‘Active’ and calm sows are less prone to crush their piglets
Less ‘active’ sows were more prone to crushing their piglets in a recent trial that looked at the link between sow behaviour and their history of piglet crushing. That was just one of the unexpected findings of a study, carried out at Writtle College in Essex, that compared the behaviour immediately post-farrowing of sows with a history of piglet crushing and those without a single recorded mortality due to crushing.
The crushing of piglets by the sow is the main cause of pre-weaning mortality and has been reported to be responsible for up to 80% of piglet deaths. Studies have identified that sows maintain some stable behavioural traits over parities, for example response to a piglet scream test, and sows with a history of crushing piglets are more likely to stay inside a farrowing hut while housed outdoors.
“However, there is little information available regarding previous piglet-crushing history and its association with the behaviour of sows housed in farrowing crates,” said Writtle College’s Jonathan Amory, when he presented the findings of the trial to delegates at this year’s British Society of Animal Science’s annual conference.
“Sows with a history of piglet crushing showed different behaviour patterns to those that had never crushed a piglet,” he explained. “And contrary to expectations, the latter group of sows made more transitions between sitting/lying and standing than the sows with a history of piglet crushing.”
He said that this had previously been suggested to be the point at which piglets were most at risk from crushing. “But we now know that this may depend on other factors, such as how calm the sow is. In our study, sows with a history of crushing were more restless while lying compared with sows without a ‘crushing’ history. In fact, sitting up from a lying position was responsible for 24% of piglet trappings, which is higher than recorded by other researchers.”
Although the sow’s reactions to her piglets has previously been suggested to be an important factor in piglet survival there was very little attention paid by ‘crushing’ and ‘non-crushing’ sows to their litter before or after posture changes, regardless of whether a piglet had been trapped.
“This might suggest that piglet behaviour might play a more important role in influencing the incidence of piglet crushing,” added Dr Amory.
Presented to the British Society of Animal Science Annual Meeting, March 31 to April 2, 2008, Scarborough, UK.
F Ovink and Amory J: “The relationship between the behaviour of sows and their histories of piglet crushing.”
Proceedings of the British Society of Animal Science, pp12 http://www.bsas.org.uk/Publications/Annual_Conference_Proceedings
PDF of Powerpoint presentations available at http://www.bsas.org.uk/Members_Area/
summary (pdf) Presentation_012ovink (pdf)
