By Josiah Mullet-Koop
Perching is a highly motivated behaviour for laying hens and improves their welfare in commercial environments. Early life experience with perches is important for learning and cognitive development, but little is known about perching behaviour during rearing. The objective of this study was to strengthen our understanding of perch use during rearing by observing how pullets behaved under typical commercial management. To test this, an observational study was conducted in a commercial pullet barn housing 11,200 DeKalb White pullets in a 2-tier housing system with 56 sections. Each section contained four perches, a feed perch (FP), a Waterline Perch (WP), a Platform Perch (PP) and a High Perch (HP), each at different elevations within the section. Video was collected from n=16 sections that were selected evenly through the barn. The study was split into two periods to account for a change in system design as the pullets aged: a Closed Period (CP), during weeks 1-3 and an Open Period (OP), during weeks 5-16. Scan sampling from video images was done to count the number of pullets perching at 15-min intervals during the light and 30-min intervals during the dark throughout the CP, while 30-min and 2-h intervals were used for the light and dark, respectively, during the OP. Proc Glimmix was used in SAS Studio to analyze the data. Perching was first observed at about four days of age. During the CP, there was no effect of light period, except for the use of the feed perch which was used more during the dark than the light (F=4.79,df=3,1003,p<0.0001). During the OP, we found that pullets perched more at night than during the day (F=100.32,df=1,7,p<0.0001). This knowledge of use of different perches in a commercial rearing aviary can inform guidelines on perch requirements to improve the welfare of laying hens.
