Table 2.

Association of recovery status (recovered or relapsed) with relative changes in feeding and activity behaviors of dairy calves (n = 19 matched pairs^a) in the 10 days after initial Bovine Respiratory Disease diagnosis and antimicrobial therapy on d 0.

Variable	Recovered	Relapsed	SEM	F-valued	P-value (recovery status)c	P-value (recovery status * day)
Relative change milk intake %	96.66	101.13	3.01	1.001,17	0.33	0.91
Relative change drinking speed %	114.24	89.96	5.11	10.181,16	0.01	0.22
Relative change rewarded visits %	105.58	110.07	4.24	0.501,16	0.49	0.17
Relative change unrewarded visits %	105.31	103.27	1.95	0.541,18	0.47	0.62
Relative change starter intake %	125.81	104.70	4.34	10.441,17	0.01	0.32
Relative change lying time %	95.48	98.81	0.90	6.701,17	0.01	0.05
Relative change lying bouts %	112.28	107.04	3.18	1.321,17	0.27	0.20
Relative change step count %	229.81	185.96	27.61	1.241,18	0.28	0.01
Relative change acceleration activity indexd %	216.36	168.11	22.38	2.281,18	0.15	0.01

Relative changes referred to day 0 as a baseline. Feeding behaviors (average drinking speed, milk intake, and number of rewarded visits) were recorded by an automated milk feeder from calves offered 10 L of milk replacer/day, and activity measures (lying time, step count, acceleration activity index^b and lying bouts) were recorded by a pedometer. Results are reported as least squares means^c.

^aAll calves were pair matched to healthy calves by age at diagnosis, birthdate, and gender. Bovine Respiratory Disease was defined as a clinical score of at least 5²⁶ and lobar lung consolidation²⁷.

^bThe acceleration activity index was generated by the commercial software algorithm (IceRobotics, Scotland) based on a calf’s daily average acceleration rate and step count.

^cSignificance are in bold P < 0.05.

^dSuperscripts refer to numerator and denominator degrees of freedom.