Research note: Age and time of day influence broiler use of platform enrichments.

Environmental enrichments have the potential to improve broiler chicken welfare. Platforms, when designed and placed effectively, can improve spatial complexity and encourage positive natural behavior. This study evaluated the spatial and temporal patterns of platform use in broilers housed with sidewall-mounted platforms compared to unenriched controls. A total of 352 male broilers were randomly assigned to one of two environmental enrichment treatments: enriched pens with white plastic slatted platforms placed along both sidewalls (Platform, n=6 pens) and unenriched controls with no platforms (Control, n=2 pens). Overhead video recordings were captured, and behavioral observations of side occupancy were conducted using instantaneous scan sampling at 15-min intervals for 24 h on d 16, 23, 30, 37, 44, and 50 of age. Birds in platform pens had greater side occupancy than controls at all ages and lighting conditions, except during the photoperiod on d 50. The most pronounced differences occurred at younger ages during the scotoperiod, with over 80% of the birds on the sides of platform pens during the scotoperiod on d 16 and 23, compared to less than 40% in control pens (P<0.0001). Less pronounced platform use patterns were observed during the photoperiod. The most significant difference in side occupancy during the photoperiod was on d 30, where 27% more birds were on the sides in platform pens compared to controls (P<0.0001). Taken together, these results suggest that even in the absence of platforms, broilers showed a preference for the sides of the pen (thigmotaxic behavior) during the scotoperiod. The presence of platforms augmented this behavior, particularly during the scotoperiod and at younger to mid-growth ages.