Validation of broiler chicken gait scoring training in Thailand, Brazil and New Zealand
Broiler chickens are the most numerous terrestrial farmed animals on earth. These birds can suffer a range of pathologies which result in lameness, and one technique for assessing the impact of lameness on the individual bird, and on the flock has been gait scoring. This paper describes
a study where the results of the same training programme for validated gait scoring are compared for groups of assessors in Thailand, Brazil and New Zealand. A uniform course of training carried out in the classroom, through video assessment and through on-farm training was carried out in
the countries named; a total of 95 persons being trained overall. A measure of agreement with the reference scale for the assessors' numerical responses was carried out using a Cohen's Kappa test, and the results indicated significant differences in the 'origin position' ie the view taken
by the assessors of the impact of lameness on the bird before training had taken place, but a high degree of consistency in the response to training. The study demonstrated that gait scoring can be learned by assessors from different geographical and social backgrounds, and that the 'rate
of learning' – the improvement in performance in relation to a standard, was similar between the countries studied. The 'origin' and 'final' position of the assessors pre- and post-training, from the different countries in relation to the reference standard is discussed.