Skip to main content
ARS Home » Research » Publications at this Location » Publication #74778
Title: A NONINVASIVE RADIOTELEMETRY SYSTEM TO MONITOR HEART RATE FOR ASSESSING STRESS RESPONSES OF BOVINES

Author
item LEFCOURT, ALAN - 1265-50-00
item BARFIELD, RUTH - 1265-50-00
item EREZ, BENNY - UNIVERISTY MD ELLICOTT CI
item VARNER, MARK - UNIVERITY MD COLLEGE PARK
item TASCH, URI - UNIVERSITY MD BALTIMRE CY

Submitted to: Journal of Dairy Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/16/1999
Publication Date: N/A
Citation: N/A

Interpretive Summary: Stress is an important issue in farm operations; however, determining when and how animals are stressed is often difficult. One problem is that physiological signs of stress are often evident only for very short periods of time and, consequently, are hard to detect. Heart rate generally increases with the onset of stress. We developed a radiotelemetry system to ocontinuously monitor heart rate in freely behaving cows. The transmitters are mounted externally in harnesses worn by animals. To validate the system, data were acquired over 72 h from two heifers housed in an experimental handling system. Measured heart rates increased 4.0 +/- 1.4 beat/min after cows stood, and decreased 4.8 +/- 1.0 beat/min after cows laid. The importance of social interactions as a source of stress was highlighted by agonistic encounters between the two cows. The heart rate of one of the cows increased dramatically around times of agonistic encounters. In one case, her heart rate jumped 2.6 fold prior leaving the first holding pen and remained elevated for 80 min. These results clearly show that heart rate can be used to monitor animal anxiety.

Technical Abstract: A noninvasive radiotelemetry system was developed to monitor heart rates of cows, and to view and analyze data. To validate the system, data were acquired over 72 h from two heifers housed in an experimental handling system consisting of a freestall pen, a holding pen, a milking stall, and a second holding pen. Heart rates increased 4.0 +/- 1.4 bpm after cows stood, and decreased 4.8 +/- 1.0 bpm after cows laid. For the cow naive to the experimental environment, a histogram of heart rates indexed to maximal heart rates within +/- 3 min of entry into the milking stall showed an increase from a baseline of 60 to 86 bpm, and remained elevated for 6.3 min. In contrast, heart rate of the experienced cow remained constant when she transgressed the milking stall. Around the time of an agonistic encounter: the experienced heifer remained in the freestall pen while the naive heifer, initially in the first holding pen, circled through the experimental system to obtain forage available only in the freestall pen. The encounter occurred prior to the naive animal eating; however, her heart rate jumped 2.6 fold prior leaving the first holding pen and remained elevated for 80 min. These results clearly show that heart rate can be used to monitor animal anxiety.