In 1900, the average dairy cow in America produced 424 gallons of milk each year. By 2000, that figure had more than quadrupled, to 2,116 gallons. In this episode of Gastropod, we explore the incredible science that transformed the American cow into a milk machine—but we also uncover the disturbing history of prejudice and animal cruelty that accompanied it.
Along the way, we’ll introduce you to the insane logic of the Lifetime Cheese Merit algorithm and the surreal bull trials of the 1920s. This is the untold story behind that most wholesome and quotidian of beverages: milk. Prepare to be horrified and amazed in equal measure.

New and Improved Bulls
Something extremely bizarre took place in the early decades of the twentieth century, inspired by a confluence of trends. Scientists had recently developed a deeper understanding of genetics and inherited traits; at the same time, the very first eugenics policies were being enacted in the United States. And, as the population grew, the public wanted cheaper meat and milk. As a result, in the 1920s, the USDA encouraged rural communities around the U.S. to put bulls on the witness stand—to hold a legal trial, complete with lawyers and witnesses and a watching public—to determine whether the bull was fit to breed.

Livestock breeding was a normal part of American life at the dawn of the twentieth century, according to historian Gabriel Rosenberg. The U.S., he told Gastropod, was “still largely a rural and agricultural society,†and farm animals—and thus some more-or-less scientific forms of selective breeding—were ubiquitous in American life.

Meanwhile, the eugenics movement was on the rise. Founded by Charles Darwin’s cousin, Francis Galton, eugenics held that the human race could improve itself by guided evolution—which meant that criminals, the mentally ill, and others of “inferior stock†should not be allowed to procreate and pass on their defective genes. America led the way, passing the first eugenic policies in the world. By the Second World War, twenty-nine states had passed legislation that empowered officials to forcibly sterilize “unfit†individuals.

A "Better Sires: Better Stock" accredited dairy herd.

Combine the growing population, the desire for cheap meat and milk, and the increasing popularity of eugenics, and the result, Rosenberg said, was the “Better Sires: Better Stock†program, launched by the USDA in 1919. In an accompanying essay, “Harnessing Heredity to Improve the Nation’s Live Stock,†the USDA’s Bureau of Animal Industry proclaimed that, each year, “a round billion dollars is lost because heredity has been permitted to work with too little control.†The implication: humans needed to take control—and stop letting inferior or “scrub†bulls reproduce!
Hear Ye! Hear Ye! Welcome to the Court of Bovine Justice
The "Better Sires: Better Stock" campaign included a variety of elements to encourage farmers to mate “purebred†rather than “scrub†or “degenerate†sires with their female animals. Anyone who pledged to only use purebred stock to expand their herd was awarded a handsome certificate. USDA field agents distributed pamphlets entitled “Runts and the Remedy†and “From Scrubs to Quality Stock,†packed with charts showing incremental increases of dollar value with each improved generation as well as testimonials from enrolled farmers.

The "Better Sires: Better Stock" certificate, awarded to farmers who pledged to use purebred rather than scrub bulls.

By far the most peculiar aspect of the campaign, however, came in 1924, when the USDA published its “Outline for Conducting a Scrub-Sire Trial.†This mimeographed pamphlet contained detailed instructions on how to hold a legal trial of a non-purebred bull, in order to publicly condemn it as unfit to reproduce. The pamphlet calls for a cast of characters to include a judge, jury, attorneys, and witnesses for the prosecution and the def