Automatic cow lameness detection with a pressure mat: Effects of mat length and sensor resolution

- The minimum pressure mat length needed to monitor a full gait cycle is determined.
- The minimum sensor resolution of the pressure mat is determined.
- Lameness detection performance was not reduced by these sensor changes.
- Reducing the sensor price should be possible by optimization of sensor dimensions.

While previous research has shown the potential of automatic lameness detection by means of a pressure mat, these systems are currently not adopted in practice due to their high cost and low on-farm applicability. Therefore, the aim of this study was to investigate to what level the size (0.61 × 4.88 m) and resolution (0.0127 × 0.0127 m) of the pressure mat can be reduced without significant loss in lameness detection performance. To this end, standard gait variables were calculated based on adapted datasets in which the available data had been reduced to simulate the effects of a decreasing mat length and sensor resolution. These extracted gait variables were then used in a linear discriminant analysis to classify cows as non-lame, mildly lame or severely lame. This analysis indicated that the measurement zone length must be at least 3.28 m to successfully monitor one complete gait cycle, while the size of each individual sensing element should not be larger than 2.58 ∗ 10−3 m2 to avoid an increase in the misidentification of imprints. When these limits were taken into account, the obtained overall lameness detection accuracy was not worse than that of the original system.