Roughly, 1% of all sows farrowing have difficulty during parturition and require assistance. However, while total elimination is not possible, there are several action items available to help reduce the incidence, which in turn can improve pigs/weaned/sow.
It is a frustrating fact that stillbirths are a common occurrence in all farrowing rooms and the incidence is growing, which coincides with the overall increase in litter size. Even when farrowings are well attended and everything is going well, there will continue to be stillbirths. Roughly, 1% of all sows farrowing have difficulty during parturition and require assistance. However, while total elimination is not possible, there are several action items available to help reduce the incidence, which in turn can improve pigs/weaned/sow.
What defines a stillbirth? A piglet who dies during the birthing process without taking a breath. Primary indicators that a piglet was born dead are a fleshy umbilical cord, a thin and wet membrane around the piglet, and cartilage curled up on the bottom of the toes, which is usually worn off as soon as the piglet begins walking.
A definitive method to determine if a piglet lying behind a sow is a stillbirth is to perform a simple necropsy. A stillbirth piglet that has not taken a breath will have dark plum colored lungs; not pink, as one would look after taking a breath. If you are still unsure, the piglet’s lung can be placed in water. If the lung floats, that is because there is oxygen in the lung from taking a breath and the piglet can be verified as being born alive. If the lung does not float, the piglet never took a breath after being born and should be classified as a stillbirth.
As litter sizes increases, the industry has changed the metric from the average number of stillbirths/litter to the percent stillbirths of total born/litter. Ideally, stillbirths should be <8% of the total born. A goal of 6% and a caution when the stillbirth rate exceeds 7% should be in place.
The primary reason for stillbirths is uterine inertia (the uterus is no longer capable of expelling the piglets; uterine contractions stop). There can be many causes for uterine inertia.
It is important that farrowing staff can identify the signs that a sow is having difficulty farrowing and suffering from uterine inertia.
- One or two dry pigs.
- Obvious straining and contractions with no results.
- No new pigs farrowed within 30 – 60 minutes after the sow was last checked.
- Baby pig feces observed in sow discharge.
- Pay attention to older sows. They tire easier and uterine contractions may stop.
Once it is determined that the sow is having trouble, farrowing personnel should assist the sow immediately.
The reduction of stillbirths at your farm requires:
- Attending sows more frequently during the farrowing process,
- Care and attention to sows known to have a high stillbirth rate,
- Prompt intervention when uterine inertia occurs,
- Proper culling of high parity sows.
- If infectious disease is thought to be an issue, take time to consult with your herd veterinarian about your vaccine protocol and gilt acclimation procedures prior to entry and before the first mating.
On the following pages, we have provided a checklist of symptoms, potential causes, and helpful solutions to limit uterine inertia and decrease the number of stillbirths on your farm.
|1||Sow Age: |
Generally, as sow’s get older, they begin to have more stillbirths with each successive litter.
– As parity increases, typically so does litter size and sows become exhausted and uterine contractions become weaker or non-existent after the first few piglets are born.
– As the sows age, muscle tone is lost and their ability for continued contractions is reduced.
– Keep your sow herd age, or average parity, in at the appropriate level to minimize the impact on stillbirths from older sows.
– Farrowing personnel should watch older sows closely while farrowing to assist as needed.
|2||Sows history: |
Individual sows may have a history of having more stillbirths with each litter.
– Good record keeping and a quick evaluation will help you identify a sow that has a history of stillbirths with each litter she farrows.
– Marking the sow or the farrowing card of these sows so she gets careful attention as she is farrowing.
– Choice recommends culling sows with a history of high stillbirths.
|3||Larger litter size: |
As litter size increases, there is potential for uterine inertia and an increase in stillbirths.
– Check farrowing sows every 15 to 20 minutes..
– Know the signs of a sow having difficulty.
– Assist the sow as needed.
|4||Water intake: |
Reduced water intake can cause constipation and udder pains during farrowing which can lead to an increase in stillbirths.
– Check water nipples each time a farrowing room is empty and before filling.
