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Piglet Survival A Key Performance Indicator

This second in the Quarterly Benchmarking series will focus on preweaning mortality and a new term — piglet survival

Second in the Quarterly Benchmarking series will focus on preweaning mortality and a new term — piglet survival.

This series reinforces the importance of accurately collecting, then effectively interpreting, the data collected in our pork production operations.

Table 1 shows this quarter's 13- and 52-week summaries of key performance indicators (KPIs), which allows producers to track how each KPI changes over time.

New Performance Terminology

The “piglet survival” trait, developed by Swine Management Services (SMS), LLC in Fremont, NE, is routinely used in analyzing sow herd performance for their clients. Data in the adjoining table and graphs was also provided by SMS.

To calculate piglet survival, start with 100% and subtract the percentage of stillborn piglets and the percentage of preweaning death loss. This value can be calculated on a litter basis, but is more valuable when calculated on groups of sows, either a week's worth of farrowings in a large operation or on a batch of sows farrowing in a smaller operation.

The percent stillborn and percent mortality were added to Table 1 for this quarter's list of KPI values, so you can see exactly how the piglet survival is calculated. Later in the article, we will also calculate piglet survival over a period of time (weeks, and months).

Trait Value

Why do we want to look at this new trait?

Stillborn piglets and preweaning death loss represent opportunities to change management and improve production efficiency of a sow herd.

Obviously, it is impossible to generate additional pigs in a litter after conception has occurred. Therefore, the largest number of pigs that can be weaned and sold is limited by the number of total pigs born. Changing management procedures to reduce the number of stillborn piglets and preweaning mortalities represent an opportunity to improve piglet survival in most commercial.

The first challenge is determining whether a piglet was stillborn or died shortly after birth. It is important to distinguish between these two conditions, because the management actions necessary to improve the performance indicator are likely to be different.

To determine if a piglet was truly a stillborn, producers can remove the lungs and place them in a glass of water. If the lungs float, the piglet took at least one breath before dying and, therefore, is a death that should be classified as a preweaning mortality. If the lungs sink, the pig never took a breath, in which case the piglet can be classified as stillborn.

Over the years, producers have tried various management techniques to reduce the percentage of stillborn piglets. The most effective technique is having someone present during the farrowing process to ensure that each piglet is physically dried off or treated with one of the powder products now available.

Pigs expend a great deal of energy trying to keep warm shortly after birth. Drying them off quickly reduces the chances that they become chilled.

Additionally, the farrowing attendant can ensure that each piglet receives colostrum immediately after birth. The colostrum provides energy to the piglet, helps it maintain its body temperature, and provides the crucial antibodies to help the piglet ward off diseases.

Induced vs. Non-Induced Farrowings

In order to attend more farrowings, many herds induce sows to farrow by injecting them with a commercially available prostaglandin. This might not be the answer for every herd, however.

Using example herds from the SMS database, we are able to compare two herds — one with induced farrowings, the other with sows that farrowed at the end of their natural gestation period. These two herds were nearly identical in every way (number born alive, average parity of sows farrowed, etc.).

Many herds induce sows to farrow at Day 114 of gestation. The problem with this standardized practice is the gestation length of sows varies.

Figure 2 illustrates the variation in gestation length in the two herds. The brown bars represent the herd where farrowings were not induced; the orange bars represent the herd where farrowings were induced.

Notice the induced herd (orange bars) had a greater number of sows farrowing at Day 115 of gestation, and the sows farrowed over fewer days, when compared to the non-induced herd.

However, there is still some variation in the induced herd, because all sows do not respond the same way to the prostaglandin injection.

When induced farrowings are practiced, piglets may be small and may not thrive as well as pigs that are born to sows that have completed their natural gestation period.

When comparing these two herds (Figure 2), the induced herd had greater than a 17% preweaning mortality, while the non-induced herd had a preweaning mortality of only 7% for the same time period.

This comparison illustrates that the combination of induced and attended farrowings may not be the total answer. The practice may reduce the number of stillborn piglets, but in this case, preweaning mortality was still unacceptably high.

