US dairy exporters keep finding new markets for cheese and dairy ingredients despite facing trade tensions.
There are over nine million dairy cows in the US, and the vast majority of them are Holsteins, large bovines with distinctive black-and-white (sometimes red-and-white) markings.
The amount of milk they produce is astonishing. So is their lineage. Media reports says when researchers at the Pennsylvania State University looked closely at the male lines a few years ago, they discovered more than 99% of them can be traced back to one of two bulls, both born in the 1960s.
That means among all the male Holsteins in the country, there are just two Y chromosomes.