A note on the relationship between the behavioural response of lactating sows to humans and the survival of their piglets

The objective of this study was to examine the relationships, based on unit averages, between the behavioural responses of lactating sows to humans and the performance of sows in 25 farrowing units at a large commercial farm. The behavioural responses of 25 sows in each farrowing unit were observed at 2-4 and 16-18 days of lactation and a correlation analysis, using unit averages, was used to examine the behaviour-productivity relationships. Moderate and significant between-unit correlations were found between the behavioural response of lactating sows at days 16-18 to an approaching experimenter and the percentage of stillborn piglets. Units in which test sows were quicker to withdraw in the presence of the experimenter had a higher stillbirth rate than those units in which a reduced withdrawal response was displayed. The withdrawal response of sows in the close presence of the experimenter accounted for about 18% of the variance in percentage of stillborn piglets. While this study was a preliminary one examining the potential for the human-animal relationship to affect the performance of sows in the farrowing shed, the results indicate that high levels of fear of humans by sows may affect the survival of their piglets. The possible mechanisms whereby fear may affect piglet survival are considered. Clearly further research is warranted because of the important practical implications of this negative fear-productivity relationship on animal performance and welfare. (C) 1999 Elsevier Science B.V. All rights reserved.