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Delaying Post-Weaning Estrus Expression in Sows through Chorionic Gonadotropin Administration

Strategic Insights

— 1 min read

Researchers in Brazil have investigated the effectiveness of administering chorionic gonadotropin (eCG and hCG) during lactation to delay post-weaning estrus expression in sows. The study, led by Monike Willemin Quirino, involved 62 sows that were divided into three treatment groups: a control group receiving saline administration, a 500 IU group receiving eCG and hCG, and a 1000 IU group receiving eCG and hCG. The results showed that the administration of 500 or 1000 IU of eCG and hCG during lactation effectively inhibited estrus expression in 76 to 90% of treated sows, sustaining high serum P4 levels for at least 13 days post-weaning.

Key Takeaways:

  • The study evaluated the efficiency of two different dosages (500 IU and 1000 IU) of eCG and hCG administered during lactation to delay post-weaning estrus expression in sows.
  • Sixty-two sows were selected and allocated to one of three treatments: Control (n = 20), 500 IU (n = 21), or 1000 IU (n = 21).
  • Estrus detection was performed twice daily after weaning, and blood samples were collected on D-7, D-1, D+6, and D+13.
  • The percentage of sows detected in estrus post-weaning was greater in the Control group (90.0%) compared to the 500 IU (23.8%) and 1000 IU (9.5%) groups.
  • Administration of 500 or 1000 IU of eCG and hCG during lactation effectively induced the formation of corpora lutea and sustained high serum P4 levels for at least 13 d post-weaning.
  • The study showed that the treatment could inhibit estrus expression in 76 to 90% of treated sows.

Statistics:

  • 62 sows were selected and allocated to one of three treatments: Control (n = 20), 500 IU (n = 21), or 1000 IU (n = 21).
  • 90.0% of sows in the Control group were detected in estrus post-weaning.
  • 23.8% of sows in the 500 IU group were detected in estrus post-weaning.
  • 9.5% of sows in the 1000 IU group were detected in estrus post-weaning.

Sources:

  • "Treatment with chorionic gonadotropins during lactation inhibits post-weaning estrus expression in sows." Domestic Animal Endocrinology, 2025;94:106977.
  • Monike Willemin Quirino, Mestrado e Doutorado Profissional em Producao e Sanidade Animal (PGPSA) - Instituto Federal Catarinense, Araquari, SC, Brazil.
  • Elsevier Science Inc, Ste 800, 230 Park Ave, New York, NY 10169, USA. (www.elsevier.com; www.journals.elsevier.com/domestic-animal-endocrinology/).

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