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Should You Consider Batch Farrowing?

A look at key database numbers shows more farms are switching to a batch farrowing system. Benefits include the ability to meet the need for a larger, single source of healthy pigs at weaning. And there may be a PEDV prevention benefit too.

Over the last few years we have seen an increase in the of number farms in the Swine Management Services (SMS) Farm Benchmarking database that have switched to a batch farrowing system. More farms are either considering conversion, or have converted to batch farrowing in order to meet the need for a larger, single source of healthy pigs at weaning. Producers want to be able to fill finisher facilities so they can be managed all-in and all-out.

The most recent health challenge of porcine epidemic diarrhea virus (PEDV) to the swine industry has also made producers think about moving from weekly farrowing to batch farrowing. This creates a system where there are weeks with with no sows farrowing. The practice may make it easier to clean up facilities after a disease break and slow the incidence of re-breaking with the virus. We have heard of batch farrowing farms that lost one batch of pigs to the virus and were right back to normal when the next batch entered farrowing a few weeks later. This down-time allowed the sows to develop immunity to the virus when no pigs were being farrowed.

By way of background, we wrote a two-part series on batch farrowing in September 2011 - How Batch Farrowing Impacts Production and An In-depth Look at Batch Farrowing.

The data set for this article was only 13 farms that range in size from 250 to 1600 sows. Pigs weaned/Mated female/Year for the SMS database at the time was 24.48 pigs versus the batch-farrowing farms at 24.89 pigs, with the top farm achieving 26.00 pigs. Farrowing rate for the entire SMS system was at 85.2%, versus batch farrowing farms at 84.1%. Total born/Female Farrowed for SMS as a whole was 13.26 pigs, with batch-farrowing farms at 13.93 pigs Born/Female Farrowed.

Digging into the numbers

In Table 1 you will find several batch farrowing options. Most of these were used back in the early 1970s when producers started trying to get their farrowing systems more organized as they moved away from just farrowing two groups of sows per year. The transition occurred because producers wanted to farrow sows year-round in an organized system and flow.

You can see as you add more groups, the weaning age goes down. However, the pigs per crate and turns per year of the farrowing facilities go up. Most of the batch systems today are either 10/2/1 which is 10 groups of sows farrowing every 2 weeks with a 1 week breeding period or 5/4/1 which is 5 groups of sows farrowing every 4 weeks with again a 1 week breeding period. Both systems allow for 13 turns of the farrowing facilities each year.

For the article we selected farms that were at 22+ pigs weaned/mated female/year for the last 52 weeks. In Table 2 and 3 is data for the SMS at 626 farms with average inventory of 1,838 females per farm and in Table 4 and 5 are 40 batch farrow farms with average inventory of 775 females. The range in size of the batch farrow farms was from 237 to 1,655 females with 12 of the 40 at 1,000+ females.

There are many production numbers in the tables for you to review. The 52 week average for Pigs Weaned/Mated Female/Year for SMS was 25.95 pigs with Top 10% at 30.51 pigs versus Batch farms average of 26.34 pigs with Top 10% at 30.12 pigs.

In looking at Farrowing Rate for SMS average at 86.4% with Top 10% at 91.2% versus batch average at 86.2% with Top 10% at 90.4%. Female Death Loss percentage for SMS averaged 7.5% with Top 10% at 6.0% versus a batch average of 7.2% with Top 10% at 5.3%.

There are also 7 distribution charts to show the spread in production numbers for the SMS data set of 626 farms with 1,150,329 females and the System (red area on the bottom of the blue columns) which are the 40 batch farrowing farms with 29,828 females.

Wherever you see a red diamond above a column it means there is at least 1 batch farm in that column. Chart 1 Pigs Weaned/Mated Female/Year shows SMS average of 25.95 with batch (called System farms in the charts) at 26.34. Both approaches had sows farrowing at 30+ pigs.

Chart 2 Wean to first service interval has SMS at an average of 6.50 days verses batch at 7.35 days. Because the batch farms are not breeding every week there are more weaned females that are either culled that did not cycle during a breeding week or are held for the next breeding cycle. That increases there wean to first service by skipping at least one heat cycle.

Chart 3 Farrowing Rate shows the average at 86.4 and 86.2% with both having top farms at 92+%. When you look at Chart 4 Total Born/Female Farrowed you see SMS at 13.90 pigs with batch at 14.12 pigs. Is there some advantage to the batch farms by having some of the females skip a weaned heat before being rebred. Chart 5 Pigs Weaned/Female Farrowed has SMS at an average of 10.86 pigs versus batch at 11.16 pigs. Since most for the batch systems have none or a limited number of nurse sows they have to put more pigs on every sow at the start of a batch so they are pushing the sows harder to wean more pigs.  

Chart 6 Piglet Survival has SMS average at 79.3% with Top 10% at 84.9% versus batch average of 80.1% with Top 10% at 83.4%. The chart shows both groups having some farms at 88+% piglet survival. Last distribution Chart 7 Female Death Loss shows SMS at 7.5% and batch at 7.2% with both systems having some farms at a <2% female death loss.

There are some farms in the industry that need to evaluate the pros and cons of going to a batch farrowing system. If you need larger groups of single source pigs to improve your pigs flow to more all-in and all-out you may want to consider batch farrowing.

One of the big problems with batch systems will be more concentrated breeding with 4 weeks of sows bred in one week. This approach could benefit an operation by being able to have more labor on big work weeks so more sows are attended at farrowing to help improve piglet survival. It may be time for your farm to consider batch farrowing. 

At SMS, our mission statement is to provide “Information solutions for the swine industry.” We feel with the creation of the new Farm Benchmarking database we now have more detailed information to share with the swine industry. If your farm would like to be part of the Farm Benchmarking database, or if you have suggestions on production areas to look at, feel free to e-mail or call us. We enjoy being a part of the National Hog Farmer Weekly Preview team.

Previous Production Preview columns can be found at

SMS Production Index

Table 2 and 3 above provide the 52-week rolling averages for 11 production numbers represented in the SMS Production Index. The numbers are separated by 90-100%, the 70-90%, the 50-70%, the 30-50% and the 0-30% groups. We also included the 13-week, 26-week and 12-quarter averages. These numbers represent what we feel are the key production numbers to look at to evaluate the farm’s performance.  

If you have questions or comments about these columns, or if you have a specific performance measurement that you would like us to write about, please contact: [email protected] or [email protected].

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