The Welfare of Gestating Sows in Conventional Stalls and in Large Groups on Deep-litter

1. The Welfare of Gestating Sows in Conventional Stalls and in Large Groups on Deep-litter Guillermo Karlen Animal Welfare Science Centre Department of Primary Industries, Victoria University of Melbourne

2. Advantages of stall housing • Feed intake • Decreased aggression • Individual health check

3. Welfare concerns • sows are unable to exercise • sows have limited social interaction • sows show signs of chronic stress (in some studies) • Use of stalls for gestating sows have been restricted in EU and banned in some countries

4. Large group housing

5. Large group housing

6. Pen Distribution and Feeding Station Feeding Station

7. Welfare in groups • Advantages • are able to exercise • have social interaction • less feed needed to maintain body condition • avoid aggression • Disadvantages • increased aggression • retaliation • more animals • feed intake control

8. Objective • To assess the welfare of gestating sows in large groups on deep-litter compared to individual stalls.

9. Experimental Design • Experiment 1: • 640 Sows • Two treatments • Conventional stalls (320 sows) • Large groups on deep litter (320 sows)

10. Experimental Design • Large groups: each replicate • 40 experimental + 45 non-experimental • N = 85 sows in 1 pen • Space allowance = 2.3 m2 per sow • Stalls: each replicate • 40 individually housed sows • Eight replicates of each treatment • Weekly allocation of replicates • 18 focal sows per replicate in each treatment • 6 from each parity group • Data collection: 27 weeks

11. Measurements • Injuries and locomotion

12. Assessments • Injuries at weaning and weeks 1, 9 and 15 of gestation • Scratches • Abrasions • Cuts

13. Injury assessment

14. Results Number of scratches was higher in large groups P<0.001 P<0.001 P<0.001

15. Results Number of abrasions was higher in Stalls P<0.001

16. Measurements • Locomotion score Sows were scored when standing, walking and trotting on a concrete pathway. • 0: sound • 1: difficulties putting weight on one or more limbs • 2: locomotion is obviously altered; signs of pain • 3: unable to walk, severe pain?

17. Assessments • Weaning previous to treatment • Week 9 and 15 of gestation • Stalls: allowed to walk 30 m before assessment • Large groups: after feeding

18. Results Locomotion better in Large groups P=0.001 P=0.001

19. Results Less severe locomotion problems in Large groups Sows scoring 2 or 3 P<0.001 P<0.001

20. Results Lower culling rate in Large groups

21. Measurements • Behaviour • Feeding behaviour • Occurrence of aggression • Time budget

22. Assessments • Week 1 and 9 of gestation • Feeding behaviour: feeding speed • Occurrence of aggression: 4 x 10 minutes of continuous observation • Time budget: instantaneous scanning every 5 minutes for 40 minutes

23. Results Aggression decreased between week 1 and 9 P<0.05

24. Results Time budget Percentage of time spent lying or standing/walking P<0.002 P<0.005

25. Measurements • Physiological measurements • Salivary cortisol • weeks 1 and 9 of gestation • Immunology • Week 16 of gestation • Haematology • Lymphocyte sub-populations

26. Results Saliva cortisol

27. Results P<0.05 P<0.05 Immunology

28. Results Immunology: Neutrophil/Lymphocyte ratio P<0.05

29. Measurements • Reproductive performance

30. Assessments • Farrowing rate • Total born • Born alive • Stillborn • Mummies • Average piglet birth weight • Average piglet weaning weight • Total litter (alive) birth weight • Total litter weaning weight

31. Results Farrowing rate

32. Results Individual productivity P=0.01

33. Summary • Early in gestation • Higher incidence of scratches in Large groups • Lower incidence of abrasions in Large groups • Higher salivary cortisol concentration in Large groups • The locomotion problems were less severe in Large groups

34. Summary • Late in gestation • Higher incidence of scratches in Large groups, although the number decreased substantially • Lower incidence of abrasions in Large groups • The locomotion problems increased in Stalls • Lower immune response in Stalls

35. Conclusion • Sows in Large groups faced higher challenges early in gestation, however they seem to decrease over time • In contrast, Sows in stalls faced increasing challenges later in gestation • Different systems have different problems • Design is more important than the system per se

36. Experiment 2 • Three treatments • Stalls (15 weeks) • Large groups (15 weeks) • 5 weeks in stalls and 10 weeks in large groups • 1080 sows • 14 months of data collection

37. Acknowledgments • Funding provided by: • Department of Primary Industries Victoria • Australian Pork Limited • The University of Melbourne • Supervision: • Prof. Paul Hemsworth (The University of Melbourne, Australia) and • Dr Harold Gonyou (Prairie Swine Centre, Saskatchewan, Canada) • Special thanks to: • Dr John Barnett • Dr Greg Cronin • Dr Emma Fabrega • AWSC staff and students • R&D staff at QAF Meat Industries