A System for Identifying Lameness in Dairy Cattle

Bovine lameness caused by hoof and leg ailments is a costly problem for the dairy farmer and an important animalwelfare issue. Cow lameness necessitates medical treatment, can reduce milk production, often results in decreased bodycondition, can impair reproductive performance, and impacts animal well being. It was hypothesized that measurements ofvertical ground reaction forces as animals walk over a forceplate system could provide the basis for detecting lameness. Asystem based on this principle, designated the Reaction Force Detection (RFD) system, was developed. The system consistsof two parallel, left and right, floor plates that are each supported by four singleaxis load cells. When a cow walks throughthe system, the load cell reaction forces are recorded as electric signals that change over time. These signals are used tocalculate the magnitude and position of a single equivalent reaction force for each plate. When a single limb is on a plate,the calculated value represents the position and reaction force of that limb. Examination of calculated values over time allowsleg movement characteristics to be reconstructed, thus allowing measured reaction forces to be associated with specific limbs.Additionally, the system provides measurements of body weight and walking speed. Tests using three sound and three lamecows demonstrated that lame cows can be recognized and effected limbs can be identified.