Table 2.

Comparison of rumination times of 10 dairy calves recorded by the RumiWatch system (RWS; ITIN + HOCH GmbH Feeding Technology, Liestal, Switzerland) and visual observations on a video

	Approach
	MF01	MF102	MF53
A) Rumination time, h/12 h
RWS	3.69 ± 0.20	2.03 ± 0.20	2.43 ± 0.20
Video	2.46 ± 0.23	2.46 ± 0.23	2.46 ± 0.23
P value4	<0.01	0.001	0.60
B) Linear regression model
Slope	0.87	0.88	0.93
95% CI range for slope	0.79–0.94	0.82–0.95	0.88–0.98
Intercept (SEM)	7.70 ± 0.64	-0.75 ± 0.57	0.73 ± 0.40
R2	0.82	0.86	0.93
P value5	<0.01	0.19	0.07

Data were processed as rumination time (min/h) in 12 one-h periods per each calf yielding a total of 120 pairs of values.

¹Model includes raw data of the RWS (no filtering).

²Model excludes rumination events lasting less than 10 min as recoded by the RWS.

³Model excludes rumination events lasting less than five min as recoded by the RWS.

⁴Comparison of rumination times determined by RWS vs. video using paired t-test.

⁵Deviation of the intercept from zero.