27 March 1998

Pig-pen aggression

GILTS in free access farrowing pens show more aggression towards the stockperson than those in farrowing crates, conference was told.

The level of aggression was independent of maternal success, which implied that such behaviour could not be equated with mothering ability and piglet survival.

But a link between heart rate response and human touch might encourage development of tests to predict which sows might be particularly aggressive at farrowing.

Work on sow aggression towards staff was undertaken by J N Marchant, Department of Clinical Veterinary Medicine, Cambridge.

Observations were based on 62 Large White x Landrace gilts, starting six to eight weeks before farrowing. Each gilt was fitted with a heart monitor.

Gilts were farrowed in crates or a group system with five individual strawed pens, a communal passageway and separate dunging area.

Those in pens had a higher overall aggression score than those farrowed in crates but aggression was not related to maternal success in terms of litter mortality. &#42