MANHATTAN, Kan. – A main concern of swine producers is how they can minimize dystocia, or birthing difficulty, and increase the number of piglets born and weaned from a sow.
Dystocia can result in an increase in stillbirths, or piglets that are normally developed, but are born dead or die shortly after birth, said Mike Tokach, swine scientist for Kansas State University Research and Extension.
An increase in stillbirths decreases the number of piglets weaned from a sow.
Hormones. To help ease the birth process and reduce the number of stillbirths, many swine producers administer a hormone called oxytocin, which occurs naturally in gilts and sows.
A gilt is a female that is having her first litter of piglets and a sow is one that has had two or more litters.
“Oxytocin is responsible for a sow’s letdown and release of milk and for uterine contractions, which help in the farrowing process,” Tokach said.
“But, when it’s administered too soon, oxytocin can increase the number of stillbirths. Gilts should not receive an oxytocin injection because they are not likely to become fatigued.”
Tendencies. A 1995 National Animal Health Monitoring System study shows that more than 8 percent of swine producers administer oxytocin to all farrowing sows.
“There is a tendency to overuse oxytocin because producers think it will speed up the farrowing process,” Tokach said.
“But, really, it’s causing the sow to have contractions before piglets are ready [to be born]. This causes ruptured umbilical cords, which results in oxygen deprivation.”
Dosage. The recommended dosage is a half cc with a maximum of two doses per sow and should not be injected until after approximately half of the litter is born (the sixth piglet), plus an extra 40 minutes.
“The average time interval between piglets born is 30 minutes, therefore, if another piglet hasn’t been born within 40 minutes, then this is a sign that the sow may be fatigued,” Tokach said.
“This is when oxytocin can be used to aid the farrowing process.”
“This doesn’t mean that gilts won’t have farrowing problems, though,” he said.
Problems. “But, farrowing problems in gilts are usually due to piglets blocking the birth canal due to a lack of space and not because of inadequate uterine contractions. Increasing contractions with a lack of space applies added pressure on piglets and this is how umbilical cords become ruptured and cause oxygen deprivation.”
Recent studies show that 75 percent of stillbirths occurred after the eighth piglet was born in sows that were not administered oxytocin.
In sows that were given a single dose of oxytocin, the percentage of stillbirths increased with 88 percent occurring before the fifth piglet was born.
* * *
* Administer oxytocin only after the cervix is fully dilated.
* Limit usage in gilt litters.
* For a normally farrowing sow, do not use oxytocin until a minimum of six piglets have been born.
* Use oxytocin when a sow has not had a piglet for more than 40 minutes.
* Only use a maximum of two doses per sow per farrowing.