In this freemartin case report the authors present the clinical and morphological findings of a freemartin ewe with an abnormal position of two lymph nodes. Freemartins can have varying degrees of phenotypic masculinization, including, in some cases, having active male gonads and exhibiting male behaviors such as heat detection and aggressiveness. During the clinical examination of the freemartin ewe, a morphological abnormality of the vulva, the presence of scrotal sacs, and a lack of mammary tissue development were noted. On inspection of the vaginal channel, an extremely enlarged clitoris, resembling a penis, was found. The clinical evidence suggested freemartinism.
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Freemartinism is defined as a sterile female bovine calf born twin to a male. Freemartinism traces its origin to what happens in the womb. Specifically, it begins with the blood supply from the carrying dam to the two placental sacs of male and female calves.
The extent of malformation of the reproductive system will depend on when the blood transfer occurred, and at which stage of neo-natal development.
Research shows that one in 13 female calves born twin to a male are, in fact, normal and can reproduce. A female born twin to a male will not be registered until she is confirmed a breeder.
The freemartin test is a predictive test and is not an absolute indicator of the reproductive ability of an animal. While the test may be used as a management tool, the result of the test is no longer accepted for registration. A test kit and corresponding directions will be provided. The test is not intended or suficient to definitively detect freemartinism or determine sterility. The original date stamped submission date will be used to calculate the fees. Search For Animal. About Us About Us Governance.
Holstein Canada Services Freemartin Freemartin. What Is It? How does Holstein Canada deal with it? Is a test available?
Abnormal position of lymph nodes in a freemartin sheep
A freemartin or free-martin sometimes martin heifer is an infertile female mammal with masculinized behavior and non-functioning ovaries. The animal originates as a female XX , but acquires the male XY component in utero by exchange of some cellular material from a male twin, via vascular connections between placentas: an example of microchimerism. Freemartins are known to have been described by the Roman writer Varro , who called them "taura". The 18th-century physician John Hunter discovered that a freemartin always has a male twin. It was hypothesized early in the 20th century that masculinizing factors travel from the male twin to the female twin through the vascular connections of the placenta because of the vascular fusion, and thereby affect the internal anatomy of the female. Several researchers made the discovery that a freemartin results when a female fetus has its chorion fuse in the uterus with that of a male twin.
[Freemartinism in cattle]