Every day you have to work hard to manage many risk factors within your pork production system. For the farrowing house, the priority is to get as many pigs born alive as possible, but you must also get those pigs off to the right start for a productive growth cycle.

Sarah Probst Miller, DVM, Carthage Veterinary Service, has compiled 14 primary risk factors to help improve both of those production aspects. She compiled the list by combing through research and scientific publications, along with consultations with colleagues and real-world experience.

Of course, there is an economic benefit to reducing the stillborn and pre-weaning mortality rates. She points to an estimate that shows a $6,000 net profit for every 1 percent reduction in the stillborn rate per 500 sows.

The first article in this three-part series appeared in the September issue of Pork. There Probst Miller outlined suggestions related to the first seven risk factors. This article discusses her recommendations for managing the next seven risk factors.

So, let’s see where your system stands and what areas you may need to tweak.

Risk factor 8
Misidentifying stillborns

Probst Miller says that in cases of high stillborn rates it’s important to distinguish between stillborns, mummies and early laid-on pigs.

“A good demonstration to clarify the difference between an early laid-on pig and a stillborn is to compare whether lungs float in water,” she says. “Stillborn lungs sink. Laid-on lungs float due to air inspired.”

There’s also a difference in appearance between a mummified fetus (death prior to parturition) and a true stillborn (death during parturition).  It’s wise to train your staff on what traits to look for so that they can identify a mummified fetus versus a true stillborn that could have been saved, she notes. It’s also important that your staff records these deaths accurately.

Risk factor 9
Prolonged labor

Prolonged labor can be instigated by disease pathogens, such as Eperythrozoon suis, calcium and/or phosphorus deficiency, anemic sows, large litters, induced hypocalcemia and elevated parity.

Correcting or preventing a prolonged labor can be achieved by working to remedy those causes, Probst Miller says.  “Using a farrowing synchronization product (typically oxytocin) 20 to 24 hours post-induction also can easily help reduce this risk.”

However, even though oxytocin can successfully speed up the birthing process, she cautions that you need to pay attention and manage the risk factors associated with oxytocin use by using a low dose, and consider restricting synchronization to high-risk sows.

It’s common for synchronization to require additional vaginal palpations. “Sows with additional vaginal palpations do have an increased stillborn risk, but it’s a risk that must be taken when a sow needs help or has an increased birth interval toward the end of the labor,” she adds. “There is a need for more research to determine if selective synchronization of older-parity sows or high-risk sows will keep stillborn rates low or reduce them.”

Risk factor 10
Heat stress in sows

Sows undergoing heat stress ranging from mildly high temperatures (73º F to 77º F) to very hot temperatures (77º F or higher) are at risk for increased stillbirths due to prolonged labor, epinephrine (adrenaline) release due to stress, hypoxia, hypocalcemia and other issues. “Optimally, the sow would farrow and lactate at 65º F,” Probst Miller explains. “Since the pig environment at birth is optimized at 93º F, we compromise in most barns and farrow sows with room temperatures around 70º F to 74º F, depending on the system. Clearly the sow does better the lower we can get the ambient temperature.” So, if baby pigs are dried or warmed shortly after birth and are provided with adequate localized heat, you can move toward the lower end of the temperature range for the sow’s sake, she notes.

Because hot summer months may increase heat-stress risk, additional cooling for sows may be necessary. The personnel who monitor sows as they farrow must be trained to identify those that are undergoing heat stress, and then provide them with additional cooling as well as farrowing assistance.

“An animal taking more than 40 breaths per minute is considered heat stressed on many farms. Other signs may be breathing more rapidly than in earlier labor, fatigue, skin discoloration, weakness, dull or stressed eyes,” Probst Miller notes.

Also remember that sows housed in hot environments while lactating have reduced milk yields, which can negatively affect pig weights and possibly pig survival. “Getting the room and localized temperature correct is essential to starting pigs right,” she says.

Risk factor 11
Born to a stressed sow

Any type of stress can cause a sow to release stress-related hormones such as epinephrine (adrenaline) and move into fight or flight mode. When adrenaline is released, the hormones that regulate the farrowing process decrease. This reduces the sow’s ability to deal with the offending stressors, Probst Miller explains.

She recommends paying attention to these common farrowing room stressors:

  • Processing piglets in the room where sows are farrowing.
  • The presence of an employee that the sow “does not like.”
  • Loud abrasive behavior by staff.

To promote a calm environment and to alert other employees that the farrowing room is a place where calm, quiet behavior is necessary, Probst Miller recommends working with the overhead lights off. “Working by the light of the heat lamps is very possible,” she says. If it’s impossible to work with the lights off, she suggests hanging a sign or flag on farrowing room doors to remind people that this is a “quiet” area.

Risk factor 12
Chronic illness in sow

Disease breaks, such as porcine reproductive and respiratory syndrome, and pathogens, such as Eperythrozoon suis, increase stillborn rates.  “When disease occurs, staff must be notified that increased vigilance and assistance during farrowing may be necessary,” Probst Miller says.

Don’t be complacent if yours is a high-health or stable-health herd. Employees then need to be proficient at identifying sows with injuries or illnesses prior to farrowing that may need additional farrowing monitoring, care or assistance.

“These sows should be identified and treated during gestation, and they should be flagged by the crew loading the room,” she notes. The sows should then be put in the same flagged category as high-parity sows, sows with a history of stillborns and sows with a history of high total born.

Risk factor 13
Vaginal palpation

Probst Miller cites 2002 research from Brazil that found sows that received vaginal palpation sometime during labor had eight times higher odds of having a stillborn piglet. “Vaginal palpation can be a valuable tool, but if done without reason or the proper skills, it can have negative effects,” she says.

Still, when a sow needs help, she needs help and delaying assistance could result in death, she adds. “So managing this risk is tricky, because you don’t want to ‘sleeve’ a sow if it’s not needed. But, if an employee suspects a sow and her piglet are at risk, getting the decision made and the sleeving done quickly and gently is essential.” In the end, every action has a risk and employees must learn to make wise decisions to best manage the risk.

Risk factor 14
Hypocalcemia in the sow

“A difficult labor, a labor where excess oxytocin is used or a long labor can all predispose a sow to becoming hypocalcemic,” Probst Miller says. “Calcium is an important part of the parturition event.  Release of intracellular calcium is necessary for uterine contractions.”

Therefore, it’s wise to work with your veterinarian and/or a swine nutritionist to determine if inadequate calcium levels may be causing farrowing problems for your sows. If that’s the case, you need to develop the dietary and management protocols for your specific production situation to resolve what is a fixable issue. 

Now, with these 14 risk factors, you and your staff are on the road to identifying areas that you need to address in order to get more pigs born alive and started right.

Editor’s note: The final installment in this three-part series will appear in the November issue of Pork. It will address ways to manage primary risks to help get pigs off to a better start.