– Water flow from a farrowing nipple should 0.5 gallons/minute (1.9 l/minute).
– Water meters located in farrowing rooms can be a good indicator that sows are drinking well.
– Water intake will range from 4-6 gallons/sow/day at farrowing and up to 12 gallons by 21 days of lactation.
|5||Gestation length: |
Stillbirths increase where there is a shortened or prolonged gestation period.
– There have been studies indicating that gestation periods less than 114 days and greater than 116 days can lead to more stillbirths.
– Accurate record keeping is key.
– Marking the sow or the farrowing card will help you keep track of sows with an irregular gestation length so she gets more attention as she begins to farrow.
– Induce sows with a known longer gestation period at day 116.
|6||Extended farrowing process: |
Stillbirth rates can increase in sows that give birth over a longer period.
– The normal length of time of the farrowing process can range from 3 to 6 hours and piglets are usually pushed out every 10 to 20 minutes, but that can vary.
– Sows can have several pigs in a short period of time and then rest or they can have one piglet and rest for one hour before having several piglets in succession.
– The longer the overall process takes, the increased chances of sow having stillbirths.
– Check farrowing sows every 15 to 20 minutes.
– Know the signs of a sow having difficulty.
– Assist the sow as needed.
– Have your nutritionist evaluate your lactation feed ration to make sure all components are as they should be.
Lack of exercise during pregnancy may increase the stillbirth rates.
– Sows should get up at least once per day. When checking sows after each feeding in both breeding and gestation and farrowing, make sure all sows are up and eating and drinking.
– This would be a good time to identify sows who are sick or lame and medicate as needed.
Farrowing house temperatures above 80 ᵒF/27 ᵒC increases the risk of stillbirths.
– Sows go into heat stress around 83 ᵒF/28 ᵒC.
– A hot sow will tire more easily during the farrowing process consequently increasing the potential of producing stillbirths.
A sow is most comfortable in a range from 50 to 70 ᵒF/10 to 21 ᵒC range while piglets like a temperature around
95 °F /35 °C. Managing these two environments can be difficult. As a result most producers today farrow between
70 and 74 ᵒF /21 to 23.3 ᵒC.
– Maintaining steady farrowing house temperatures.
– In hot summer months, make sure the cooling system is always in good repair and working properly.
|9||Sow body condition: |
Over-conditioned sows have more potential for farrowing difficulties and produce more stillbirths then a sow in ideal body condition.
– The farm should strive to achieve a body condition of 3.0 to 3.5 on a five point conditioning scale for farrowing sows.
– P2 backfat at farrowing should be 16-18 mm.
|10||Calcium deficiency: |
Calcium is an important part of the farrowing event. Release of intracellular calcium is necessary for the contraction of the uterus. A difficult labor, a labor where excess oxytocin is used, or a long labor can all predispose a sow to becoming hypo-calcemic, which may lead to uterine inertia.
– Limit the use of Oxytocin.
– Calcium injections can help reduce the time of the farrowing process, minimize uterine inertia, provide energy to weak sows, and calm excitable and savaging sows.
– Suggested 23% calcium gluconate dosages of 15cc/gilt and 20cc/sow. Check with your veterinarian for other potential dosage recommendations.
– Can be given at the first sign of farrowing or during the farrowing process.
|11||Pre-farrow breeding: |
Research from Europe, Theil, et al, indicates the timing of sow eating pre-farrow has an impact on how long it takes her to farrow as well as the number of stillbirths per litter. Increased time between feedings may result in a longer time to farrow. Research from Swine Management Service has indicated the same, sows that were not ad-lib fed prior to farrowing, had an additional 0.20 stillbirths/litter compared to those sows that were ad-lib fed pre-farrow.
– Ad lib feeding pre-farrow.
Diseases which can result in more stillbirths:
– Aujeszky’s disease (Pseudo-Rabies)
– Mycotoxins in Feed
– Consult with your herd veterinarian if you feel there may be a disease issue in your herd.