Automated measurement of sheep movement order: consistent, stable and useful to identify the risk of welfare compromise?

Abstract

This pilot study investigated how the movement order of a flock of sheep in an extensive environment differed over time to determine if order, as recorded by radio frequency identification tags, was stable and if deviations in position might be used to identify animals with compromised welfare state. The hypothesis was that flock 'free' movement order would be relatively stable and repeatable. Two hundred mature Merino ewes were trained to walk a distance of 1 km following a handler carrying a bucket of grain. The sheep were allowed to move at their own pace and, provided they were not grazing, were not pushed from the rear. Thirteen runs around a fenced track occurred over an eight week period during mid-pregnancy. General health (lameness, demeanour, posture) were recorded at each run, a blood sample to assess various haematological parameters (e.g. RBC, HCT, WBC, neutrophil, lymphocyte and eosinophil concentrations) was taken from each ewe between the 12th and 13th runs and a temperament test was conducted at the completion of the runs.