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

Advantages of stall housing Feed intake Decreased aggression Individual health check

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

Large group housing

Large group housing

Pen Distribution and Feeding Station

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

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

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

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

Measurements Injuries and locomotion

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

Injury assessment

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

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

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?

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

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

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

Lower culling rate in Large groups Results Lower culling rate in Large groups

Measurements Behaviour Feeding behaviour Occurrence of aggression Time budget

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

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

Results Time budget Percentage of time spent lying or standing/walking

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

Results Saliva cortisol

Results P<0.05 P<0.05 Immunology

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

Measurements Reproductive performance

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

Results Farrowing rate

Individual productivity Results P=0.01 Individual productivity

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

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

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

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

Acknowledgments Funding provided by: Supervision: Special thanks to: 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