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Number Born Edges Upward, but Piglet Survival Continues to Decline

Piglet survival is defined as 100% minus the percent stillborns minus the percent preweaning death loss. Mummies are not counted in the total born, but fully formed stillborn pigs are counted.

Piglet survival is defined as 100% minus the percent stillborns minus the percent preweaning death loss. Mummies are not counted in the total born, but fully formed stillborn pigs are counted. We created this “piglet survival” calculation at Swine Management Services (SMS) four years ago to eliminate the games that are played with how stillborns are counted.

To improve preweaning death loss by 4% and hit the bonus targets set by the farm management, farm employees need only raise the number of pigs counted as “stillborns” by just half of a pig per female farrowed.

It is surprising how many people do not know the true definition of a stillborn or how to test whether a pig was truly stillborn vs. dying after birth. A postmortem confirmation of stillbirths is easily done by removing the piglet’s lungs and immersing them in water. If the lung sinks, the pig had not taken a breath and therefore may be classified as stillborn. If the lung floats, the pig was not stillborn. Once this is pointed out to employees, many will realize that it was a live born pig and a potential bonus pig at weaning time.

As we review farms’ production records, piglet survival is an area that we emphasize. Chart 1 (attached) illustrates piglet survival – ranging from <65% up to 95%. The weighted average is 80%. Therefore, if a unit farrows 1,000 pigs/week, the average unit loses 200 pigs. A closer look shows the top production unit loses only 50 pigs, while the worst unit loses 450 pigs. If you value a weaned pig at $35, the poorest unit is losing 250 more pigs than the average unit – or a loss of $8,750/week.

Chart 2 shows the trend lines of total born/female farrowed for the last three years. Total born has improved 0.60 pigs/litter. The genetic companies continue to make improvement in total pigs born; however, piglet survival rates continue to slip.

Chart 3 shows the trend for piglet survival during the last three years. Piglet survival of the top 10% of farms has declined over 2%, while all farms have declined over 1%. More and more producers we work with report larger litters born, but they are also carrying out more dead pigs. Their ability to manage the more productive sows is not holding up with the genetic ability to have more pigs. If your goal is to wean 28, 29, 30 or more pigs/mated female/year, some farrowing room management changes will need to be made.

The SMS database shows stillborns average 0.93 pigs/litter. If you can lower stillborns by 0.30 pigs/litter, with a total born of 12 pigs/litter, you can improve piglet survival by 2.5%.
Following are some ideas that can help reduce stillborns:

• Make sure employees are identifying and recording stillborn pigs correctly.

• Identify the “high risk” sows. These are sows with a history of farrowing problems and/or stillborns. These sows need to be identified on their farrowing cards, located in a certain farrowing room, marked with a marker, etc. These sows need extra attention during the farrowing process.

• If you are inducing your sows, review your procedures. In our work, we have found that inducing does not reduce the number of stillborns.

• Review the parity structure of your sow herd. Older sows have more stillborns.

• The procedure that has shown the most improvement in reducing stillborns is extending the hours of farrowing room attendants. When you look at data from your farm, you should find that most of the stillborns occur behind a few sows and they usually occur between the time you left the barn and when you returned the next morning. We conducted a study where we extended farrowing assistance to 15-18 hours/day during heavy farrowing periods – which increased attended farrowings to 85% of the sows. Stillborns dropped 0.32 pigs/litter. Some units that have tried this approach have not seen significant improvement. The key is to have the right, self-motivated person providing the assistance. The other key to piglet survival is reducing preweaning death loss. In the SMS data set, the average death loss for the most current 52-week period is 12.8%. Some suggestions for reducing preweaning death loss include:

• Reduce chilling by providing heat lamps behind and along the sides of the sow. Sprinkle or dip newborn pigs in a drying agent. Dry off piglets with a towel. Provide mats in crates to reduce drafts. Be sure to check for drafts caused by fans, air inlets and spaces under the doors.

• Measure some birth weights of pigs to an idea of the weight variation of newborn pigs. An average weight does not tell us much. You need to know the variation of weights. Pigs weighing less than 2 lb. at birth will have a 35% or higher death loss.

• Colostrum management on Day 1 of the pig’s life is a key to keeping pigs alive. All pigs need a large intake of colostrum to provide the needed antibodies and milk with higher protein to get the pigs warmed up and aggressive. As litter size increases, there is more competition for the limited amount of high quality colostrums so split suckling of all piglets will allow the small, less aggressive pigs to get colostrum.

• Cross fostering of pigs should be minimal to leave as many of the birth pigs with their mother. All the cross fostering must be done within 24-48 hours. Pigs that begin falling out after 48 hours need to be removed from the litter and either placed on a nurse sow or in a deck with supplemental milk replacer.

• Problem pigs need to be euthanized as soon as they are found so they do not affect the rest of the pigs on that litter. “Problem pigs” are low birth weight, low viability, pigs or pigs with defects, injuries, or health-challenged pigs. Generally, this does not increase preweaning death loss, but rather results in fewer pigs euthanized at weaning time and improves performance of the remaining pigs in the litter.

• People have the biggest impact on preweaning death loss. You should have your most detail-oriented, most experienced people managing the pigs at birth. Ongoing training of employees assigned to assist farrowings is important. These must be the most dedicated, compassionate employees. If you are going to invest in genetics with a high potential for producing more total pigs, make sure the best management practices are applied by your best people.

Key Performance Indicators
Tables 1 and 2 (below) provide 52-week and 13-week rolling averages for key performance indicators (KPI) of breeding herd performance. These tables reflect the most current quarterly data available and are presented with each column. The KPI’s can be used as general guidelines to measure the productivity of your herd compared to the top 10% and top 25% of farms, the average performance for all farms, and the bottom 25% of farms in the SMS database.

If you have questions or comments about these columns, or if you have a specific performance measurement that you would like to see benchmarked in our database, please address them to: or

Click to view graphs.

Mark Rix and Ron Ketchem
Swine Management Services, LLC