Assessing the Validity of Animal-Based Indicators of Sheep Health and Welfare: Do Observers Agree?

Sixteen animal-based indicators of sheep welfare, previously selected by a stakeholder panel, and based on the Farm Animal Welfare Council (FAWC) Five Freedoms, were assessed in terms of the level of inter-observer agreement achieved during on-farm testing. Eight observers independently tested the 16 indicators on 1158 sheep from 38 farms in England and Wales. Overall inter-observer agreement was evaluated by Fleiss’s kappa (κ), and the pair-wise agreement of each observer was compared to a ‘test standard’ observer (TSO). Inter-observer assessments of the welfare indicators; dental abnormality, cleanliness score (ventral abdomen), mastitis, tail length, skin lesions, body condition scoring and lameness produced ‘fair to good’ levels of agreement (0.40 < κ < 0.75) and joint swellings had ‘excellent’ levels of agreement (κ ≥ 0.75). The very low apparent prevalence (