This example also helps illustrate the usefulness of the piglet survival trait as a KPI. The non-induced herd has extended the hours of some employees to be sure someone attends all farrowings.

The lower preweaning mortality figures are likely the result of the piglets going through a natural gestation length, being thriftier at birth and surviving until weaning.

In this case, the difference in preweaning mortality can pay for the additional hours required to attend farrowings in a herd where sows are not induced.

Management Changes Pay Off

Figure 1 (page 41) illustrates the piglet survival rate 11 weeks before and after changes in management of a 2,500-sow operation took place.

This herd made a management decision to extend the hours of farrowing managers to allow more attended farrowings, which almost eliminated induced farrowings. Employees handled the newborns in the same manner as when sows were induced. The only change was allowing the sows and their piglets to experience the natural gestation length and onset of farrowing.

In this herd, both the number of stillborn piglets and preweaning mortalities were reduced. Piglet survival improved 4.5%.

Records Help Target Efficiencies

These two examples illustrate how fine-tuning an operation through extensive record evaluation helps improve efficiency and bottom-line profitability.

Closer examination of the KPIs in Table 1 illustrate that even the best herds have an average piglet survival of only 85% in the short term (13-week summary) and 84.5% over the past 12 months.

Decreasing the percentage of stillborn piglets and preweaning mortality, thereby improving piglet survival, is an opportunity that nearly all herds could capture. The key is identifying how to improve these traits simultaneously so more pigs are weaned and move on to the next phase of production.

It is important to keenly evaluate production records and identify the KPIs that lead to improved efficiencies. Obviously, it is important to identify those areas where a relatively large impact can be made with little investment and changes to the operation. This is the “low hanging fruit” that we hear about.

In many cases, it simply requires renewed focus on the management techniques that we know make a difference.

Next Quarterly Report

The August benchmarking article in this quarterly series will focus on improving reproductive performance in the breeding herd.

If you have thoughts or questions about how to best utilize this benchmarking information, contact Stalder at; National Hog Farmer Editor Dale Miller at; or the SMS staff, Ron Ketchem at or Mark Rix at

View this table in a new window (Word format)

Table 1. First Quarter 2007 Database Benchmarking and Ranking
13-Week Benchmarking Data 52-Week Benchmarking Data
Key Performance Indicators Top 10% Top 25% All Farms Bottom 25% Top 10% Top 25% All Farms Bottom 25%
Number of farms 33 83 332 82 35 89 359 88
Mated females 41,736 132,809 563,281 109,774 39,185 134,985 615,328 124,828
Pigs weaned/mated female/year 27.16 26.04 22.21 16.14 26.81 25.62 22.52 18.85
Wean to 1st service interval, days 5.64 5.81 7.10 9.38 6.01 6.19 6.99 8.27
Farrowing rate, % 87.9 86.2 80.2 69.5 87.1 86.3 82.4 75.9
Total pigs born/female farrowed 13.06 12.87 12.18 11.54 13.10 12.73 12.15 11.71
Pigs born live/female farrowed 12.00 11.80 11.04 10.13 12.04 11.64 11.01 10.40
Pigs weaned/female farrowed 10.83 10.51 9.64 8.42 10.78 10.38 9.56 8.78
Stillborn piglets, % 5.9 6.3 7.1 8.7 6.0 6.5 7.1 8.4
Preweaning mortality, % 9.0 9.9 12.2 17.1 9.5 10.2 13.2 17.2
Piglet survival, % 85.1 83.8 80.7 74.2 84.5 83.3 79.7 74.4
Avg. age at weaning, days 19.6 18.7 18.7 19.0 19.3 18.5 18.8 18.8
Avg. parity 2.17 2.27 2.25 2.06 2.60 2.54 2.37 2.06
Avg. parity of farrowed sows 3.24 3.29 3.27 3.22 3.29 3.18 3.28 3.16
Avg. parity of culled sows 2.48 2.95 3.34 3.45 3.07 2.74 2.99 3.20
Source: Swine Management Services, LLC
TAGS: Reproduction