Birth of piglets after deep intrauterine insemination with flow cytometrically sorted boar spermatozoa

The present study was carried out to determine the pregnancy rates, farrowing rates and litter size in sows with either induced or spontaneous ovulation inseminated with flow cytometric sorted spermatozoa using deep intrauterine insemination technology. Spermatozoa were stained with Hoechst 33342 and sorted by flow cytometry/cell sorting but not separated into separate X and Y populations. In Experiment 1, sows (n=200) were weaned and treated for estrus/ovulation induction with eCG/hCG. Inseminations with either sorted (70 or 140 million) or non-sorted (70 or 140 million) spermatozoa were done using a specially designed flexible catheter. Farrowing rates were 39.1 and 78.7% for 70 million of sorted and non-sorted, respectively, and 46.6 and 85.7% for 140 million of sorted and non-sorted, respectively (P<0.05). The litter size in sows inseminated with sorted spermatozoa showed a tendency to be lower than when non-sorted spermatozoa were inseminated. In Experiment 2, sows (n=140) were inseminated as in Experiment 1 except that natural estrus was used. The ovaries of these sows were evaluated by transrectal ultrasonography. Farrowing rates were 25 and 77.2% for 70 million of sorted and non-sorted, respectively, and 32 and 80.9% for 140 million of sorted and non-sorted, respectively (P<0.05). These results show that the Deep Intrauterine Insemination technology can be successfully used to produce piglets from sorted spermatozoa when sows are hormonally treated to induce synchronous post weaning oestrus and ovulation.