Measuring Behavior 2005: Cronin and Desnoyers

Behavior around oviposition by hens in cages with and without nest boxes

G.M. Cronin and M.A. Desnoyers

Animal Welfare Science Centre, Department of Primary Industries Victoria, Werribee, Australia

The housing of laying hens in cages is a contentious animal welfare issue. A potentially acceptable alternative to conventional laying cages is modified cages containing a nest box. However, when nest boxes are provided for hens in cages a significant proportion choose to lay on the wire cage floor outside the nest box, suggesting we lack understanding of the factors influencing nest-site selection by hens in cages.

This paper will describe a preliminary experiment conducted in an environment-controlled poultry facility to measure hen behavior in cages with and without a nest box. For the experiment 36 commercial Hyline Brown hens were housed in pairs in 2 observation cages (9 replicates of 4 hens). The pairs were selected at random from (8-bird) home cages either with or without a nest box. The observation cages were identical to the home cages, apart from the number of birds per cage. Hens were continuously video recorded using low-light, black and white video cameras and time-lapse recorders. Video recording, including inside the nest box, was assisted with the use of infra-red light. For individual hen identification under IR light, feathers on the back were marked with carbon-based black ink. Hens were allowed about 24 h habituation to the observation cages before the video data were analysed, which occurred if all 4 hens in the replicate laid on the same day. Hens were then returned to their home cages. Hen location in the observation cage, and posture and activity were continuously recorded from 2 h pre- to 2 h post-egg laying using The Observer^® Video-Pro (version 4.0 - Noldus information Technologie bv, the Netherlands). The data were iterated into 30-min periods and statistical analysis was performed using REML.

Of the 18 hens with access to a nest box, only 9 laid there; the other 9 hens laid on the wire floor of the cage. The behavior of the hens that laid in a nest box compared to on the wire cage floor will be described.

Paper presented at Measuring Behavior 2005 , 5^th International Conference on Methods and Techniques in Behavioral Research, 30 August - 2 September 2005, Wageningen, The Netherlands.