Measuring Behavior 2005: Pope et al.

The use of thermal imaging to score plumage condition in laying hens

S.J. Pope, P.H. Zimmerman, E. Glen, S. Lambton and C.J. Nicol

Department of Clinical Veterinary Science, University of Bristol, Langford, UK

This paper describes a new method of assessing the plumage condition of laying hens using thermography. The feather coverage of laying hens in commercial cage and noncage systems can decrease due to birds pecking the feathers of their companions. This can become a major welfare issue. Also, various studies have shown that the loss of feathers can lead to substantial increases in feed intake and compromise the thermo-regulatory ability of birds. Most studies of laying hen welfare therefore now include an assessment of plumage condition. At present, methods used for scoring the plumage condition of hens are primarily subjective. Birds are scored on a subjective ordinal scale for the feather condition of different parts of the body. Steps are being taken to standardise the recording system across Europe. However, the process requires that birds are caught and handled, which can be stressful and disturbing for the birds, and only a limited number of ranks (usually 4 ranging from no feathers to fully feathered) are assigned, limiting the sensitivity of the method. To overcome these problems we have investigated how the thermal output of individual birds varies with feather cover, under a range of different ambient temperatures. Using a FLIR E4 camera we have shown that the areas of a chicken’s body that have been defeathered have an increased temperature output in comparison with feathered areas. Radiometric jpeg images can be taken in situ and compared with plumage scores using conventional techniques. The method has been shown to be highly efficient and repeatable. There are also indications that it could be used to carry out large scale flock analysis to identify ‘hot spots’ of feather pecking.

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.