Despite advances in genetics, health, nutrition and management, U.S. pig farmers are losing more than 10% of their pigs before they even hit the ground, says Andrew Bents, swine technical veterinarian at Hubbard Feeds.
“We work so hard in the breeding barn to provide a good environment, nutritious feed, optimal boar exposure and a comfortable living space for the sow, and we want to be rewarded with the fruits of that labor as we walk the farrowing rooms by seeing big litters of pigs competing for their mothers’ milk,” Bents says.
In 2019, the average number of pigs born in total per litter was 14.88 pigs per sow, PigChamp reports; however, of those pigs, an average of 1.13 per litter were stillborn and 0.38 per litter were mummified.
Tim Safranksi, University of Missouri Extension state swine specialist, says in order to reduce the number of stillborns, it’s important to fully understand what a stillborn is.
“If a pig fetus dies, it is not aborted as that would complicate pregnancy for the remaining live fetuses. Those piglets remain arrested in development and undergo some decomposition, normally resulting in an olive-colored, drab, piglet-shaped mummy,” Safranski says. “Stillborn piglets look completely normal and fully developed, because they are. How many ‘stillborn’ piglets are found if you take the piglets by C-section at term? None. A stillborn piglet was alive when his mother went into labor but died before being born.”
What Causes a Piglet to Die Prior to Being Born?
Safranski says it’s often due to suffocation. This can happen if the umbilical cord gets twisted, knotted or broken, or if the placenta detaches from the uterus prior to birth.
While a farm can have a stillborn rate of 10%, he says most sows do not. Stillborns tend to accumulate in a subset of the litters – typically older sows and those with large litters or long duration of farrowing.
“Long duration of farrowing can be problematic because the uterus is contracting to expel piglets, and there is some effect on the placenta of piglets not yet born. If the placenta loosens, the piglet loses its source of oxygen,” Safranski adds.
Management Tips to Prevent Stillborns
Preventing stillborn pigs serves as a huge opportunity for a farm. Once external factors such as infectious disease, high levels of mycotoxins in feed or environmental issues are ruled out, Bents suggests setting a goal for stillborn reduction on the farm.
Start by counting the number of meconium-stained pigs over a few days of farrowing and use this number (as a percentage of the total stillborns) as a goal for stillborn reduction. Set a goal that can be consistently achieved before shooting for the moon, he adds.
Bents and Safranski share three tips for producers to consider to maximize pigs born alive.
1. Monitor farrowing closely.
If duration of farrowing is a contributing factor to stillborn rate, and most stillborns come from a subset of the sows, how can that be addressed in the farrowing barn? Safranski says it’s simple – by attending farrowing. A farrowing monitor can recognize when a sow needs help and provide timely obstetrical assistance to reduce the number of stillborns by ¼ to ½ piglet per litter or more.
“This allows reduction in the number of piglets crushed, the number who suffocate in their placenta after birth, and the proportion not receiving adequate colostrum. Those are all benefits to the farm, but independent of the effect on stillborns,” Safranski adds. “From the 1990s through today, multiple data sets have demonstrated the value of attending farrowing on reducing the number of stillborns.”
Bents also suggests recording the time of each farrowing observation to ensure that the delay between pigs isn’t too long. On average, a pig is usually delivered every 15 minutes, so if all of the pigs are dry and the placenta hasn’t been expelled yet, it may be worth checking. He also encourages checking for any meconium-stained pigs, as this points to delivery difficulty of that pig.
Safranski adds, “This 15 minutes tends to get longer the later you go into the farrowing process. Later in farrowing, as the sow is getting more tired, intervention can take place more quickly.”
Look out for your sow’s well-being at farrowing. Wear OB sleeves – and put on a clean one for every sow – as diseases can move readily around the farrowing house during the delivery process, Bents says. Use lubricant during inspection to reduce trauma and swelling and move slowly and with the contractions so you don’t wear her out.
“If one sleeves a sow, prophylactic antibiotic treatment may be indicated. Talk to your vet to have an SOP to cover that,” Safranski says.
2. Adjust sows’ diet prior to farrowing.
Although there are many theories about feeding sows prior to farrowing, strong data from multiple research groups indicates the benefit of frequent feeding of smaller meals.
“As the time between a sow’s last meal prior to initiation of farrowing is reduced, her duration of labor and stillborn rate go down,” Safranski says. “Thinking about how to achieve frequent meal intake can be a powerful tool to help, especially as our sows have much larger litters than they did only 10 years ago.”
Bents says he finds a “happy medium” works best. He suggests feeding two small meals per day (usually, 2–3 pounds per feeding). It should provide enough energy for the sows but won’t produce a large fecal mass.
“Some producers will even top-dress the feed prior to farrowing with a pound of dextrose per day, divided between feedings, to give sows extra energy without adding a lot of volume,” Bents says.
3. Review the parity structure of the farm.
It’s important to understand the farrowing differences that may exist between younger and older females in the herd.
“Gilts tend to have narrower birth canals, which can increase the discomfort of the delivery process, while older sows seem to run out of energy toward the end of farrowing,” Bents says.
“I tend to lean a little heavier on inducing gilt litters if I have a good understanding of the farm’s average gestation lengths and good breeding records, just to try to avoid running long and getting potentially larger pigs, but this is typically more of a challenge in lower-total-born herds than in higher-total-born ones.”
Farms that provide a veterinary-approved anti-inflammatory or pain management support to gilts immediately prior to farrowing have also reported fewer complications and a faster transition back onto feed after farrowing, he adds.
Bents also tries to provide extra calcium to keep smooth muscle contractions going.
“I am very conservative with oxytocin usage so that, first, we don’t overdose the sow, and second, that we will definitely be able to tend to her farrowing once the shot has been given,” Bents says.
The modern sow is a complex creature and has achieved so many things. Unfortunately, higher litter size and subsequent increased duration of farrowing can contribute to the high stillborn rates seen in many sows today.
“Doing ‘whatever it takes’ to allow supervision of farrowing and encouraging frequent meals seem to be our best approaches to reduce this rate,” Safranski says. “Our farrowing monitors need to be attentive and have the tools to properly intervene.”
More from Farm Journal’s PORK:
Is it Time to Rethink Gilt Development?
Stop Chasing, Get Out in Front: SHIC Reports on 2020 Progress
