3 April 1998

Stroppy sows dont

make better mums

AGGRESSIVE sows are no better at looking after piglets, despite the notion theyre more protective and should be removed from the herd.

Those findings come from a study at ADAS Terrington pig unit by Cambridge University research associate, Jeremy Marchant, who has studied sow response to an unfamiliar stockperson. Sows are less aggressive in crates than in open farrowing pens, but level of aggression is not compensated by lower piglet mortality.

"Piglet mortality averages 14% in crates and 17% in pens," he says.

Aggression has been measured by monitoring the sows heart rate, behaviour and vocal noise response when approached and touched on the snout by a stockperson. Scores were recorded at four stages from parturition to weaning to quantify results.

Dr Marchant claimed theres no evidence to suggest aggression subsides as the sows get older. "It leaves the stockperson with the difficulty of aggressive stock. What we have to do is identify which gilts are aggressive and remove them from the herd."

Research will focus on establishing a link between heart rate response to human touch and level of aggression to predict which sows are likely to be aggressive at farrowing.