June has been celebrated as National Dairy Month since 1937 to promote drinking milk and to stabilize the dairy demand when production was at a surplus.
California's dairy reign began in the 1850s north of San Francisco, where the Point Reyes region joined New York state as the two centers of commercial dairy production in the country. In 1880, the California census counted 210,000 milk cows producing nearly 12 million gallons of milk.
Food safety and quality have been priorities in the dairy industry for more than 100 years. In 1891, the Dairymen’s Union of California was founded to improve distribution both inside and outside the state, and to set quality standards and benchmark prices. The Dairymen’s Union created the State Dairy Bureau, which promoted dairy research and education at the state's agricultural colleges and inspected dairy operations to verify that they met state health standards. The partnership and cooperation between dairy farmers and the government helped California's dairy industry become an economic success.
A search for "dairy" in UC Merced Library's California Agricultural Resources Archive (CARA) yields nearly 400 digitized resources documenting the state's history of research and development in the dairy industry. Annual narrative reports of county agents, milk flavor and production cost surveys, cow census records, and dairy industry newsletters provide a picture of how California's dairy boom came to be.
In 1922, tester G. Wolf of the Farm Bureau Dairy Department of San Joaquin County reported 472 cows tested, 39 of which produced over 400 pounds fat and made the state honor roll of butter fat production. These highs spotlighted the value of dairy animals and the efficiency of herds through improved knowledge and record-keeping of the milk and butter they produced.
Row of cows, circa 1920. Merced County UC Cooperative Extension Records.
In Merced County, the number of milk cows numbered 96,000 in 1946. Modern equipment made for more efficiency and larger herds, while improved breeding, feeding, and management upped production per cow.
"The Dairy Picture." Agricultural Resources and Trends in Merced County: Annual Report 1958.
Dairy Tales, published by UC Agricultural Extension’s Dr. John W. Seibert in 1983, presents a county-by-county statistical picture of the dairy industry, and a window into milk's starring role in California agriculture. That year, California dairy farmers earned $1,885,472,000 from the sale of milk, and the average dairy farm sold 14,202 lbs. of milk per day—producing enough milk in one day to meet all the dairy product needs of a family of four for over six years. A decade later, California became the leading dairy-producing state in the nation.
In 2020, the value of milk produced in Merced County alone totaled $1,050,940,000 (Source: California County Ag Commissioner's Data Listing).
Group with prize-winning cow, circa 1963. Merced County UC Cooperative Extension Records.