(First in a two-part series)

In the last 12 months, we have seen an increase in the number of farms doing batch farrowing in the Swine Management Services (SMS) benchmarking database, so we decided to take a closer look at the concept of group or batch farrowing and weaning.

During the mid-70s and into the ’80s, pork producers moved from farrowing twice a year to more intense, year-round farrowing to make better use of facilities and family labor. Group- or batch-farrowing systems were designed around planting and harvesting seasons when there was less labor available for working with the hogs. At that time, the industry began to move to more all-in, all-out (AIAO) use of farrowing and nursery rooms, a greater focus on sanitation and improved pig health. By increasing the number of pigs produced/sow/year, they effectively reduced the cost per pig.

There were several different approaches to the group/batch systems based on the number of farrowing rooms, nursery rooms and preferred weaning age of the pigs.

The simplest was the 2/12 system, which had two groups of sows farrowing every 12 weeks. A more intense system, the 3/8 system had three groups of sows farrowing every eight weeks using one farrowing room and one nursery. Pigs were weaned at 23 to 51 days of age, based on how long the boars were left in with the sows. A 4/5 grouping meant boars were only left with the sows for two weeks, which helped keep weaning age at about 21 days of age. A similar 5/4 grouping utilized one farrowing room that allowed for only one week of breeding, 13 litters/farrowing crate/year, and weaning at 16-23 days of age.

In addition, there were grouping systems based on multiple farrowing rooms and multiple nursery rooms. Some basic computer programs would print out the start date of each group, the date to put boars with sows, the date to remove them, a starting farrowing date and a date the sows were to be weaned. On some farms these dates were placed on a calendar so the producer would know what needs to be done each week.

However, there were some problems with some of the group/batch systems, such as when to add replacement gilts to a group, identifying returns to estrus and how to fit them into another group. The seasonal effects of summer heat on boars and sows also created variation in the farrowing rate and the number of pigs produced per group. Eventually, to improve production, producers moved to a 20/1 grouping system which is essentially a weekly farrowing program.

Why go back to less efficient grouping/batch systems? The main reason is being able to take smaller farrow-to-wean facilities and produce larger groups of weaned pigs to fit into larger nursery/finisher barns. Larger groups also lowered pig transport costs. Larger groups of Isowean pigs also commanded better prices.

An example of this approach would be a 700-sow farm with 120 farrowing crates. This farm would normally farrowing about 30 litters/week and wean 300-plus pigs/week. If the farm converted to a batch system – farrowing every four weeks – they would have five groups of sows, breeding about 142 sows/group. With a farrowing rate of 85%, they would farrow 120 sows/week. If the farm could wean 10 pigs/litter, they could wean over1,200 pigs/batch. This approach adds value to some of the older, smaller sow farms.

The SMS farm benchmarking database has 13 farms that use batch farrowing. Sow inventory ranges from 250 to 1,600 sows and farrowing crate count ranges from 40 to 300 crates. Most of the farms were farrowing every four weeks, with five batches of sows.

Table 1 shows the composite numbers from these farms, broken into the Top 10%, Top 25%, All Farms, and Bottom 25%. These farms averaged 24.96 pigs weaned/mated female/year (PW/MF/Y). All farms in the SMS data set averaged 24.44 PW/MF/Y. As the table shows, the batch farrowing farms’ production numbers are very good.

We’ve also broken down data on several production areas in Charts 1 through 7. Chart 1, Pigs Weaned/Mated Female/Year shows the range of these farms, averaging from 22.81 to 26 PW/MF/Y, with an average of 24.89 PW/MF/Y. Chart 2 shows wean-to-first service interval averaged 7.96 days vs. 6.94 days in the full SMS database. The interval of sows cycling ranged from 4.47 to 11.61 days. Chart 3 shows farrowing rate variation ranged from 79.8 to 93.1%, for a 52-weeks average of 84.1%. The full SMS database averaged 85.2% for the period. In Chart 4, Total Born/Female Farrowed averaged a very high 13.93 pigs compared to the full SMS database at 13.26 Pigs Born/Female Farrowed. The top farm was at 14.62 pigs.

The subset of batch farrowing farms includes several different genetic packages. Chart 5, Pigs Weaned/Female Farrowed, shows an average of 10.71, with a range of 10.06 to 11.41 Pigs Weaned/Female Farrowed. Piglet Survival, Chart 6, shows the batch farrowing farms only averaged 78.3% vs. 79.6% in the SMS database.

Chart 7, Female Death Loss Percent, reveals the death loss averaged 8.6%, with variation from 14.9% to just 2.1%.

Next week, we will discuss the pros and cons of batch farrowing systems and outline some of the pitfalls involved in changing from a weekly to a batch system.

Key Performance Indicators
Tables 2 and 3 (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: mark.rix@swinems.com or ron.ketchem@swinems.com.


Click to view graphs.

Mark Rix and Ron Ketchem
Swine Management Services LLC