A freemartin or free-martin (sometimes martin heifer) is an infertile female mammal with Freemartinism is the normal outcome of mixed-sex twins in all cattle species that have been studied, and it also occurs occasionally in other mammals. J Am Vet Med Assoc. May 15;(10) Diagnosis of freemartinism in cattle: the need for clinical and cytogenic evaluation. Zhang T(1), Buoen LC. Freemartinism is recognized as one of the most severe forms of sexual abnormality among cattle. This condition causes infertility in the female.

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If both fetuses are the same sex this is of no significance, but if they are different, male hormones pass from the male twin to the female twin.

A total of blood samples from female calves born co-twin to male calves were examined cytogenetically for freemartinism between and Also, many but not allfreemartins have a shortened vagina compared with that catyle a fertile heifer.

The uterus is also underdeveloped, and the reproductive tract does not supply sufficient hormones necessary to maintain a pregnancy. Six hundred calves How does this occur?

We propose that obvious freemartins be identified by use of the vaginal-length test and that the remaining clinically questionable calves be differentiated cytogenetically. Tandler and Keller vs. General and Comparative Endocrinology.

In most cattle twins, the blood vessels in the chorions become interconnected, creating a shared circulation for both twins. Bovine health Twin Sex. If suspected, a test can be done to detect the presence of the male Y-chromosomes in some circulating white blood cells of the subject.

An introduction to behavioral endocrinology. What are the economic implications? Freemartinism is one of the most severe forms of sexual abnormality among cattle. When these antigens mix, they affect each other in a way that causes each to develop with some characteristics of the other sex.


It does not normally occur fattle most other mammals, though it has been recorded in sheep[13] goats[14] pigs[15] deer, and camels. In some cases, there are no symptoms of freemartinism because the male twin may have been aborted at an earlier stage of gestation.

By using this site, you agree to the Terms of Use and Privacy Policy. Lillie and the question of priority”. The ovaries of the freemartin do not develop correctly, and they remain very small.

Male-derived cells and their progeny can be easily visualized in the freemartin tissues, as only they contain the male Y chromosome. This combination of procedures could prevent unnecessary economic losses and preserve important genetic material.

Freemartinism cannot be prevented. Philosophical Transactions of the Royal Society of London. Testicle size is associated with fertility, so there may be freeamrtinism reduction in bull fertility. Reduced fertility sometimes occurs in the male twin, but in ninety percent of the cases the fgeemartinism twin is completely infertile.

Journal of Agricultural Research. A freemartin is the normal outcome of mixed twins in all cattle species which have been studied. The placental membranes connect the fetus to the dam are shared, and the placental fluids are exchanged between the two fetuses.

Therefore, probably a large number of female co-twins that are freemartknism truly freemartins are sold to slaughter every year. Can freemartinism be prevented? The result was published in by Tandler and Keller. Lilliewho published it in Science in It is not a genetic trait that is passed on through generations; it occurs randomly from the conception of two embryos instead of one.


Detection and diagnosis of a freemartin is critical from an economic standpoint.


About About 5m Publishing Our Editors. Often the ovaries are underdeveloped and are not capable of producing eggs. Freemartins are occasionally used in stem cell and immunology research. Although the male twin in this case is only affected by reduced fertility, in over ninety percent of the cases, the female twin is completely infertile.

This condition causes kn in the female cattle born twin to a male.

Freemartinism in Cattle – Frequently Asked Questions

Retrieved from ” https: This page was last edited on 23 Octoberat Freemartinism cannot be prevented; however, it can be diagnosed in a number of ways ranging from simple examination of the placental membranes freemartinism chromosomal evaluation.

The presence of male hormones impairs the development of the female reproductive system. The 18th-century physician John Hunter discovered that a freemartin always has a male twin. This transfer of hormones and antigens causes the female’s reproductive tract to be severely underdeveloped, and in some cases they express characteristics of a male reproductive system. However, the reproductive organs of the male fetus develop earlier than those of a female fetus, which results in the female genitalia being affected.

Freemartins behave and grow in cattl similar way to castrated male cattle steers. Because of a transfer of hormones or a transfer of cells, the heifer’s reproductive tract is severely underdeveloped and sometimes even contains some elements of a bull’s reproductive tract.