The Animal Welfare Science Centre Evaluation of sow stall dimensions John Barnett Animal Welfare Science Centre, Department of Primary Industries, Werribee

The Animal Welfare Science Centre 2  Stall housing is a controversial welfare issue for the pork industry  Criticisms of individual (stall) housing of sows –sows unable to exercise –limited social contact between sows –restriction of “naturalistic” behaviours  eg. dunging vs lying vs feeding area  40-60%(?) of gestating sows in Australia are stall housed  ~26%(?) of Australian sows are stall housed for 15 weeks / parity –concern over long-term individual housing (15 weeks) in stalls then crates  Code of Practice (welfare) defines minimum stall dimensions: –stall width = 0.6 m –stall length = 2.0 m (“clear space”: excludes feeder and water facilities) Background

The Animal Welfare Science Centre 3  Stalls banned in some countries –Sweden, Norway(?), Finland (2006), Switzerland (2007), Netherlands (2008), Denmark (2014)  Restricted time in stalls –European Union - maximum of 4 weeks post-mating from 2013 –New Zealand - (recommendation only at this stage) maximum of 6 weeks post-mating from 2009 and 4 weeks post-mating from 2013 (to be reviewed in 2009) (new stalls max of 4 weeks post-mating) Overseas recommendations on stalls

The Animal Welfare Science Centre 4 Cortisol concentrations in 4 housing treatments (nmol) From Barnett et al., 1991b

The Animal Welfare Science Centre 5 To determine: 1) the effects of stall dimensions on the welfare of sows 2) if there is a minimum time in stalls that results in improved reproduction without compromising sow welfare Objectives of Project

The Animal Welfare Science Centre 6 Evaluate the effects of: 1) Sow stall dimensions on welfare 2) Time in sow stalls on reproduction and welfare - commercial facility 3) Sow stall length and time in stalls on reproduction and welfare - commercial facility Student project: 4) Effects of housing in stalls and implications for forming social relationships Experiments to:

The Animal Welfare Science Centre 7  2 years  4 replicates in time  7 treatments (3 x 2 factorial) plus external, negative control  Factors examined:  Stall length (2.0 m vs 2.2 m vs 2.4 m)  Stall width (0.6 m vs 0.75 m)  External, negative control = tether stalls  Positions of treatments (banks of stalls) randomised between reps  4 sows per bank of stalls  2 non-experimental and 2 experimental sows  56 experimental & 56 non-experimental sows  parities 2-6 Experiment 1 - Sow Stall Dimensions

The Animal Welfare Science Centre 8 Conventional width stall (0.6 m wide) Wide stall (0.75 m wide) Stall width

The Animal Welfare Science Centre 9 Stall length 2.0, 2.2 and 2.4 m long in banks of 4

The Animal Welfare Science Centre 10 (0.6 m wide) Tether stall - control

The Animal Welfare Science Centre 11 Measurements 1) Sow physiology Surgery to implant catheter in cephalic vein at ~8 weeks into treatment day-time profile of plasma cortisol concentrations cortisol response to ACTH injection cell-mediated immune response 2) Sow lameness and live weight measured at entry and exit from treatments

The Animal Welfare Science Centre 12 Measurements 3) Sow behaviour post-feeding & “at rest” Video recording at ~7 weeks after entry to stalls – level of activity – social behaviour aggression affiliative behaviour (lying together vs apart) – angle of turn in stalls

The Animal Welfare Science Centre 13 Results - cortisol concentrations Width of stall Length of stall Tether 0.6 m 0.75 m 2.0 m 2.2 m 2.4 m Total cortisol conc. nMol 18.4 p 25.5 q Free cortisol conc. nMol 2.3 x 3.0 y 2.7 b 2.3 a 2.9 b 3.5 a,b: P<0.05; x,y: P<0.01; p,q: P<0.001 Free cortisol concentrations were lower in the 0.6 m wide stall & the 2.2 m long stall

