Post-cervical artificial insemination with a low sperm dose in gilts and sows improved reproductive performance in subtropical climates

The use of post-cervical artificial insemination (PCAI) and corresponding sperm dose in gilts is still inconclusive. The present study evaluated the effects of cervical artificial insemination (CAI) and post-cervical artificial insemination (PCAI) using three semen doses (3 × 109 sperm/75 mL, 2 × 109 sperm/50 mL, and 1 × 109 sperm/25 mL) on reproductive performance, procedure efficiency, and adverse events in gilts and sows under subtropical climatic conditions. A total of 716 female Hampshire and Ghungroo crossbred (50%) pigs (284 gilts and 432 sows) were allocated to a 2 × 3 factorial experimental design with AI technique (CAI vs. PCAI) and semen dose as fixed factors. The interaction effect between AI techniques and semen doses on reproductive variables was also analysed. In gilts and sows, non-return and farrowing rates were significantly higher in PCAI than CAI at all semen doses. Similarly, total piglets born, piglets born alive, and litter size at weaning in gilts and sows were significantly influenced by AI technique, semen dose, and their interaction, with PCAI outperforming CAI at lower doses. However, PCAI catheter passage in gilts and sows required significantly more attempts than CAI. PCAI significantly reduced the time to infuse semen doses and total procedure time across doses in sows. Semen backflow was significantly lower in gilts and sows inseminated by PCAI. Our data suggest that, under conditions of successful catheterization (per-protocol), PCAI at lower semen doses was associated with improved reproductive performance in gilts and sows, reduced semen loss, and enhanced procedural efficiency compared to cervical AI; however, these findings may vary with catheterization success.