6. Prolonged labor

   Prolonged labor can be instigated by disease, calcium and/or phosphorus deficiency, anemia in sows, large litters, induced hypocalcemia and later parity. But each is correctable and preventable.

   The use of oxytocin to synchronize farrowing can speed up the birthing process, however, the negative effects listed in risk factor #5 should be considered.

7. Born to a stressed sow

   Stresses can cause the sow to release stress-related hormones, such as epinephrine (adrenaline), and move her into fight-or-flight mode. When adrenaline is released, the hormones regulating the farrowing process lower the sow's ability to deal with the offending stressor.

   Common stressors include pig processing or loud, abrasive behavior by staff while sows are farrowing, or the presence of an employee that the sow “dislikes.”

   To promote a calm environment and to alert staff that this is a room where calm, quiet behavior is necessary, it is helpful to work with the lights off. Sows prefer to farrow at night, so why not simulate night?

   Sows experiencing heat stress ranging from mildly high temperatures (73-77°F) to very hot temperatures (over 77°F) are at risk for increased stillbirths due to prolonged labor, epinephrine release, hypoxia, hypocalcemia, etc. More than 40 breaths/minute is often considered heat stressed.

   The optimal temperature for the sow to farrow and lactate is about 65°F. Since the newborn pig's optimal environmental temperature is 93°F, we usually compromise and set room temperatures at 70-74°F. If baby pigs are dried shortly after birth and provided with adequate localized heat, room temperatures can be set at the lower end of the range for the sows' sake.

8. Vaginal palpation

   Vaginal palpation or “sleeving” can be a valuable tool to reduce stillborn rates, but if done without reason or proper skills, it can have negative effects, too.

   Even when done with reason, sleeving has a risk of increasing stillborns. Therefore, sows that have been “sleeved” once need increased vigilance and may need to be sleeved again to prevent more stillborns. It is another take-a-risk-to-lower-a-risk situation.

   Good hygiene and a clean, well-lubricated, disposable sleeve are essential. A monitoring card will help track a sow's natural farrowing interval and recognize whether vaginal palpation is warranted.

9. Born hypoxic (oxygen-starved)

   Low doses of oxytocin can help avoid a slowdown in cardiac frequencies in the fetus, rupture of the umbilical cord and meconium staining; it does not reduce the fetal mortality rate, but may increase the viability of the newborn piglet.

   An oxygen-starved pig has a higher risk of being weak, not getting enough colostrum and being laid on. Proper oxytocin use and how to resuscitate a baby pig born severely hypoxic must be a part of every farm's training.

10. No colostrum or inadequate colostrum

    Colostrum is one of the most important substances a pig receives in its life. It is a prerequisite for high health and low mortality from birth to slaughter.

    A pig's ability to absorb adequate amounts of colostrum depends on the amount consumed, the immunoglobulins (IgG) concentration, the timing of consumption in relation to intestinal closure, the teat nursed, competition between piglets and birth weight.

    A sow's colostrum production is independent of litter size or parity. Some feel it serves as “a good marker for the maternal quality of the sow.”

    Studies have shown that most pigs consume twice the amount of colostrum needed by 12 hours after birth. The smallest pigs, however, take 16-24 hours unless you intervene with split suckling. If you do not split suckle, this restricts crossfostering opportunities to 12 hours for the medium to large pigs and 16-24 hours for the smaller pigs.

    Since it is best to crossfoster pigs before the 24-hour mark due to teat territorialism and sow bonding with pigs, split suckling is a valuable tool for speeding up colostrum intake in small and late-born pigs.

    Another consideration associated with split suckling is that the ability of antibody proteins to move through the pig's gut decreases with time and the stimulus for these “holes” to shut down is the presence of milk in the gut. IgG intestinal closure is typically complete by 18 hours, post birth.

    Stomach tubing or bottle feeding of the sow's colostrum — or cow colostrum used as a substitute — has helped start small pigs that have not received adequate colostrum.

11. Born to a sow that had a tough labor (born later or last)

    Pigs born to a sow with a prolonged labor is at greater risk of anoxia — abnormally low oxygen levels. One study shows that when farrowing takes over six hours, the mortality rate is 21% compared to just under 12% for litters farrowed in less than six hours.

    Judicious obstetrical assistance and ensuring newborns receive colostrum within 12 hours is a great help.

    Others use this risk as a reason to continue to synchronize sows to farrow with oxytocin, regardless of her being a high or low-risk sow. It is yet another way to manage a risk with something that has a risk.

12. Not establishing cross-fostering guidelines

    It is important to develop early crossfostering principles that have a purpose. Large litters and light birth weights are the most obvious reasons to move pigs. Since pigs adapt quicker to a new teat when moved at a very young age, it makes sense to move them as soon as possible after colostral intake is ensured.

The philosophy, less is more, may be the best guidance when establishing crossfostering protocols:

• Minimize stress by crossfostering within the first 24 hours after birth.

• Count functional teats to determine sow's rearing capacity.

• Consider teat size and functionality.

• Transfer either the smallest or largest pigs from a litter to minimize movement.

• Small pigs are at greatest risk of not establishing teat fidelity. Studies have shown that small pigs have consumed enough colostrum, but they subsequently died from lack of energy — probably because they lost the battle for an available teat.

• Moving small pigs to a milk deck may be cost effective.

• Whoever does the crossfostering must be well trained, a good thinker and a quick decision maker.

*Condensed from a 2007 American Association of Swine Veterinarians preconference workshop presented by Sarah Probst-Miller, DVM, Carthage (IL) Veterinary Service; the complete paper is posted at: www.hogvet.com/cvs/articles/Day1CriticalCare.pdf.