I really love cows, but where does this passion come from? Growing up on the farm, you just assume your love of animals comes from spending time with them. But then I found it in my DNA.

I grew up learning herdsmanship skills from my dad and grandpa. Learning how to read cows and know what they are thinking or feeling happens over time and becomes second nature. My dad shares a similar passion for cows and has been working with them his entire life. I know my dad has a real passion for these animals because he rarely leaves our farm. The cows are part of his family. Strangely, my dad’s passion for cows is not a family anomaly because my grandpa was another great cow man. He emigrated from the Netherlands and brought his love of cows to California in the 1950s.

Dairy farming seems to be a family passion because my forefathers shared the same passion, being dairy farmers in the Netherlands for generations. We’ve been able to document our family’s passion for cows in the Netherlands as far back as 1520.

The Dutch have a strong tradition of dairy in their country, and tending cattle seems to be a cultural obsession. The pastoral climate of the Netherlands made it an ideal place for milking cows. Their coexistence with dairy cows led them to be great herdsmen, and they developed some of the best dairy cattle in the world. The most notable dairy breed, the black and white Holstein cow, originated in the Netherlands. They also invented many types of cheese, including Gouda and Edam. In fact, their great affinity for milk and dairy products has made them one of the tallest nationalities in the world. Dairy is at the very foundations of that country.

Dairy in my DNA

It is interesting to know our family history, but records can only go back so far. We DNA test our cows, so I thought, “Why aren’t we DNA testing ourselves?” 23andMe is a DNA test that you can do to trace your roots. The test allows you to trace which part of the world your DNA originates. It also allows you to trace your X or Y chromosome from your mother and father. Researchers can trace back your family’s roots based on certain mutations that happened over time. The details of your chromosomes show a trail and you can learn more about your genetic ancestors.


The test was interesting because it revealed that dairy farming was more than a family hobby; my ancestors shared a real passion for cows. The test showed that my Y chromosome was part of the R1b haplogroup. Researchers speculate that the R1b haplogroup was one of the first populations responsible for domesticating cattle in northern Mesopotamia some 10,500 years ago.

Back then cattle were called aurochs. These were wild cattle like the buffalo in North America, and the people are thought to have lived alongside wild herds. Domestication of the aurochs began in the southern Caucasus and northern Mesopotamia from about the sixth millennium BC. Domestication came from only 80 cows. The aurochs would have been challenging to domesticate because they were unruly and much larger than the cows of today. Julius Caesar commented in his day that they were almost as large as elephants. It is speculated that the wild auroch reached 3,300 pounds.

“These are a little below the elephant in size. … But not even when taken very young can they be rendered familiar to men and tamed.” –Julius Caesar

It is thought that R1b tribes managed to domesticate auroch herds in northern Mesopotamia 12,000 years ago to secure a more stable food source. They had to have been great herdsmen. Earliest evidence of cattle domestication dates from 8500 BC and is found in the Pre-Pottery Neolithic cultures in the Taurus Mountains of Turkey. This area of northern Mesopotamia is presumably the area from which R1b lineages started expanding and is the "original homeland" of R1b (the birthplace of cattle culture).

The migratory spread of dairy culture

The migration from northern Mesopotamia of these herding R1b people can be followed archeologically through the presence of domesticated cattle, milk residues in pottery and even temple walls. Cattle culture and the R1b Y chromosome mutated and branched in three different factions from the original homeland – one stayed in Anatolia; one branched south to Egypt and North Africa (R1b-V88); and the other crossed the Caucasus Mountains to greener pastures towards Europe (R1b-269). These people spread dairy culture throughout the world. Remnants of dairy culture litter these migratory paths.

Obviously though, my Y chromosome could be traced back to the R1b-269 group, which migrated to Europe. Interestingly these people supplanted local populations, probably because of the many advantages cattle culture yielded, but these other cultures took note because dairy culture spread from those early cattlemen to those cultures around them. The Proto-Italo-Celto-Germanic R1b people had reached what is now Germany by 2500 BC. And those first R1b Indo-Europeans reached France and the Low Countries by 2200 BC. Today, the R1b Y chromosome is the most common haplogroup in western Europe. The countries with the highest R1b Y-chromosome concentrations are still some of the strongest consumers of milk and dairy products. The very trail that researchers have discovered of dairy farming’s spread to Europe is the very same path as my genetic DNA.

And so while I thought my love of dairy was because of being raised on a farm, it was inspiring to learn that things run deeper. I am not alone in my life’s journey. Not only am I following the same path as my dad and grandpa, but I’m walking the same path of those other men in our family’s history – sharing those same simple, unexplainable joys of working and coexisting with cows. And it’s a passion written in my DNA.  end mark

Stephen Weststeyn is a California dairy farmer. Read his blog, Dairy Moos.

PHOTO: California dairy farmer Stephen Weststeyn recently took a DNA test to learn more about his dairy roots. Photo provided by Stephen Weststeyn.