Published: January 11, 2008 02:41 pm            

Pork Professor: Controversy turns up research of gestation sow housing

Originally published in the December 28, 2007, print edition.

Individual stalls are the current primary housing system used for pregnant sows in the United States. Public sentiment, however, has been pushing to move away from individual housing toward group housing of gestation sows.

Almost a year ago, both Smithfield and Maple Leaf Foods indicated that they will be transitioning from individual gestation stalls to group pens over the next 10 years.

Just recently the Colorado Pork Producers indicated their plans to phase in group housing for pregnant sows. Previously, resolutions passed in Florida and Arizona banning individual sow gestation stalls in the future in those states.

Does this mean that individual stall systems are bad? No. Some individuals, primarily affiliated with animal rights activists, have chosen to voice their opinions over individual gestating sow stalls.

As an animal scientist, I feel we need to collect data and base decisions on solid facts and information instead of rhetoric and opinion. Which systems work best, individual stalls or group pens? The answer is “it depends.”

There are many different sow gestation options, and many ways to evaluate whether one system is better than another. One can evaluate based on performance, animal behavior, physiological responses, or other criteria.

Fortunately, our sow research unit at the Southern Research and Outreach Center in Waseca has been collecting data for nearly five years attempting to answer many of the questions regarding differences in gestating sow housing systems.

The 800-sow unit contains both individual gestation sow stalls (2 feet by 7 feet) and 50- to 60-sow group pens (22 feet by 42 feet) with electronic feeding stations. All sows are maintained on fully-slatted concrete floors.

Observations from our research at the University of Minnesota would suggest no clear cut advantage to either group or stall housing. Gestation stalls have been designed to provide sows with protection from other aggressive sows. Restriction in movement, especially in late gestation, however, can increase injuries, and may suggest a need for larger space allowances and crates for individually-housed sows.

Large group pens equipped with electronic feeding stations provide additional room for sows to roam and interact with each other, but also greatly increase stress level, aggression and injuries in these sows, especially when they are initially mixed together.

It is likely that modifications to the way group pens are designed and managed will be necessary in order to make them work more practically in today’s modern production systems.

        

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