Animal-based measures for the assessment of welfare state of diary cattle, pigs and laying hens: Consensus of expert opinion

A Delphi technique was used to gather the opinions of animal welfare experts on the most appropriate measures for welfare assessment of farm animals. The experts were asked to consider measures that were directed towards the animal (animal-based), rather than measurement of their environment. This systematic approach was designed to achieve a degree of consensus of opinion between a large number of experts. Two rounds of postal questionnaires were targeted at people with expertise in one or more of the species of interest. The respondents suggested measures based upon observations of health status, behaviour, and examination of records. These measures reflect the animal's welfare state - in other words, how the animal is coping within the environment and husbandry system in which it lives. The measures for cattle, pigs and laying hens were categorised into 22, 23 and 28 aspects, respectively, with the highest ranking of importance being given to observation of lameness in dairy cattle and pigs and to observation of feather condition in laying hens. This Delphi study was the basis for the development of a series of protocols to assess the welfare state of dairy cattle, pigs and laying hens.