Abstract

In the first experiment, copulations in 10 domestic ferrets were interrupted 5 minutes after penetration. Ten control females were bred without interruption to the same males. Both control and experimental animals were rebred in the same manner to the same males 24 hours later. Sperm were present in all postcoital washes. We allowed all females from the first experiment to proceed to their expected date of parturition. All females who had been interrupted during copulation failed to conceive, whereas all controls produced litters. In a second experiment, the same procedure was followed; however, in this experiment, ferret oviducts and uteri were flushed 10 days after copulation. Nine control females (one failed to ovulate) averaged 5.2 blastocysts (range 2-10; S.D. = 5.8) per animal. Of nine interrupted copulation ferrets (one failed to ovulate), only one animal produced a single blastocyst. The interrupted copulation group averaged 4.4 unfertilized eggs (range 2-10; S.D. = 5.0) per female. Although ferrets ovulated during short copulations, those eggs are not likely to be fertilized.