Date of Award:

5-1992

Document Type:

Thesis

Degree Name:

Master of Science (MS)

Department:

Animal, Dairy, and Veterinary Sciences

Committee Chair(s)

Clive Arave

Committee

Clive Arave

Committee

Thomas Bunch

Abstract

Three experiments were conducted using implanted heart rate (HR) transmitters. In the first experiment three lactating Holstein cows' HR signals were monitored telemetrically for three successive days under the normal herd management. Overall mean and standard error for these cows was 76.1 ± 0.46 bpm. In the second experiment the same three cows' HR signals were monitored with a portable computer and receiver. The cows were transported 400 kilometers one way over various road surface conditions. The HR signals were monitored consecutively at the beginning of the trip and at hourly intervals during travel. The cows stayed overnight and were brought back the next day. This two-day journey was repeated one week later. As travel commenced, the cows' HRs averaged 89.7 bpm and differed significantly (p<0.01) from subsequent hourly readings. The overall mean HR of cows during the first week away trip differed significantly (p<0.005) from their HRs on all other trips. Habituation to travel occurred, as evidenced by the HR decreasing with time, on the day of travel and also from week 1 to week 2. However, the effect of road surface type on the HR was inconclusive because of partial confounding in the experimental design.

In a second experiment, two cows were exposed to five different types of aircraft noises--helicopter low altitude flyover and hover, fixed-wing low altitude flyover, jet aircraft low altitude subsonic flyover, and high altitude supersonic boom. The cows were exposed to four to five flyovers of the same type of aircraft at approximately five-minute intervals. Intervals between different aircraft type flyovers were at least one hour. Two noise disturbance experiments were conducted seven days apart. Supersonic booms and helicopter flyovers had significant effects on HR response. With increasing exposures to aircraft disturbances, there was a reduction in HR response.

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