Induced parturition in cattle. 1. Clinical studies

Area of Science:

• Veterinary Medicine
• Reproductive Endocrinology
• Bovine Reproduction

Background:

• Dystocia, or difficult birth, is a significant concern in livestock, potentially leading to complications for both dam and offspring.
• Hormonal induction of parturition is explored as a method to manage calving and reduce dystocia incidence in cattle.
• Corticosteroids, such as dexamethasone, are known to mimic natural hormonal changes preceding parturition.

Purpose of the Study:

• To investigate the efficacy of dexamethasone for inducing parturition in Friesland heifers.
• To assess the impact of induced parturition on calving ease and subsequent reproductive performance.
• To evaluate the incidence of complications, specifically retained placenta, following dexamethasone administration.

Main Methods:

• Seventeen Friesland heifers were administered 39 mg of dexamethasone intramuscularly on day 267 of gestation.
• Animals were monitored for signs of parturition, and the time to fetal membrane expulsion was recorded.
• Post-calving assessments included monitoring for retained placenta and pregnancy status via rectal examination 5-7 months later.

Main Results:

• Parturition occurred on average 57 hours post-dexamethasone administration.
• Assisted calving was required in three heifers, with one needing a second dexamethasone injection.
• A high incidence of retained placenta (68.8%) was observed; 76.5% of heifers became pregnant again.

Conclusions:

• Dexamethasone can effectively induce parturition in heifers, but it is associated with a high rate of retained placenta.
• Assisted calving appears linked to non-pregnancy outcomes.
• While subsequent fertility is largely maintained, the high complication rate necessitates careful consideration of this induction method.