Use of a Vaginally Administered Gel Containing the GnRH Agonist Triptorelin and a Single, Fixed-Time Artificial Insemination in Pigs under Commercial Conditions: Productive and Economic Impacts

Fixed-time artificial insemination is an important technique in swine production that can improve reproductive efficiency and meat production quality through making better use of the genetic potential of breeding males and reducing the costs associated with double or multiple inseminations. Our goal was to evaluate the vaginal application of the GnRH agonist triptorelin acetate to synchronize ovulation in post-weaning sows and facilitate the implementation of a single, fixed-time insemination. In the first experiment, the efficacy of treatment with triptorelin in animals with or without signs of estrus was analyzed using a single insemination at a fixed time, compared to a control group following the standard insemination strategy. The farrowing rate was comparable between the triptorelin and control groups (100 vs. 87.50%), but triptorelin treatment without estrus had a lower rate (50%). Litter size did not differ between the groups. Estradiol and progesterone levels at 96 and 120 h post-weaning were similar in the control and triptorelin groups (<i>p</i> > 0.05). These results suggest that triptorelin has the potential to synchronize ovulation in pigs without affecting post-weaning hormonal profiles. In a second experiment, the objective was to evaluate the productive and economic impact of implementing a treatment with triptorelin acetate 96 h after weaning, compared to the standard insemination protocol. Sows were grouped according to treatment (control vs. triptorelin) and estrus onset (≤5 days and >5 days after weaning, which was considered late estrus). The farrowing rate was lower in the late-estrus control group than in the control and triptorelin groups, and similar to that in the late-estrus triptorelin group. No differences were found in litter size and live or dead piglets born (<i>p</i> > 0.05). We developed an estimation model to assess the cost/benefit of intravaginal triptorelin administration at 96 h post-weaning. The overall result was that the use of triptorelin increased the financial benefit per inseminated sow by EUR 15-20. This improvement was mainly related to an increase in the reproductive performance of the treated sows compared to the control sows and the reduction in the number of inseminations per sow. These results highlight the potential of triptorelin to optimize reproductive management in pigs, improving efficiency and economic viability.