From the Editor – March 2006

Sow housing – no straight answer

What is your position on sow housing? When a student, a friend, or a colleague in the swine industry asks you for your thoughts on the topic, what do you say?

First-year veterinary students ask about sow housing. The students visit the university farrow-to-finish research facility and participate in five lectures about swine in a health management course. I ask the students to write down questions and comments about the farm visit and lectures, and then we discuss them in a 2-hour seminar. Sow housing is the most common topic of interest. However, my answer is not straightforward. In my mind there is no single correct response.

I was particularly interested to read the original research paper about sow housing that was written by Séguin, Barney, and Widowski in this issue. These authors conducted a study whereby they compared sow reproductive performance, skin lesions, and body condition among sows housed in moderately large, medium, and small groups and in individual stalls. The conclusion was that sows housed in groups experienced poor welfare for the first few days after mixing due to fighting. However, this did not last past the first few days. From a reproductive performance standpoint, the group-housed sows had better litter size and slightly larger pig birth weight than the individually housed sows. Please read the whole Séguin et al article yourself rather than taking my summary at face value.

I value this well designed, comprehensive research on sow housing. However, I would not use this one article to conclude that all sows should be raised in groups from weaning to farrowing. The sows in this study were group housed once they were confirmed pregnant. They were not observed immediately post weaning or during estrus. Often, this is the time when group housing is most difficult. If sows are individually housed at weaning they can be fed to condition – thin sows may be given additional feed to make up for weight lost in the farrowing room. Also, sows in groups ride one another when they are in estrus, which can cause lameness or the downer sow syndrome. Finally, these group-housed sows were provided with amenities not offered to all group-housed sows. Please read the article for the details, but just two examples, the feed was dropped in multiple places in the pen, and the pens had partial walls to provide escape routes and small sleeping quarters for groups of five sows.

I am sure you have all seen some group housing situations that lead to significant welfare problems in sows. For example, the sow that is beaten up by the others in the group and decides not to eat any more; the sow that is not allowed to eat with the others or the one that has to sleep in the gutter; the gilts that get sunburned or those that are outdoors in February and March with the wind howling, having to walk across the yard on ice or in mud up to their shoulders. These examples make me shudder when I hear that countries or states have banned individual sow housing. In my opinion, poorly designed and poorly managed group housing provides sow welfare that is significantly worse than most individual housing systems. Also, I believe that the level of management required for sows in group housing is higher than that for sows housed individually. For example, it is easier to identify a sow that is not eating in an individual housing system. It is also easier to provide extra feed for the thin sow and limit feed the fat sow. However, I do not believe that all sows should be housed individually. I have seen poor welfare in individually housed sows when the area is too small for their mature size and when sows suffer torn dewclaws. The potential for good welfare is higher in well-managed group systems than in well-managed individual housing systems.

If you were asked to respond to the first year veterinary students, what would you say? My response is "There is no ideal housing system for sows."

Then I elaborate: "I think sows benefit from well-designed, well-managed group systems. However, a poorly designed, poorly managed group system provides worse sow welfare than a typical individual housing system."

If producers are to move to a group housing system, they must incorporate some of the current research knowledge being generated by researchers, such as that of Séguin et al and others around the world. Specific attention to reducing competition at feeding time, providing escape routes, and allowing sows to form small stable groups are some key components. Most producers in Ontario who have moved to group systems have retained some of the individual sow housing facility. This enables them to house sows individually if they need extra attention or if they are not coping in the group. Producers who have intentionally retrofitted some of their individual gestation housing to include group housing tend to be pleased with the results. They believe that this has improved the welfare of their sows and made their job more rewarding.

–Cate Dewey