairy industry to a few big companies raises concerns about corporate control of the food supply. For all of these reasons, and because there is something primal and biological about milk, dairy foods elicit strong feelings.

The USDA has long identified dairy foods as a distinct food group, and for many decades it recommended a not unreasonable (especially if low-fat) two servings a day for adults who like and can eat these foods. In 2004, the dietary guidelines advisory committee recommended three servings a day, thereby endorsing a 50 percent increase in milk consumption. An investigative report in The Wall Street Journal called this change “a major victory for the $50 billion U.S. dairy industry,” and attributed it to a skillful lobbying campaign based on the results of research that had been funded by the Dairy Council, as well as to the financial ties of dairy groups to several members of the advisory committee.