Goats and Cattle FM - Freemartinism in cattle

Freemartinism is one of the most severe forms of sexual abnormality among cattle. It concerns a vast majority (over 90%) of females originating from heterosexual twins. The male co-twin to freemartinism is usually fertile and normally developed.

Freemartinism cannot be prevented. It occurs when a female twin shares the uterus with a male twin. The placental fluids are exchanged between the two fetuses. The antigens and hormones responsible for carrying the unique sex characteristics of each calf are mixed. The reproductive organs of the male fetus develop earlier than those of a female fetus. Thereby, the female's genitalia are affected. The female's reproductive tract is severely underdeveloped. Often the ovaries are underdeveloped and are not capable of producing eggs. The reproductive tract does not supply sufficient hormones necessary to maintain a pregnancy. Although, the female's external genitalia appear normal very often.

A female twin born with a male twin has no reproductive value, it is important not to spend time and money preparing the heifer to go into your breeding herd.

Finally, if calf twins - male and female - are born, let examine female's blood. The test is based on searching male's genemarkers in female's body. Its early diagnosis is recommended to avoid economic losses caused by useless therapeutical treatment.

References:
Nowacka J, Switonski M, Mackowski M, Slota E, Radko A, Zabek T, Urbaniak K: The ambiguity of freemartinism diagnosis in cattle revealed by cytogenetic and molecular techniques; Czech J. Anim. Sci., 49, 2004 (6): 239-243
Alberta Ag-Info Centre - http://www1.agric.gov.ab.ca/$department/deptdocs.nsf/all/faq8285