An Objective Statistical Method to Estimate Lameness Severity and Duration Based on Weight Distribution Measurements

A four-balance system for automatically measuring the load on each leg of a cow during milking in a milking robot has been developed (Pastell & Kujala 2007, Pastell 2007). It has been shown that the system can be used to detect lameness based on the weight distribution between limbs and a Probabilistic Neural Network model to detect lameness cases has been developed (Pastell & Kujala 2007). However there is a clear need to develop a model which can be used to evaluate the duration and the magnitude of the problem and adapt its behavior for individual animals.
CUSUM charts are control charts used in the quality control. They are well suited for checking a measuring system in operation for any departure from some target value. CUSUM charts are used for detecting a drift (of the level) and detecting a change of the precision of the system. In both cases the CUSUM procedure contains methods for estimating the magnitude of the shift.
This paper focuses on the use of CUSUM charts to detect ...