Defining and validating descriptors used in the Qualitative Behavioral Assessment of post-wean sows

Qualitative Behavior Assessment (QBA) can be a valuable approach in understanding farm animal welfare. It uses a holistic approach to capture an animal’s emotional state and promises improved detection of positive emotions, which sometimes can be difficult to identify using ethological-based methods. Lists of QBA descriptors validated to assess pig welfare exist, but definitions for descriptors of individual sows are not published. The objective of this study was to create and validate clear and specific definitions for a pre-existing fixed list of descriptors. A fixed list of 20 descriptors was partly modified from the EU Welfare Quality® assessment protocol for pigs to fit the context of post-weaned sows. Ten pig experts (i.e. researchers, veterinarians, technicians, farmers) were recruited to assist with defining these descriptors in a focus group-style discussion. Descriptor definitions were discussed and voted upon, with revising and re-voting as needed until an 80% agreement was reached. Half of these experts participated in a validation study. The newly developed definitions were tested by implementing QBA on a video library of post-weaned sows selected to capture a wide range of sow behavior. Principal component analysis identified two main components interpreted to represent the valence (positive or negative) and arousal (high or low) of each descriptor. Experts displayed almost perfect agreement in identifying the valence of descriptors (Kendall’s W = 0.91) and substantial agreement in the arousal (Kendall’s W = 0.66). Inter-observer reliability was also measured for each descriptor. Half of the descriptors evoked substantial agreement or better (Kendall’s W > 0.6) between the experts and only two descriptors exhibited less than moderate agreement (Kendall’s W < 0.4). These findings validate our process to delineate clear definitions for a fixed list of QBA descriptors in individual sows. This study is the first of its kind to detail the creation and validation of QBA descriptor definitions and paves the way for a more reliable use of fixed-list QBA to assess sow welfare and positive emotional states.