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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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This information published to the web on March 19, Detection and diagnosis of a freemartin is critical from an economic standpoint. Reduced fertility sometimes occurs in the male twin, but in ninety percent of the cases the female twin is completely infertile. Cytogenetic evaluation for freemartinism thus offers the added value of simultaneous surveillance for cytogenetic aberrations in male and female cells of a sample.

The cattleman can predict the reproductive value of this heifer calf at birth and save the feed and development costs if he is aware of the high probability of freemartinism.

The animal originates as a female XXbut acquires the male XY component in utero by exchange of some cellular material from a male twin, via vascular connections between placentas: Freemartinism is one of the most severe forms of sexual abnormality among cattle.

Image Reprinted from http: Freemartinism occurs when a female twin shares the uterus with a male. All pages needing factual verification Wikipedia articles needing factual verification from May It does not normally occur in most other mammals, though it has been recorded in sheep[13] goats[14] pigs[15] deer, and camels.

Most often the external genitalia of the female appears normal, but the internal organs are underdeveloped. This page was last edited on 23 Octoberat Can freemartinism be seen externally? Freemartinism is recognized as one of the most severe forms of sexual abnormality among cattle.


Diagnosis of freemartinism in cattle: the need for clinical and cytogenic evaluation.

Freemartiism About 5m Publishing Our Editors. Lilliewho published it in Science in Journal of Dairy Science. Is the male twin affected at all by this condition? A total of blood samples from female calves born co-twin to male calves were examined cytogenetically for freemartinism between and Freemartins are occasionally used in stem cell and immunology research. The twins develop with some sex characteristics of both the male and female.

Events Latest Events Submit Event. Registration VAT No. In some cases, there are no symptoms of freemartinism because the male twin may have been aborted at an earlier un of gestation.

What Is A Freemartin – The Cattle Site

Retrieved from ” https: Also, the ovaries of a freemartin do not produce the hormones necessary to induce the behavioral signs of heat. 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 freemartinksm. This causes exchange of blood and antigens carrying characteristics that are unique to each heifers and bulls.

Estimates of the percentage of natural beef cattle births that produce twins vary.

Freemartinism in Cattle – Frequently Asked Questions

We propose that obvious freemartins be identified by use of the vaginal-length test and that the remaining clinically questionable calves be differentiated cytogenetically. The exchange of fluid and blood between the two calves mixes the antigens responsible for carrying the unique sex characteristics of each calf.

Thus, by analyzing these tissues, one can investigate the capacity of hematopoietic stem cells or other circulating cells to produce other tissues in addition to blood.


For example the vulva may be normal, but there may be large amounts of hair present or the udder will not be fully developed and sometimes it is not noticeable at first glance. Lillie and the question of priority”.

What are the economic implications? Tandler and Keller vs. Freemartinism frefmartinism be prevented. Usually, the vulva is normal except that in some animals an enlarged clitoris and large tufts of vulvar hair exist. Philosophical Transactions of the Royal Society of London. Approximately one-half of the sets of twins should contain both a bull and a heifer calf.

The placental membranes connect the fetus to the dam are shared, and the placental fluids are exchanged between the two fetuses. In some cases, the female genitalia may appear to be male. Male-derived cells and their progeny can be easily visualized in the freemartin tissues, as only they contain the male Y chromosome.

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A freemartin is genetically female, but has many characteristics of a male. Genetic testing for the Y-chromosome can be performed within days of birth and can aid in the early identification of a sterile female bovine. The freemartin model allows one to analyze perfectly healthy and unmanipulated animals, without resorting to transplantation often used in stem cell research. 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.

Freemartins are known to have been described by the Roman writer Varrowho called them “taura”.