1. Impact of Stocking Density and Group Size in Enriched Cage Housing on Hen Behavior, Welfare and Performance Tina Widowski 1 ; Linda Caston 1 ; Steve Leeson 1, Leanne Cooley 2 ; Stephanie Torrey 3 ; Michele Guerin 4 1 Departments 1 Animal & Poultry Science and 4 Population Medicine University of Guelph 2 L.H. Gray and Son Limited 3 Agriculture and Agri-Food Canada (AAFC) Canada Impact of Stocking Density and Group Size in Enriched Cage Housing on Hen Behavior, Welfare and Performance Tina Widowski 1 ; Linda Caston 1 ; Steve Leeson 1, Leanne Cooley 2 ; Stephanie Torrey 3 ; Michele Guerin 4 1 Departments 1 Animal & Poultry Science and 4 Population Medicine University of Guelph 2 L.H. Gray and Son Limited 3 Agriculture and Agri-Food Canada (AAFC) Canada

2. Enriched Cages Provide the hygiene and health benefits of conventional cages (Tauson, 2005)Provide the hygiene and health benefits of conventional cages (Tauson, 2005) Production comparable to conventional cagesProduction comparable to conventional cages Perches and more space increase bone strengthPerches and more space increase bone strength Furnishings support some of the behavior patterns shown to be important to hensFurnishings support some of the behavior patterns shown to be important to hens Source: Manitoba Egg Farmers

3. Source: LayWel Report Enriched Cages Earliest models held small groups of hens provided nest box, perches, and box of litter for scratching and dustbathingEarliest models held small groups of hens provided nest box, perches, and box of litter for scratching and dustbathing More recent trend is to increase group size and replace nest box with curtained area and replace litter box with a mat sprinkled with feedMore recent trend is to increase group size and replace nest box with curtained area and replace litter box with a mat sprinkled with feed Source: Manitoba Egg Farmers

4. Enriched Cages Sizes of cages and colonies (Laywel 2007)Sizes of cages and colonies (Laywel 2007) –Small up to 15 hens –Medium15-30 hens –Large> 30 hens up to ~ 60 or more Larger cages provide more total space but may increase risk feather pecking, increased competition and higher mortality in larger groups (Wall 2011)Larger cages provide more total space but may increase risk feather pecking, increased competition and higher mortality in larger groups (Wall 2011) Proposed industry changes in North America include period of incremental increases in space allowanceProposed industry changes in North America include period of incremental increases in space allowance

5. Enriched Cages Sizes of cages and coloniesSizes of cages and colonies –Small up to 15 hens –Medium 15-30 hens –Large> 30 hens up to ~ 60 or more Larger cages provide more total space but may increase risk feather pecking, increased competition and higher mortality in larger groups (Wall 2011)Larger cages provide more total space but may increase risk feather pecking, increased competition and higher mortality in larger groups (Wall 2011) Proposed industry changes in Egg Bill include period of incremental increases in space allowanceProposed industry changes in Egg Bill include period of incremental increases in space allowance

6. Group Size and Space When group size increases the total area and the amount of free space increases Hens tend to synchronize activities and cluster together X 4 =

7. Objectives To determine the effects of space allowance and cage size on production, welfare and behavior measures of laying hens housed in two sizes of enriched colony cages To determine the effects of space allowance and cage size on production, welfare and behavior measures of laying hens housed in two sizes of enriched colony cages

8. 1218 Lohman Select Leghorns (LSL)-Lite Farmer Automatic ‘Enrichable’ Enriched Cage 2 x 2 factorial experiment 2 cage sizes: Large Small Large= Standard Commercial Model (358x122cm) Small= Custom built (178x122cm) 2 densities: High High= ~520 cm 2 /hen Low Low= ~748 cm 2 / hen (total floor space allowance) Methods

9. Cages were distributed between 2 rooms –3 tiers, 2 rows of cages in each room Birds were beak treated at the hatchery and reared in standard rearing cages at the research farm Housed in laying cages at 18 weeks of age Methods

10. Two Rooms Each room holds 6 “Large” and 6 “Small” Methods

11. Large Large Cage

12. Small Small Cage

13. Nesting Area

14. Scratch Area

15. 20 g feed delivered through auger 10 times per day

16. Group Sizes

17. CageFloor Space Cage Space NestScratchPerch LargeHigh 516 (80) 559 (86) 70 (11) 31 (4.8) 12 (4.5) SmallHigh 522 (81) 560 (85) 70 (11) 62.5 (9.6) 11 (4.3) LargeLow 750 (116) 814 (126) 102 (15.8) 45.5 (7) 16.8 (6.6) SmallLow 746 (115.6) 800 (124) 101 (15.6) 89.3 (13.8) 15.5 (6) Space Allowances in cm 2 (in 2 )

18. Production measures –Hen-day egg production from 20 weeks to end of lay –Egg weights and shell strength (deformation) collected from sample of eggs once per ~28 days –At 37, 43, 49, 56 and 70 weeks of age feed intake was measured over 2 day period Methods

19. Hen Day Egg Production HighLow High Density and Low Density Cages Hen Day Egg Production HighLow High Density and Low Density Cages High Density High Density = 80 in 2 /hen (93.0±.14%) Low Low Density = 116 in 2 / hen (94.4 ±.15%) Age P<0.01 Density NS

20. Feed Intake (g/bird/day)* AgeCage DensityCage Size HighLowLargeSmall Pooled SE (±) 37117.6118.8115.8120.6*4.6 43111.0110.3107.9113.3*4.2 4999.5101.599.7101.3*6.3 70109.7111.3105.6115.4*5.5 *Significantly higher feed intake in the small cages/group sizes

