From Works in Progress, December 5:
What do cryogenics, butterfat tests, and genetic data have in common? They’re some of the reasons behind the world’s most productive dairy cows. Here’s how it all started.
No matter where you are in the world, there’s a good chance the milk or cheese you’re buying is the product of the US dairy industry. Even if it didn’t come from American cattle, the cow that produced the milk could well have been inseminated by an American bull.
The United States has been the world’s largest supplier of cattle genetics since at least 1992. In 2022, the US exported $295 million in bovine semen, 47 percent of the world’s exports. Few countries even come close to this market share: the next biggest exporters are Canada at 14 percent and the Netherlands at seven.
America’s cows are now extraordinarily productive. In 2024, just 9.3 million cows will produce 226 billion pounds of milk (about 100 million tons) – enough milk to provide ten percent of 333 million insatiable Americans’ diets, and export for good measure.
And that’s despite the fact that none of the cattle breeds the US exports are indigenous to the country. The world’s most popular dairy cow breed, the Holstein-Friesian, hails from the border between the Netherlands and Germany; the Jersey and Guernsey dairy breeds both originate from islands in the English Channel.
In many low-income countries, livestock products, including dairy cows, are critical for providing both nutrition and farming livelihoods. As a result, the US’s role in the global livestock genetics market lends it an outsize role not only in the genetic improvement of cattle but as an arbiter of rural development worldwide.
How did the US achieve this? In a word: data. This is the story of how the power of big data, combined with an ambitious public-private partnership between dairy farmers and the US Department of Agriculture, enabled the US to engineer the modern dairy cow and transform the dairy industry.
When looks aren’t everything
Like many things in the United States, the dairy industry was an import. Dutch settlers were importing their own breeds of cattle to the United States as early as 1621 and the first documented importation of a Holstein-Friesian cow was in 1852. Similarly, English immigrants introduced Jersey and Guernsey cattle to the US between 1840 and 1850.
Over time, crossbreeding between cattle led to a natural breakdown between breeds, making the lines between breeds increasingly unclear. However, many dairy farmers felt a desire to preserve the traits of the breeds they brought over to prevent the characteristics they liked from being changed over time. Only making crosses within the breed was, for farmers at the time, the best way to do this.
Enter the breed association. Breed associations set the breed standard: what a cow should look like to belong to that breed. As an example, a University of Illinois extension publication as late as 1942 reports that any color other than black and white would disqualify a cow from being considered Holstein-Friesian. These associations tracked the lineage of each cow in herd books, and records of each cow’s parents and children, which were made freely available to members of the association. The herd book also functioned as a certification process, preventing unscrupulous breeders from inflating the pedigree of their cattle (as happened, for example, in 1789, when French breeders shipped cattle to the island of Jersey, then sold them on to England as ‘Jersey cattle’).
As the crossbreeding of cattle continued, breed associations began to emphasize the importance of purebred cattle, or crosses of the same breed. Cattle crossed between multiple breeds were considered inferior and referred to as scrub cows. For centuries, this was the standard of genetic improvement: purebreds over scrubs. To maintain the purity of the breed, farmers were encouraged to cross only within the cattle families that the breed association deemed acceptable.
To determine the best animals within a particular breed, the associations also needed a way to appraise their physical characteristics. Thus began the institution that is the cattle show, where experts appraise cattle relative to the breed association’s standard. Dairy cattle would be judged on their body width (important for birthing calves), size (important for a high volume of milk production), and even the shape of their udders (important to ensure the udders would stay off the ground as the cow aged so it could milk longer).
With the benefit of modern genetic science, we now know that this is not a particularly effective strategy for improving dairy cattle....
....MUCH MORE
