What is a Freemartin?
Most folks know that a freemartin is a heifer, born twin to a bull and, as a result of the two fetuses sharing a common blood supply, the heifer is abnormally developed sexually. “We generally find about 90 percent of those heifers to be sterile,” said Eldon Cole, Extension Livestock Specialist, University of Missouri. Veterinarians say this is not uncommon to find a heifer that’s a freemartin.
The owner sometimes will check his records and say, “Yes, there was a twin bull with her.” Sometimes they’ll say, “No, she was a single.” Well, apparently, the single heifer did have a brother early in gestation that affected her sexual development.
The next question is usually, “Why do they call them freemartins?” said Cole. “I’d never heard an explanation until I read one in a magazine recently.”
“The story is that in the mid-1600s, European farmers would donate the sterile heifers to the annual Saint Martin celebration. Because the heifers’ value was minimal, the ‘free’ heifers became known as ‘freemartins.’”
[This is a sidebar accompanying the Twins story]