21. Egg Weights (g) Cage DensityCage Size Age (wks)HighLowLargeSmallPooled SE 2150.9 51.150.11.2 2957.157.557.157.4.91 3359.259.6 59.2.96 4160.360.160.2 1.07 4961.661.761.661.71.12 5762.161.862.361.7.90 6563.263.363.063.6.92 6963.663.763.6.95 No Effect of Cage Size or Density

22. (μm) Egg Deformation (μm) Cage DensityCage Size Age (wks)HighLowLargeSmallPooled SE 21 17.818.317.718.41.1 29 19.6 19.9 0.78 33 20.2 20.020.1 0.73 41 20.520.320.4 0.65 49 21.921.621.521.90.70 57 23.122.222.8 1.32 65 23.523.323.523.30.92 69 22.4 22.622.21.0 No Effect of Cage Size, Cage Density, P=.0535

23. Welfare Measures Mortality (cumulative) –cause of death determined from necropsy At 30, 50, and 60 and 70 wks of age 20% birds from each cage were sampled –Body weight –Feather condition –Cleanliness –Keel score –Foot health Methods

24. Mortality Cage DensityCage Size HighLowLargeSmallPooled SE 4.794.354.474.671.73 Cumulative % to 72 weeks of age No Effect of Cage Size or Density Significant effects of tier – birds on middle level had highest mortality (P<0.01)

25. Body Weight Cage DensityCage SizeFurnish’d Age (wks)HighLowLargeSmallPooled SE Mean 50 1715175717321733 63.3 NS 60 172217261720173275.4 NS 70 173617261719175687.3 NS Coefficient of Variation 50 9.210.99.710.5 NS 60 11.910.411.411.1 NS 70 17.117.015.220.6 NS No Effect of Cage Size or Density

26. Feather Scoring Rump Belly Back Head Neck 0 = Feathers intact 0 = Feathers intact 1 = Some feather damage 1 = Some feather damage 2 = Bare areas 2 = Bare areas

27. Feather Scoring

28. Effect of Stocking Density on Feather Scores Effect of Stocking Density on Feather Scores High Density High Density = 80 in 2 /hen Low Low Density = 116 in 2 / hen Feather score deteriorated in all birds over time (P<0.001) Feather score poorer in high density cages over time (P<0.001)

29. Effect of Stocking Density on Cleanliness Score Effect of Stocking Density on Cleanliness Score High Density High Density = 80 in 2 /hen Low Low Density = 116 in 2 / hen 0-3 increasingly dirty Cleanliness score deteriorated in all birds over time (P<0.001) Cleanliness score poorer in high density cages over time (P<0.03)

30. Behavior Nesting- enough nest space for all hens? Foraging – pecking and scratching on mat, feeder, floor Dust bathing on scratch mat or wire floors Perching Methods

31. Grad student Michelle HunnifordGrad student Michelle Hunniford Where the eggs were laidWhere the eggs were laid When the eggs were laidWhen the eggs were laid Aggression around nestingAggression around nesting Nesting

32. Location Methods: –During daily egg collection location of all eggs were recorded Scratch Area Nest Area

33. P nest = 0.925 P scratch = 0.912

34. * ** *P < 0.01 *P < 0.01 ** P < 0.001

35. Timing Methods (2 ways) 1.Digital video recording during 14 hrs of day 2.During live observations of nesting behaviour (5 -11 am) –Number of eggs recorded every 15 minutes –Analyzed for differences in location over time

38. Aggressive Behavior At 69 weeks hens were observed by systematically scanning cages 5 times during 4 observation periods in the morning from lights on to 11 am – Threats –Aggressive pecks

40. Behavior Slightly less time spent foraging in High DensitySlightly less time spent foraging in High Density No effects of density on dust bathingNo effects of density on dust bathing Majority was on wire, not scratch matMajority was on wire, not scratch mat Auger activation stimulated more foragingAuger activation stimulated more foraging Feeder chain activation stimulated dustbathing and foragingFeeder chain activation stimulated dustbathing and foraging

41. Summary No density effect on egg production, egg weights, egg shell strength, feed intakes, body weight or uniformityNo density effect on egg production, egg weights, egg shell strength, feed intakes, body weight or uniformity Higher feed intakes in groups of 28-40 compared to larger cages/group sizes of 55-80Higher feed intakes in groups of 28-40 compared to larger cages/group sizes of 55-80 No effect of size or density on total cumulative mortalityNo effect of size or density on total cumulative mortality At 60 weeks – more cracked and dirty eggs from scratch area in high density cagesAt 60 weeks – more cracked and dirty eggs from scratch area in high density cages

42. Summary Feather scores were poorer in high density cagesFeather scores were poorer in high density cages Birds were slightly dirtier in high density cagesBirds were slightly dirtier in high density cages Few effects of density on the behavior that we measuredFew effects of density on the behavior that we measured Cage/group size but not density affected nest use, timing of eggs laid and aggression around nestingCage/group size but not density affected nest use, timing of eggs laid and aggression around nesting

43. Acknowledgements Funding for this project was provided by Ontario Ministry of Agriculture, Food and Rural Affairs Egg Farmers of Canada Poultry Industry Council Clark Ag-Systems/Farmer Automatic We are grateful for the assistance of Michelle Edwards for statistical support, Arkell Poultry Research Station staff and the many, many graduates who helped with data collection