FERTILIZATION RATE IN SHEEP UNILATERALLY INSEMINATED WITH FROZEN-SEMEN

In order to evaluate a simple surgical technique for artificial insemi nation (AI) with frozen semen, 40 adult ewes were synchronised with va ginal sponges impregnated with 60 mg of medroxyprogesterone acetate fo r 12 d and a single injection of 400 IU PMSG at sponge withdrawal. Sem en from fertile rams was pooled and frozen in straws, each containing 3 x 10(8) spermatozoa. All ewes were inseminated 60 h after PMSG injec tion. Twenty ewes (group A) were unilaterally inseminated by a small m idventral laparotomy and 20 (group B) were cervically inseminated. Fer tilization rate was measured by flushing of uteri and oviducts through out a laparotomy carried out 3-4 d after insemination. The 83.7% ferti lization rate in group A was significantly different (P < 0.0001) than the 19.1% fertilization rate of group B. This surgical technique seem s to be useful when no laparoscopic equipment is available.