Trial 3. Abortigenicity and passage through the placenta 22 cows remain well until the end of pregnancy giving birth to 23 healthy calves (there was a case of twins). The 2 cases of abortion were thoroughly investigated. There were no evidences of IBR infection in these abortions: no virus was detected in placenta or foetus by a number of technics, including immunohistochemistry. In contrast, a bacterial infection was determined in one of the abortions. All calves born to term were in good health and were completely seronegative to IBR antibodies before sucking the colostrum.
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a·bor·ti·gen·ic (ə-bôr′tə-jĕn′ĭk)
adj.Abortifacient.

a·bor·ti·fa·cient (ă-bōr-ti-fā'shent), Avoid the misspelling abortefacient.
1. Producing abortion. Synonym(s): aborticide, abortient, abortigenic, abortive (3)
2. An agent that produces abortion.
[L. abortus, abortion, + facio, to make]
http://medical-dictionary.thefreedictionary.com/abortigenic