Validation of a pressure sensor-based system for measuring eating, rumination and drinking behaviour of dairy cattle

The main objective of our study was to validate, for dairy cows, a new pressure-based system (RumiWatch noseband sensor, Itin + Hoch GmbH, Liestal, Switzerland; RWS) that measures eating, rumination and drinking time. In experiment 1, eating, rumination and drinking time (RWS, min/h) measurements were compared with continuous behaviour recording (CR) of six dairy cows in tie-stalls (a total of 72 h). In addition, eating time measured by RWS was compared with the visiting time at automated feeders of a widely used type (Roughage Intake Control, RIC, Insentec BV, Marknesse, The Netherlands) to gain experience of the utility of RWS in a loose-housing system (experiment 2). A total of 403 h of RWS and RIC data from 18 cows was used for these two comparisons in experiment 2. In experiment 1, RWS and CR had a very dependable relationship (random coefficient regression model) for eating and rumination: eating, y = 0.98 (0.89-1.07)x + 3.25 (1.35) (the slope with the 95% confidence interval and the intercept with standard error of the mean) and rumination, y = 0.88 (0.73-1.02)x + 1.77 (1.00). The R2 values were 0.94 and 0.93, respectively, i.e. random error was small. The 95% confidence intervals of the slopes included value 1, and the intercepts did not differ from 0; i.e. there was no significant systematic error. However, experiment 2 confirmed a tendency observed in experiment 1 that RWS overestimated eating, since RWS eating time (5.1 ± 2.7 h/24 h) exceeded significantly visiting time (RIC) (3.2 ± 1.1 h/24 h; paired t-test, n = 18) in the setup where, in principle, eating was possible only in the RIC feeders. In experiment 1, the relationship between drinking time (RWS) and CR was poor: R2 = 0.20, and y = 0.49 (0.12-0.85)x + 0.64 (0.13). However, this may reflect more the challenges in measuring drinking in general than merely with RWS. In conclusion (i) the RWS results were relatively free from random errors for rumination and eating, but not for drinking, (ii) there was systematic error for eating and drinking, but not for rumination, and (iii) due to the relatively limited size of our data, further validation of RWS is recommended and RWS needs further development at least for eating and drinking measurements.