Early Detection of Respiratory Diseases in Calves by Use of an Ear-Attached Accelerometer

Abstract

Accelerometers (ACL) can identify behavioral and activity changes in calves. In the present study, we examined the association between bovine respiratory disease (BRD) and behavioral changes detected by an ear-tag based ACL system in weaned dairy calves. Accelerometer data were analyzed from 7 d before to 1 d after clinical diagnosis of BRD. All calves in the study (n = 508) were checked daily by an adapted University of Wisconsin Calf Scoring System. Calves with a score ≥ 4 and fever for at least two consecutive days were categorized as diseased (DIS). The day of clinical diagnosis of BRD was defined as d 0. The data analysis showed a significant difference in high active times between DIS and healthy control calves (CON), with CON showing more high active times on every day, except d -3. Diseased calves showed significantly more inactive times on d -4, -2, and 0, as well as longer lying times on d -5, -2, and +1. These results indicate the potential of the ACL to detect BRD prior to a clinical diagnosis in group-housed calves. Furthermore, in this study, we described the 'normal' behavior in 428 clinically healthy weaned dairy calves obtained by the ACL system.

Keywords: accelerometer; bovine respiratory disease; calf behavior; lying behavior.

Figure 1

High active, inactive, active, lying and rumination times for diseased calves (DIS = 41) and clinically healthy controls (CON = 69) from d −7 to d +1 relative to clinical diagnosis of bovine respiratory disease (BRD) (d 0). * changes between groups with a p < 0.05 based on Mann–Whitney U test. Error bars represent standard error of the mean (SEM).

Figure 2

‘Normal’ behavior examined by an ear-tag based accelerometer in 428 clinically healthy calves over one week. Mean (dark grey line) and SD (light gray areas) in minutes per hour of the parameters high active (a), inactive (b), active (c), lying (d), and rumination (e) times are presented.

Figure 3

Mean ‘normal’ behavior (dark grey line) and SD (light gray area) in 428 clinically healthy calves within one day. The parameters high active (a), inactive (b), active (c), lying (d), and rumination (e) are presented.