Comparison of Tympanic and Tail Temperatures in Angus and Brahman Steers

Dikmen S,Scheffler Tl,Mateescu Rg,Rodriquez E,Oltenacu Pa,Davila Kms

doi:10.16966/2576-6457.147

Abstract

In cattle, core body temperature can be used as an important indicator of heat stress level. However, accurately recording core body temperature can be difficult and labor intensive. The objectives of the current study were 1) to compare the recorded tympanic and tail body temperature measurements in steers and 2) to determine the body temperature change of Angus and Brahman steers in a hot and humid environment. Data was analyzed using a repeated measure model where repeated measures were hourly tympanic and tail temperatures and their difference for individual steers during the day of the experiment. There was a significant breed effect (P=0.01), hour (P<0.0001) and breed by hour interaction (P<0.0001) for the tympanic temperature. Brahman steers, which are known to have superior thermotolerance, maintained a lower body temperature than the Angus steers during the afternoon under grazing conditions. In the Brahman steers there was only a minimal increase in the body temperature throughout the day, an evidence of the thermotolerance ability of the breed. In the Angus steers, which experienced an increase in their body temperature from hour to hour with a peak around 1600 hour; there was a significant difference between the tympanic and tail temperature during the times when the body temperature as measured by the tympanic recordings was the highest (1300 to 1700 hour). Our results indicate that the tympanic temperature can be used to accurately and continuously monitor core body temperature in a natural environment for up to several days and without disturbing the animal.

Highlights

Body temperature can be used as an indicator of thermotolerance ability in cattle and is the most common parameter to determine cattle’s response to the environment
The environmental conditions described by hourly dry bulb temperatures (°C), relative humidity (%) and temperature-humidity index (THI) are shown in table 1
The least square means and standard errors for the tympanic and tail temperatures of Angus and Brahman steers are presented in figure 2

Summary

Introduction

Body temperature can be used as an indicator of thermotolerance ability in cattle and is the most common parameter to determine cattle’s response to the environment. These data loggers can be used vaginally to record the body temperature continuously for several days by attaching the data loggers to a blank Controlled Internal Drug Release (CIDR, Pfizer Animal Health, New York, NY). The use of data loggers intravaginally under correct conditions provides accurate continuous data of core body temperature. This type of data collection is restricted to female animals. Common locations for core body temperature in cattle are the rectum, ear canal, rumen and vagina [5]. Temperature recorded in the ear canal is a very reliable indicator of internal core body temperature because the blood flowing through the vessels of the tympanic membrane comes from the branch of the carotid artery that supplies the hypothalamus [6].

Objectives

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Results

Conclusion