These data came from farms within the SMS database in which gestation system type was clearly defined. Consequently, the total number of farms and sows in the SMS database does not match the totals in the entire database.

Table 2 summarizes the differences of the 10 KPIs reported under the four gestation housing types defined above. Our discussion will focus on the most important traits — pigs weaned/mated female/year (PW/MF/Y), farrowing rate, number of pigs born alive and average mated female mortality. Other traits are important, certainly, but most are encompassed in these traits.

The data reinforces that the most widely used gestation housing system is individual stalls, and their average PW/MF/Y is 24.57. All of the other gestation housing options from this data set had lower PW/MF/Y: 22.6 for the farms with a combination of stalls and pens; 21.9 for operations with gestation pens only; and 22.3 for operations with gestation pens and computerized feeding stations.

Noteworthy is the difference between sow gestation stalls and the other three options which range from 1.96 to 2.65 pigs weaned per mated female, annually. Clearly, the alternatives to the gestation stall appear to cut into the profit potential of the operations utilizing them.

Farrowing rate was the best in operations utilizing individual gestation stalls (85.2%), followed closely by operations using gestation pens only (84.7%). Pens with computerized feeding stations or a combination of pens and stalls had similar farrowing rates — both slightly higher than 80%.

Similar trends were seen in the number of pigs born alive. Operations using gestation stalls led the way, averaging 11.3 pigs born alive/litter, while all other gestation housing options had poorer performance, averaging from ¼ to ½ fewer pigs born alive/female farrowed (Table 2).

The one advantage that pens and pens with feeding stations had over individual sows stalls and the stall-pen combination was in the area of sow mortality.

The lowest average sow mortality was with the pens-only option at 2.9%. Pens with computerized feeding stations were exactly twice as high with a 5.8% sow mortality rate. Notably, those operations with individual stalls and the stall-pen combination averaged 9% and 9.9%, respectively. The 7% difference in sow mortality with these systems is considerable and deserves further study.

Use Data with Care

As previously noted, some of these data should be taken with a grain of salt. Reports in the scientific literature show sow mortalities increase as farms get larger. Could herd size explain why the lowest mortality was observed in the operations with pens only, averaging 650 sows/farm, in this dataset?

The answer is not clear and cannot be identified from this data alone. The greatest production, from a weaned pig/mated female/year point of view, is from the gestation housing option with the largest number of sows per herd — those with gestation stalls.

However, a look at individual herd data shows that some of the units with sows in pens and equipped with computerized feeding stations are improving. Three of those units recorded over 25 PW/MF/Y for the most current 13-week period in this data set. Updates will confirm whether these improvements are sustainable.

Rethink the Stall

The question needs to be asked: “Have we given up on the gestation stall too early?”

Clearly, if we use sow productivity as a measure of the sows' well-being, then gestation stalls appear to be the favorable choice.

That is not to say that the pen gestation systems cannot work. Our European counterparts, and some U.S. operations, utilize a variety of gestation housing systems with success. Producers will have to evaluate and identify the gestation housing system that fits their genetics and management capabilities best.

Forcing all producers to adopt a pen gestation housing system is probably not the answer to the sow well-being question.

Seeking Feedback

The Benchmarking series will continue to focus on key production indicators in 2008. If you have thoughts or questions about how to best utilize this benchmarking information, contact Ken Stalder at stalder@iastate.edu; National Hog Farmer Editor Dale Miller at dpmiller@nationalhogfarmer.com; or SMS staff Ron Ketchem at ron.ketchem@swinems.com or Mark Rix at mark.rix@swinems.com.

Table 1. Third Quarter 2007 Database Benchmarking and Ranking

Key Performance Indicator	13-Week Benchmarking Data				52-Week Benchmarking Data
	Top 10%	Top 25%	All Farms	Bottom 25%	Top 10%	Top 25%	All Farms	Bottom 25%
Number of farms	42	105	420	104	46	115	463	114
Mated females	52,951	158,939	700,915	158,399	55,396	155,023	782,222	190,100
Pigs weaned/mated female/year	27.50	26.40	22.90	18.28	27.05	26.03	22.57	18.79
Wean-to-1st service interval	5.94	6.25	7.08	8.81	5.94	6.25	7.10	8.20
Farrowing rate, %	88.1	87.8	83.4	77.5	88.4	87.9	82.8	76.5
Total pigs born/female farrowed	13.23	13.05	12.31	11.68	13.06	12.88	12.20	11.73
Pigs born live/female farrowed	12.13	11.94	11.16	10.38	12.01	11.81	11.07	10.49
Pigs weaned/female farrowed	10.93	10.64	9.75	8.68	10.81	10.51	9.63	8.85
Piglet survival, %	84.6	83.3	80.9	77.0	84.8	83.4	80.6	77.1
Avg. age at weaning, days	19.8	18.8	19.0	18.8	19.2	18.8	18.8	18.7
Average parity	2.66	2.89	2.88	2.02	2.58	2.74	2.44	1.90
Avg. parity of farrowed sows	3.15	3.04	3.08	2.84	3.07	3.12	3.15	2.92
Avg. parity of culled sows	3.49	2.95	3.34	2.86	3.01	3.01	3.10	2.89
Source: Swine Management Services, LLC

Table 2. One Year Benchmarking Values by Different Type of Gestation Housing

Benchmarking Data	Pens with Feeding Station	Pens Only	Combination of Crates and Pens	Stalls
Number of farms	5	2	15	27
Mated females	4,788	1,300	22,273	70,677
Mated females/farm	958	650	1,485	2,618
Pigs weaned/mated female/year	22.32	21.92	22.61	24.57
Wean-to-1st service interval	7.63	6.65	6.89	5.89
Farrowing rate, %	80.2	84.7	80.7	85.2
Total pigs born/female farrowed	11.84	11.71	12.12	12.35
Pigs born live/female farrowed	10.91	10.78	11.02	11.28
Pigs weaned/female farrowed	9.61	9.39	9.74	10.11
Piglet survival, %	81.0	80.3	81.8	83.6
Average age at weaning, days	17.5	19.25	19.40	18.94
Average parity	2.34	3.03	2.32	2.26
Avg. mated female mortality,%	5.80	2.90	9.90	9.00