Stress and fear as possible mediators of reproduction problems in group housed sows: a review

Abstract

The number of herds with group housed non-lactating sows is increasing rapidly in Europe as a consequence of changed legislation initiated by elevated public concern for animal welfare. However, lower litter size and pregnancy rate in group housed compared to individually housed non-lactating sows has been observed in several on-farm studies. Based upon existing knowledge, it is considered whether stress and fear caused by social interactions are possible mediators of impaired reproduction in group housed sows. A review of 15 experiments with group housed sows showed that although the results are few and inconsistent, there are indications that stress and fear may be contributory reasons for the impaired reproduction seen in group housed sows and that possible initiators of stress and fear might be the mixing of unfamiliar sows and high stocking rate levels. A suggestion for indicators of stress and fear related reproduction problems suitable for use in practice are put forward.

Keywords:

• herd management
• indicators
• litter size
• pregnancy rate
• reproduction performance

Acknowledgments

John Erik Hermansen, Troels Kristensen and Lene Juul Pedersen are thanked for valuable comments on earlier versions of this paper.

Notes

Kongsted, A. G. (Department of Agroecology, Danish Institute of Agricultural Sciences, PO Box 50, DK-8830 Tjele, Denmark). Stress and fear as possible mediators of reproduction problems in group housed sows a review.

Additional information

Notes on contributors

Anne Grete Kongsted

Kongsted, A. G. (Department of Agroecology, Danish Institute of Agricultural Sciences, PO Box 50, DK-8830 Tjele, Denmark). Stress and fear as possible mediators of reproduction problems in group housed sows a review.