Tag Archives: freemartinism

Norman Part III: Our bull calf and his freemartin twin sister

Mama Trudy and Norman

Mama Trudy and baby Norman

Recently I’ve written about a set of twins born at our ranch. The mother cow unfortunately promptly rejected the bull calf in favor of the heifer calf such that Trudy and I soon became surrogate parents to the bull calf. We have been bottle feeding him twice a day. Well at least we don’t have to throw him over our shoulders and burp him!

While cattle twins are rare, We’ve learned the concept of freemartinism in cattle. This occurs when a male calf (Norman in our case) and his female twin are born. The heifer usually has an abnormal reproductive tract. Her abnormality occurs due to the presence of male hormones in the bloodstream in utero that prevents normal development of the ovaries and/or other aspects of her reproductive tract.

The freemartin becomes an infertile cow with masculinized behavior (someone else will have to share exactly what this behavior looks like as I haven’t noticed any unusual spitting or scratching (thank you Ann Richards for the quote). A freemartin occasionally occurs in sheep, goats, and pigs.

The Roman writer Varro described freemartins and referred to them as “taura”. John Hunter, an 18th century physician, determined a freemartin always has a male twin. Talk about creating sibling grudges!

The question arises whether this condition might occur in human twins as this has been claimed in folklore. This belief was perpetuated for generations and was mentioned in the early writings of Bede. No good support exist for freemartins in human twins to the best of my knowledge. If others know differently please share your thoughts and level of support for this.

Norman and a big friend

Norman and a big friend


Am pleased to share with you that Norman is growing and appears healthy. Another mama cow has allowed Norman periodically to nurse. Likewise his sister does well and continues to enjoy the mothering offered her by her biological mother. As for Norman he spends time in the nursery with the other calves during the day, scampers toward Trudy and me when we approach him, and like his ears and neck scratched.

Norman’s twin (the freemartin) is destined to become a beef calf rather than for breeding purposes. If I don’t watch it, Norman may, if Trudy has her way, end up as a big backyard pet.

Seeing Double

Several weeks ago one of our mama cow gave birth to a set of twins. I performed the classic double-take, thinking I must be seeing double. The two newborn calves were distinct from one another with a bull calf having a white face and otherwise light brown color and the other being a gray heifer.

Somewhere I’d read beef cattle reject one twin more often than do milk cows because beef cows produce less milk than do milk cows. In any event, rejection was the case with us. It didn’t take long to determine mama paid little attention to her bull calf and was downright mean to him when he tried to suckle.

On viewing this, I immediately took off to the feed store to purchase colostrom and a large bag of powered cow’s milk. The next challenge was to separate the bull calf from his mother in order to feed him. While the cow in question was not a good mother, she still had protective instincts for her bull calf as well as for her heifer calf. She tried to run me down several times when I approached, brandishing a bottle of milk. Having twice before during an earlier calving having been run down and rolled by this unpleasant mama, I was surely on my guard.

The frequency of twinning in beef cattle is about half a percent, that is one in every 200 births. We have never before encountered this on our ranch. The twin calves are usually smaller than single births and have a higher rate of birthing complications. Just imagine eight legs and two heads trying to exist the uterus. This gives rise to all sorts of possible complications and explains the increased rate of dystocias.

While unfamiliar with twins, Trudy and I have previously had to bottle feed several other calves. This proves time consuming (feeding twice a day) but gratifying. It is fun to see the bottle calf emerge running from the herd in the direction of a bottle toting person.

Follow on articles will touch on the naming of the calf and the phenomenon of freemartinism that frequently occurs with one bull calf and one heifer calf. More to come.