Cow gait scores and kinematic gait data: can people see gait irregularities?

Abstract

Increasing lameness problems associated with intensified dairy cattle production has lead to the development of several techniques to automatically detect these problems. Comparisons of these new measuring techniques of cow locomotion with the conventional subjective observer scoring are scarce. In order to better understand human observers’ gait scoring, cows walking on a pressure-sensitive mat were evaluated for kinematic gait variables and a visual assessment of gait was also made via video recording. Forty of these videos were used for subjective gait scoring on a 3-point scale, and the observers were also asked to report any observed abnormalities (lameness indicators) that had influenced their scoring. Relationships between reported lameness indicators and subjective gait scores, between subjective gait scores and measured kinematic variables of cow locomotion and between reported lameness indicators and measured kinematic variables of cow locomotion were investigated. In general, observers based their gait score on reported indicators such as ‘tenderness’, ‘arched back’, ‘irregular gait’ and ‘increased abduction’. All of these four reported lameness indicators were correlated with measured kinematic ‘variables of asymmetry’, ‘stance time’ or both, suggesting that human observers are capable of detecting changes within these lameness indicators as measured by the pressure-sensitive mat. ‘Increased abduction’ appeared harder to detect and was reported more frequently by observers already experienced with gait scoring. Also, the measured kinematic variables of ‘stance time’ and ‘measures of asymmetry between left and right limbs’ as measured by the pressure-sensitive mat, show potential in predicting the gait score given. These reported lameness indicators and measured kinematic variables —mutually correlated and both related to the gait scores — were considered promising for subjective gait scoring in general.