R300 Freemartinism

R300 Categories: ,

 39,95 ex. VAT
 48,34 inc. VAT

Breed:  All Breeds
Sample material:  Blood EDTA, Blood Heparin


working days

For inquiries about our products or requests for larger volumes of DNA tests, please contact us.
Back to all DNA tests for cattle

Freemartinism, also known as XX/XY Chimerism, is a form of intersex that occurs in cattle, resulting in a sterile, masculine heifer (freemartin or martin heifer). The phenomenon is caused by blood exchange between twin foetuses, a common occurrence in cattle pregnancies. In the case of a male-female set of twins, cells from the male with an XY genotype end up in the female’s (XX) system. This exposes the female to male developmental hormones, resulting in sterility and potentially abnormal genitalia and other sex characteristics.

Approximately 90% of male-female twin calves result in a freemartin. Since freemartinism is not always apparent on physical examination of the calf, a genetic test can be useful to identify them.


Gene: XX/XY chimerism

Organ: Multiple systems


Year published: 2006

Clinical Features

Freemartins are sterile and have both XX and XY chromosomes. The anatomical signs are not always apparent, but can include a shortened vagina and a lengthened tuft of hair on the vulva, and even a scrotal sac. Freemartins behave and develop similarly to oxen.


Omia: 393

Pubmed: 17037616