Minimizing farrowing difficulties and increasing the number of pigs born and weaned from a sow is every pork producer’s goal.

Consequently, oxytocin, which occurs naturally in gilts and sows, is commonly used to ease the farrowing process. It helps promote uterine contractions as well as milk release. “But, when it´s administered too soon, oxytocin can increase the number of stillbirths, says Mike Tokach, Kansas State University swine specialist.

A National Animal Health Monitoring System study showed that more than 8 percent of pork producers administer oxytocin to all farrowing sows/gilts. “There is a tendency to overuse oxytocin because producers think it will speed up the farrowing process,” notes Tokach. In reality, it causes the sow to have contractions before piglets are ready to be born. “This can cause ruptured umbilical cords, which results in oxygen deprivation,” he adds.

The recommended dosage is 1/2 cc, with no more than two doses per sow. It should not be used until after half of the litter is born (the 6th piglet)— plus an extra 40 minutes. “The average interval between piglets born is 30 minutes. Therefore, a 40-minute gap is a sign that the sow may be fatigued,” says Tokach. Gilts should not receive an oxytocin injection because they are not likely to become fatigued. “This doesn´t mean that gilts won´t have farrowing problems,” he adds. “But, farrowing problems in gilts are usually due to piglets blocking the birth canal, not because of inadequate uterine contractions. Increasing contractions with a lack of space applies added pressure on piglets, which is how umbilical cords become ruptured and cause oxygen deprivation.”

Studies show that 75 percent of stillbirths occurred after the 8th piglet was born in sows that did not receive oxytocin. For sows that receive a single dose, stillbirths increased, with 88 percent occurring before the 5th piglet.

Tokach offers these recommendations for oxytocin use:

  • Administer oxytocin only after the sow’s cervix is fully dilated.
  • Limit use with gilt farrowings.
  • For a sow farrowing normally, do not use oxytocin until a least six piglets have been born.
  • Use oxytocin when the birth interval between piglets is more than 40 minutes.
  • Use a maximum of two doses per farrowing sow.