Farmscape for October 17, 2005  (Episode 1940)

Research conducted at the Prairie Swine Centre suggests sows entering their first breeding cycle face the greatest risk of stress related loss of productivity as a result of being mixed into groups.

Previous group housing studies at the Prairie Swine Centre have found mixing sows into groups prior to embryonic transplant results in a six percent loss of productivity.

In an effort to determine factors behind that reduction, scientists compared groups of sows focusing on mixing pre and post embryonic transplant and comparing static versus dynamic housing, familiar versus unfamiliar groups and looking at three different parity categories.

Graduate Student Megan Strawford says parity seemed to be the most important factor.

Clip-Megan Strawford-Prairie Swine Centre

We didn't find any housing or familiarity effects.

We did find there was differences in parity and it was really the first parity sows that were really undergoing a lot of social stress.

They had a lot more scratches from aggression at mixing, they were eating later in the feeding cycle, they were resting on the slats a lot more than the older sows and they also had higher salivary cortisol concentrations.

Cortisol is a hormone that is used to measure if an animal is undergoing stress.

It's really the young first parity sows that are going through the social stresses in the group but that's not to say they're the only ones.

Our fourth parity sows also had higher cortisol concentrations but they're probably also trying to maintain their position in the dominance hierarchy, rather than fighting for resources.

Strawford says the study suggests mixing should occur post embryonic transplant and that producers need to consider stress levels faced by those first parity sows and adjust management accordingly.

For Farmscape.Ca, I'm Bruce Cochrane.

       *Farmscape is a presentation of Sask Pork and Manitoba Pork Council