Development of a Scoring System to Assess Feather Damage in Canadian Laying Hen Flocks.

Feather damage (FD) due to feather pecking behavior is an ongoing welfare concern among commercial egg-laying hens. Canada's current transition from conventional cage housing to alternative housing systems, where FD can spread easily within large flocks, underlines the need for frequent and accurate assessment of plumage condition. A standardized methodology for assessing FD in Canada does not yet exist. To improve FD assessment on commercial farms, a FD scoring system and visual scoring guide for farmers were developed. Two existing plumage scoring systems, LayWel and AssureWel, which differ in level of detail and bird handling, were assessed for ease of use, and intra- and inter-observer reliability. Practical application of the AssureWel scoring system was greatest, with strong intra- and inter-observer reliability for the back region of the body (weighted kappa = 0.88 for both measures) in small-scale flocks. This informed the creation of a modified version of the AssureWel system, which included three scoring levels and the visual assessment of 50 birds per flock. An accompanying guide was developed including sampling instructions and depictions of the scoring scheme, both written and visual. This simplified scoring system can serve as a benchmarking tool for FD prevalence, and can allow for future effectiveness assessments of management strategies to prevent and control FD; however, farmers should be trained to apply this system under commercial conditions.