Farm-Scape, Episode 1285

Research at the Prairie Swine Centre shows pigs have a tendency to fight less when housed in larger groups.

In conventional systems grower finisher pigs are housed in groups of 20 to 40 pigs per pen. Scientists at the Prairie Swine Centre have been examining the social interactions and productivity of pigs housed in larger groups, focusing on group sizes of about 100 in a pen.

Dr. Harold Gonyou says the chief concern was that these pigs would have to fight more when establishing a hierarchy within the pen.

"We see the pigs as having two options to avoid that excessive fighting.

One would be that they form small sub-groups that would stay in one location in the pen and not move about.

If they did that then we would be faced with needing to provide feeders and drinkers scattered throughout the pen so that all pigs would have access within their home range.

The other approach would be for the pigs to adopt a tolerance strategy where they no longer felt that dominance status was important and when they encountered a strange pig they didn't have to try to establish dominance hierarchy with it and they would simply tolerate it and walk by.

Our evidence would indicate that it's this latter one that they're doing. The pigs do move around in the pen.

If you have feeders scattered throughout the pen, in fact, the pigs will visit every feeder in the pen.

They don't have a hesitation of moving around the pen so we don't think it's a sub-group formation.

We also don't see excessive fighting. In fact we'll quite often see less fighting.

These pigs simply do not fight very much in these large pens so they seem to have become very tolerant of other pigs".

Dr. Gonyou says the productivity of those pigs housed in the larger groups was either equal or within one percent of those housed in the smaller groups.

For Farmscape.Ca, I'm Bruce Cochrane.