Most sows in western Canada are housed individually in gestation stalls but several major pork processors, including Maple Leaf in Canada and Smithfield in the US, have pledged to phase out gestation stalls.

Dr Laurie Connor, the head of the University of Manitoba's Department of Animal Science, told those attending Hog and Poultry Days 2010 last week in Winnipeg when choosing the most appropriate group housing system several factors need to be considered but two are key.

Dr Laurie Connor-University of Manitoba

One is referred to as social management and that is how you are going to group the sows together, the size of the group, how you're going to introduce them into a group, mix them together, the social management aspect and then there's actually the feeding management or the feeding system.

A key to group housing is being able to feed sows as individuals so that you minimize any sort of aggression associated with competition for feed and then you can help then to maintain all of your animals in the type of condition that you want to, no fear of being sort of beat up basically over feed.

Dominance really only becomes an issue if you're competing for limited resources and feed would tend to be a limited resource in our confinement sort of situations because otherwise you end up with very fat animals.

You need to be able to provide a system such that the animals can have what they require in terms of feed intake without fear, without ending up having to fight for it every time.

There are many factors but key I think really are the management of the social aspect of group housing and the actual feeding system choice.

Dr Connor says producers need to make decisions based on what will work under their individual management and be aware of both the capital costs and the ongoing operating costs.