An investment by the Pork Checkoff over the last decade of $1.2 million in scientific research on sow housing shows that a number of production systems can work well for pigs. However, the sow-housing issue continues to make headlines.

To date, eight states have enacted legislation limiting gestation stall use. Also, there has been a flurry of announcements from pork industry customers seeking to require suppliers to provide pork from sows housed in groups rather than gestation stalls.

According to Sherrie Niekamp, the Checkoff director of swine welfare, Checkoff studies related to gestation housing have ranged from evaluations of space allowances for group-housed sows, to an analysis of the cost of sow housing conversion, which researchers have projected to cost the pork industry $2.7 billion to $3 billion based on changes in the net present value of existing facilities.

“In any pork production system, the most important tool a producer has is the ability to provide care of each animal,” Niekamp says. “We hope the research findings will help producers fine-tune and improve the way they take care of sows by using science to evaluate housing systems.”

There are four main literature reviews that summarize the available science comparing individual housing to group housing. The reviews help the industry provide science-based answers on this issue.

• The Welfare of Intensively Kept Pigs, commissioned by the European Union in 1997, recognizes that there are advantages to using individual housing vs. group housing.

• A 2001 Australian study led by John Barnett showed that the design of the swine housing system is more important to animal well-being than the housing system, per se. It also emphasized that public perception issues should not be confused with animal welfare.

“In addition, this literature shows that the focus on housing systems may be to the detriment of recognizing the importance of another key factor in the pigs’ environment – the stockperson,” Niekamp says.

• A 2004 literature review commissioned by the Pork Checkoff and led by John McGlone at Texas Tech University concluded that gestation stalls or well-managed pens produce similar states of well-being for pregnant gilts and sows, in terms of physiology, behavior, performance and health.

• A literature review published in 2005 by the American Veterinary Medical Association concluded that all sow housing systems now in use have advantages and disadvantages, and there is no simple or objective way to rank housing systems for overall welfare.

• Based on the literature review analysis, the Checkoff’s Animal Welfare Committee has shifted funding priorities beyond comparing individual housing and group housing.

“The Checkoff is now focusing on improving key factors to optimize specific elements of particular housing systems,” Niekamp says.

For more information, contact Sherrie Niekamp at or at (515) 223-3533.