Dairy industry in the United States

The dairy industry in the United States includes the farms, cooperatives, and companies that produce milk and cheese and related products, such as milking machines, and distribute them to the consumer. By 1925, the United States had 1.5-2 million dairy cows, each producing an average of 4200 lb of milk per year. By 2007, there were 9.1 million dairy cows but their average milk production was over 20,000 pounds per year, with eight pounds per gallon.

History
European dairy practices varied from place to place, and immigrants to the United States would work together to import and improve on the best Europe traditions. One result was a variety of dairy practices across the United States.

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The fresh milk habit began to develop in the middle of the nineteenth century in New York City. Before then, pitchers of milk fresh from the cow were a rarity on urban tables. Milk was consumed as cheese, butter, or "clabbered milk." The new problem was bad milk–"white poison.” The sanitary and child-welfare movements collaborated and identified dirty, spoiled, or adulterated milk as among the causes of the massive infant mortality rates. Before 1900 the milk New Yorkers drank was produced in the city by cows fed distillery waste, or swill. They were packed together in filthy barns of the sort that could not withstand exposure in the city newspapers. The solution was to shut down the city operations and rely on fresh pasteurized milk brought in daily by train. By  1917, 5 percent of American cattle were infected with Mycobacterium bovis (bovine tuberculosis  or BTB), including 10 percent of dairy animals and 1–2 percent of range cattle. The rates were going up. Around 1900 15,000 Americans, mostly children, died each year from BTB and many more suffered pain and disfigurement.  Threatened by a sales cutoff ordered by urban public health officials, Vermont state government officials launched  and innovative eradication campaign bovine tuberculosis on farms. They made use of the latest German research, and thereby kept the New York City and Boston markets. Vermont was exceptional, for across the country many farmers strenuously resisted bovine tuberculosis eradication as an expensive violation of their right to farm. A 1901 editorial in Breeder’s Gazette reflected the rhetoric of the antis:
 * For years the noble army of tuberculin squirt gun manipulators has been marching up the hill, beating tom-toms and brandishing the pole-axe, crying ‘Kill, Kill.’ This fierce and bloodthirsty campaign against our herds has been waged on the disputed assumption that tuberculosis in cattle is a menace to the public health....Servile worshippers of asserted authority, the half-baked scientists and zealots of the squirt gun brigade have pushed their work of destruction until it has mounted to millions of dollars.

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21st-century farms
There are 40,200 dairy farms in the United States, down from 111,800 in 1995. In 2017 the top five dairy states are, in order by total milk production; California, Wisconsin, New York, Idaho, and Texas. Dairy farming remains important in Florida, Minnesota, Ohio and Vermont.

Herd size in the US varies between 1,200 on the West Coast and Southwest, where large farms are commonplace, to roughly 50 in the Midwest and Northeast, where land-base is a significant limiting factor to herd size. The average herd size in the U.S. is about one hundred cows per farm but the median size is 900 cows with 49% of all cows residing on farms of 1000 or more cows.

Production by state
Production of milk per state in 2019 was as follows: