Lameness and pain in dairy cows

Pain associated with the injuries of hoof and surrounding tissues is an important cause of lameness. However, this condition can also be caused by non-painful changes of the locomotion system. The objective of this study was to detect the attributes of impaired gait that are associated with pain. Gait was evaluated using a subjective scoring system and objective kinematic measures, while putative pain was controlled with the known analgesic, ketoprofen. Lactating Holstein cows (n=27), diagnosed with lameness were divided into 3 groups. Each group was assigned a different dose of ketoprofen (0, 1.5, and 3.0 mg/ kg BM). The experimental period lasted 9 d and was divided into 3 phases: before, during and after treatment, each phase lasting for 3 d. During treatment cows were treated with the IV injections of assigned dose of ketoprofen. On each day of the experiment the cows' gait was recorded and video clips were analyzed using both subjective and objective methods. Subjective assessment of gait included evaluation of overall gait score and gait attributes including head bob, tracking-up, back arch and reluctance to bear weight. Kinematic measurements included stride length, maximum stride height, stride duration and hoof speed. Results of subjective gait assessment showed an improvement in overall gait score and tracking-up in cows receiving the analgesic. Kinematic analysis of gait revealed time trends for all kinematic measurements throughout the experimental period hindering the analysis of the analgesic effects. In conclusion, pain affected lameness attributes, specifically overall gait score and trackingup. Kinematic methods may provide a sensitive method of detecting other changes in gait.