Rearing environment and laying location affect pre-laying behaviour in enriched cages
Publication Type: |
Journal Article |
Year of Publication: |
2016 |
Authors: |
Michelle E. Hunniford, Tina M. Widowski |
Publication/Journal: |
Applied Animal Behaviour Science |
Keywords: |
laying hen, nest site selection, nesting behaviour, rearing environment |
ISBN: |
0168-1591 |
Abstract:
The number of eggs laid in a nest is often correlated with nest acceptance and therefore hen welfare. However, evaluating pre-laying behaviour may more accurately reflect welfare independent of egg location. Our objective was to compare the effect of rearing environment and laying location on the pre-laying behaviour of hens in furnished cages (FC). We hypothesized that hens reared conventionally would be less settled (more active, aggressive) during the pre-laying period than aviary-reared hens, and floor layers would be less settled than nest layers. LSL-Lite hens (n = 1080) were housed in groups of 60 (N = 12, Large FC, 41 296 cm2) and 30 (N = 12, Small FC, 20 880 cm2). Half were reared in an aviary (litter access 7 weeks) and half in standard cages. Hens were housed in FC at week 16. Each FC had a nest area (red plastic curtains, yellow plastic mesh floor); a scratch area (smooth red plastic mat); and perches that ran parallel to the feeders. Egg location on the egg belt was recorded daily from 16 to 72 weeks. Four hens/LFC and two hens/SFC were wing-tagged at 18 weeks and observed at start of lay (week 22) and peak lay (week 32). Observers continuously scored prelaying behaviour of a single hen from lights-on (05:00 h) until oviposition; behaviours performed in the final hour before oviposition were analyzed. Behavioural frequencies and durations were transformed before being analyzed with a Mixed model repeated measures ANOVA. Cage-reared hens laid more eggs in the nest (mean ± SE: 89.6 ± 0.4% vs. 81.7 ± 0.6%; P < 0.001) and fewer in the scratch (9.6 ± 0.4% vs. 17.6 ± 0.6%; P < 0.001) than aviary-reared hens. At week 22, cage-reared hens entered the nest area more often (P = 0.002) and were more active (P = 0.0007) than aviary-reared hens with no difference at week 32 (P = 0.5). Therefore, aviary-reared hens found the nest less attractive than cage-reared hens, but also expressed more settled pre-laying behaviour. Scratch layers sat for a longer duration (P = 0.0015) and more frequently (P = 0.04) than nest layers, but were also more aggressive (P = 0.001). Neither the duration nor the frequency of activity differed between nest and scratch layers. Therefore, scratch layers were not more unsettled than nest layers in the hour before oviposition. These results suggest that both rearing environment and laying location affect pre-laying behaviour in large furnished cages.