The last two Production Preview articles focused on the seasonal effects on sow farm performance. This third and final article in the series will focus on production measures that affect pig survival rate – total born/mated female/year, pigs weaned/mated female/year, stillborn rate, preweaning death loss and piglet survival.

We will again use the dataset that includes 66 farms and 178,454 females. Forty-six farms (125,854 females) are located in the United States with an average herd size of 2,736 females; 20 farms are in Canada (52,620 females) with an average of 2,631 females. The data was collected by week for the last 104 weeks, ending on June 30, 2012, providing production data through two seasons.

Chart 1, total born/mated female/year, shows a range from 30.24 to 34.74 pigs to average 33.03 pigs/mated female/year. The two-year trend line shows an increase of about two pigs/mated female/year. Generally, we see a drop in total born starting in mid-October each year, which bottoms out in late-November, then bounces back to the yearly average by January. The green line (Canada) shows the same trend line of increasing total pigs born, however, the seasonal drop for summer matings is much less. In January through June 2012, several farms improved to 35 pigs/mated female/year or higher.

Chart 2 illustrates the spread in pigs born/mated female/year during the two-year period. The scatter graph shows each farm’s last two averages for the trait in a column, left to right. For example, the first farm produced 34.8 pigs/mated female/year in 2011, and then dropped to 31.9 pigs for 2012.

Chart 3 tracks pigs weaned/mated female/year, with U.S. farms averaging 26.28 (range: 024.54 to 27.68) and Canadian farms averaging 26.80 (range: 24.66 to 28.33). Like Chart 1, the trend line shows an increase of 1.8 weaned pigs/mated female/year for the two-year period, but the decline is shifted by about three weeks.

Chart 4, pigs weaned/mated female/year, by farm, shows only two farms weaned more than 30 pigs/year. Several farms fell below 24 weaned pigs/mated female/year.

Turning to stillborn rates, Chart 5 shows the overall average of 5.9%, a decline of about 1.5%, during the two-year period. Note the seasonal increase during summer farrowings and the peaks in early-August of both years. In U.S. farms, we see another peak in early February 2011. We’re not sure what happened, but it could have been a herd health issue.

It is interesting to note that as total pigs born increases, efforts to reduce stillborns (often the bigger pigs) has nudged pigs weaned higher. Chart 6 shows two farms held stillborn rates below 3% in 2012. Still, there are several farms at 7%, the average of the Swine Management Services Farm Benchmarking data base.

A closer look at the data shows there was a lot of week-to-week variation in preweaning mortality. In Chart 7, percent preweaning mortality, the overall average was 12%, ranging from 10.5 to 13.5%. Canadian farms averaged a little higher, 12.6%, with a wider range of 10.9 to 15.2%. While the week-to-week variation is notable, the seasonal effects are less during the 104 weeks.

When we looked at the most current 40 weeks in the dataset, we noted the preweaning mortality increased for the 20 farms in Canada. The opposite was true for the 46 U.S. farms, which showed a nice drop in preweaning mortality of about 3% during the most recent 20 weeks in the dataset.

Looking at percent preweaning mortality, by farm, we again see a lot of variation. A few farms are below 6%, but the worst farms are at 18% or more (Chart 8).

A few years ago, we developed the equation for piglet survival to correct for the variation in the way farms define and record stillborns and preweaning mortality. The formula is: 100% - (stillborn % + preweaning mortality %). The true way to determine if a pig was stillborn is to remove part of the lung and place in a glass of water. If it floats, the pig took at least one breath, therefore, it was not stillborn.

Chart 9, piglet survival, shows the U.S. trend line (blue) improving about 4%. The 20 Canadian farms recorded improvement for the first 60 months, then dropped to 78% in August 2011, then rebounded back to about 82%. Farms that save more pigs have made changes in how sows and pigs are managed at farrowing. Several farms have added one or two shifts for farrowing assistance to ensure someone is present to assist sows, reduce chilling by towel-drying pigs or applying drying agents at birth, and to make sure all pigs get colostrum by split suckling litters.

The data in these charts reinforce that summer heat creates a seasonal breeding effect on total pigs born. Stillborn rates increase in July and August, thus reducing piglet survival. Changes in farrowing management help save more pigs. Where would your farm rank in the data set?

Past “Production Preview” columns can be found at Click on “newsletters,” then the respective date of the Weekly Preview issue you are interested in.

Greeting of the Season

Mark and I appreciate all of the positive feedback and constructive suggestions from readers of the Production Preview columns. If there is a production area you would like to have us focus on in the future, feel free to drop us a note or give us a call. We wish you and your families a Merry Holiday season.

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

Mark Rix and Ron Ketchem    Swine Management Services, LLC