A practical tool for locomotion scoring in sheep: reliability when used by veterinary surgeons and sheep farmers

A four-point locomotion scoring tool for sheep was developed and tested on 10 general practice veterinary surgeons (VS) and 10 sheep farmers. Thirty-four video clips of sheep displaying different locomotion scores were recorded and randomly assorted. Following a set period of training using four other video clips typical of the four locomotion scores, participants then scored the 34 test clips. The participants repeated the training and the exercise one month later. There were high levels of intraobserver repeatability: weighted κ (κW) 0.81 for VS and 0.83 for farmers. There was no difference in intraobserver repeatability between vets and farmers (Wilcoxon signed rank P=0.8). When considering the overall distribution of scores within the video package, there were high levels of interobserver repeatability: mean κW 0.73 for VS and 0.72 for farmers. However, the repeatability for the individual locomotion scores was only fair to moderate. It is therefore recommended that when observations are repeated on different occasions they are made by the same observer.