INDUCED INFERTILITY IN CATTLE BY ISO-IMMUNIZATION WITH SEMEN AND TESTIS

Abstract

Iso-immunization of heifers with bull semen and homogenized testis combined with Freund''s complete adjuvant resulted in an induced temporary infertility. Eleven heifers injected intradermally with semen and 6 heifers with testis required an average of 4.11 and 4.83 inseminations/conception, respectively, compared with 9 control heifers which averaged 1.11 services/conception. Two heifers immunized with semen were slaughtered after 8 and 12 unsuccessful inseminations, and an unfertilized ovum was recovered from each animal. Intra-uterine injection of semen and adjuvant caused 9 heifers to require an average of 2.67 services/conception compared with an average of 1.0 for 4 control animals that had received intra-uterine injections of adjuvant and saline or adjuvant and rabbit semen. Four diagnosed pregnancies of the iso-immunized heifers underwent degeneration and an additional 7 incidences of embryo loss were suspected from delays in return to estrus after breeding. There was no evidence of embryo mortality in the control animals. Specific sperm agglutinins were detected in the serum and uterine and vaginal secretions of the iso-immunized heifers. The fertility of a particular insemination appears to have been negatively associated with the serum titer of sperm agglutinins at the time.