When I began graduate school in 2003, one of the major research studies I worked on was evaluating the impacts of 3 different group-housing space allowances on gestation sow welfare as compared to housing gestating sows in individual stalls. That study was one of many studies funded by the Pork Checkoff at the time. While the first ballot initiative restricting the use of gestation stalls had passed in Florida the year prior, the issue of gestation housing had landed on the US swine industry’s radar a decade prior when the European Union had passed a directive restricting gestation stall use in 1991 (updated in 2008).

Three separate reviews of the scientific literature were conducted to compare group and individual housing systems and the impact they have on sow welfare. All three literature reviews came to similar conclusions – the advantages and disadvantages of gestation housing systems are qualitatively different and, therefore difficult to compare overall welfare.^1-4 One review added, “In fact, the focus on housing systems may have been to the detriment of recognizing the relative importance of another feature of the commercial pig’s environment, that is the stockperson.”¹ The conclusions of these reviews served as the basis for the development of both the AASV (aasv.org/aasv/position-sowhousing.php) and AVMA (avma.org/resources-tools/avma-policies/pregnant-sow-housing) position statements related to sow housing.

Fast forward 2 decades to 2022. Millions of dollars have been invested in public and private research of gestation sow housing. Gestation sow housing resources have been developed and experiences shared through numerous outlets. Pig farmers and equipment manufacturers are often featured speakers at industry meetings, including the AASV Annual Meeting, to share their experiences with building, implementing, and managing gestation sow housing systems. A few examples of available sow housing resources include:

• A series of factsheets that address the key decisions to be considered when choosing a housing system (lms.pork.org/Tools/View/sow-housing-options)
• A series of guides to assist caretakers in successfully managing each type of housing system (lms.pork.org/Tools/View/sow-housing-management).
• A financial comparison tool that enables producers to economically compare group sow housing systems (canr.msu.edu/resources/sow_housing_options_tool)
• Outputs from Canada’s National Sow Housing Conversion Project (groupsowhousing.com)

No matter what gestation sow housing system a client may elect to use, veterinarians have opportunities to protect pig health and welfare by providing science-informed guidance. These opportunities may come in the form of interactions with individual clients, marketplace stakeholders, or state/federal policy makers. California’s Proposition 12 is the latest opportunity for veterinarians to provide science-informed guidance on sow housing issues. The AASV submitted comments in response to the California Department of Food and Agriculture’s proposed rulemaking for Proposition 12. As the legal challenge to Proposition 12 advances to the US Supreme Court, AASV has submitted an Amicus Brief that will emphasize the AASV’s position on sow housing and share scientific evidence supporting the use of various types of housing systems to protect pig health and welfare, food safety, and public health.

Like all things in swine production, there is no one-size-fits-all solution for gestation sow housing. Ultimately, producers must do what is best for their animals, their employees, their facilities, and their marketplace. Veterinarians can support producers by helping them make science-informed decisions.

Sherrie Webb, MSc
Director of Swine Welfare

References

1. Barnett JL, Hemsworth PH, Cronin GM, Jongman EC, Hutson GD. A review of the welfare issues for sows and piglets in relation to housing. Aust J Agric Res. 2001;52:1-28. https://doi.org/10.1071/AR00057

2. McGlone JJ, von Borell EH, Deen J, Johnson AK, Levis DG, Meunier-Salaun M, Morrow J, Reeves D, Salak-Johnson JL, Sundberg PL. Compilation of the scientific literature comparing housing systems for gestating sows and gilts using measures of physiology, behavior, performance, and health. Prof Anim Sci. 2004;20:105-117. https://doi.org/10.15232/S1080-7446(15)31285-7

3. Rhodes RT, Appleby MC, Chinn K, Douglas L, Firkins LD, Houpt KA, Irwin C, Sundberg P, Tokach L, Wills RW. A comprehensive review of housing for pregnant sows. JAVMA. 2005;227:1580-1590. https://doi.org/10.2460/javma.2005.227.1580

4. McGlone JJ. Updated scientific evidence on the welfare of gestating sows kept in different housing systems. Prof Anim Sci. 2013;29:189-198. https://doi.org/10.15232/S1080-7446(15)30224-2