The Animal Welfare Science Centre 14 Results - response to ACTH Width of stall Length of stallTether 0.6 m 0.75 m 2.0 m 2.2 m 2.4 m Total cortisol conc p 25.5 q pre-ACTH nMol Total cortisol conc a 3.02 b 2.95 q 2.76 p 3.02 q 3.13 post-ACTH % increase (log value) a,b: P<0.05; p,q: P<0.001 In a chronic stress response the response to ACTH is increased There was a lower response to ACTH in the 0.6 m wide stall and the 2.2 m long stall

The Animal Welfare Science Centre 15 Results - cell mediated immunity Width of stall Length of stallTether 0.6 m 0.75 m 2.0 m 2.2 m 2.4 m Cell mediated immunity b 91.2 a 91.1 pq q 89.1 p 81.7 (% increase in skin thickness) a,b: P<0.05; p,q: P<0.001 The greater the % response the “better” the animal’s immune system (higher response in 0.6 m wide stall and 2.2 m(?) long stall)

The Animal Welfare Science Centre 16 Results - Behaviour Activity Post-feeding observations: sows in 0.75 m wide stalls were more active (86% vs 74% of time; P<0.05 ); and took longer to lie down (101 min vs 86 min) No effects of treatment on aggression

The Animal Welfare Science Centre 17 Results - Affiliative behaviour (forward index) Index score of the preference of sows to occupy the same spatial alignment as their neighbours during the 2-h observation period ie. heads of neighbours at the front of the stall Width of stall Length of stall Observation period 0.6 m 0.75 m2.0 m 2.2 m 2.4 m Post-feeding Afternoon A negative index indicates that neighbouring sows were separated. A positive score indicates that neighbouring sows were together. A score close to zero implies the spatial alignment between neighbouring sows was random. Sows were generally lying apart (ie. lack of head to head contact)

The Animal Welfare Science Centre 18 Results - Angle of turn (post-feeding) Width of stall Length of stallTether 0.6 m 0.75 m 2.0 m 2.2 m 2.4 m Mean turn angle° 38 p 50 q 48 b 42 a 41 a 36 Mean maximum angle° 47 x 59 y 61 y 50 x 49 x 44 a,b: P<0.05; x,y: P<0.01; p,q: P<0.001 Conventional stall width (0.6 m) Wide stall width (0.75 m) Angle of turn greater in 0.75 m wide stall and 2.0 m long stall

The Animal Welfare Science Centre 19 Summary - Physiology Welfare improved in: 0.6 m wide compared to 0.75 m wide stalls based on lower total and free cortisol concentrations reduced responsiveness to ACTH increased immunoresponsiveness 2.2 m long stalls compared to 2.0 m long stalls based on lower free cortisol concentrations reduced responsiveness to ACTH increased immunoresponsiveness (vs. 2.4 but not 2.0 m long stalls)

The Animal Welfare Science Centre 20 Summary - Behaviour Behaviour data inconclusive: No effect on social behaviour? wider stalls allowed sows to turn more 2.4 m long stalls allowed more movement how are these social behaviours perceived? eg threatening Affiliative behaviour generally negative scores indicates sows preferred to be apart at front of stall

The Animal Welfare Science Centre 21  Experimental study on stall dimensions –stall divisions were horizontal bars –no positive control treatment Constraints

The Animal Welfare Science Centre 22  Stall Width –improved welfare with a stall width of 0.6 m stall Length –improved welfare with a stall length of 2.2 m Overall conclusions It is the design of the system rather than the housing system per se that is important to welfare

The Animal Welfare Science Centre 23 A collaborative project between:  Animal Welfare Science Centre / Department of Primary Industries  Australian Pork Limited Thanks to: co-researchers: Greg Cronin, Paul Hemsworth technical staff: Lisa Newman, Samantha Borg, Bruce Schirmer and AWSC students at DPI Werribee Thanks