End of Project ReportThe objective of this study was to compare three methods of measuring body
temperature in the bovine and examine their relationship with ambient temperature.
The three methods used were (a) rumen bolus (b) tympanic logger and (c) rectal

Earley, Bernadette

Kettlewell, P.

Lowe, J.

Prendiville, Daniel J.

Spahr, C.

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1Radiotelemetry Systems for MeasuringBody TemperatureGrange Research CentreBeef Production Series No. 572End Of Project ReportProject No. 4806Radiotelemetry systems for measuring bodytemperatureAuthorsD. J. Prendiville, J. Lowe1, B. Earley, C. Spahr2and P. Kettlewell1Teagasc, Grange Research Centre, Dunsany, Co. Meath1Silsoe Research Institute, Wrest Park, Silsoe, Bedford, England2Innotek Inc. Garrett, Indiana, U.S.A.Beef Production Series No. 57Grange Research CentreDunsanyCo. MeathISBN 1 84170 297 8June 20023IntroductionRadio based signalling will play an important role in future generations for remotemonitoring of humans and many other species. Ultimately it will be possible tosample vital signs, e.g. body temperature, heart-rate and ovulation rate from animalswhatever their location, without they being aware of the procedure. The advent ofradiotelemetric techniques to continuously monitor heart-rate and blood pressure in atotally non-invasive manner, without any disturbance to the animals, should facilitatethe analytical approach of this complex and multifactorial condition.Body temperature is a good indicator of stress in all species. In poultry, for examplephysiological data can act as an immediate indicator of stress (Hamrita et al 1997,Kettlewell et al 1997). It is important that some variables be measured withoutdisturbing the natural behaviour of the animal. Many studies have been conductedusing telemetry systems to measure body temperature in bovine animals (Hahn, 1999;Lefcourt and Adams, 1998; Bergen & Kennedy, 2000; Brown-Brandl et al., 2001).Hetzel et al. (1987) measured body temperature using subcutaneous transmitters andreported that temperatures from the transmitters were 0.2oC higher than rectal. Theoverall correlation between implanted and rectal temperature was 0.96. Kort et al.(1998) had varying results using a subcutaneous transponder when compared withrectal temperature in mice. Differences between transponder transmitted and rectaltemperatures were large (P < 0.001). Hahn et al. (1990), found that rectal andtympanic temperatures were very similar (P > 0.05), but tympanic was affected byambient tempertures. Brown Brandl et al (2001) found significant differences (P <0.05) between tympanic and rectal temperatures. A number of other studies, usingheifers, observed that tympanic temperature was affected by ambient temperature(Lefcourt and Adams, 1998; Hahn et al., 1990).ObjectivesThe objective of this study was to compare three methods of measuring bodytemperature in the bovine and examine their relationship with ambient temperature.The three methods used were (a) rumen bolus (b) tympanic logger and (c) rectal.4Materials and MethodsCow TempTM rumen bolus (Figure 1) was used to monitor deep body temperaturewhich is Innotek’s patented bovine health monitoring system. It is designed tocontinuously monitor the animal’s body temperature 24 hours a day. The bolusutilises an internal battery for power and contains electronic circuitry for a low-power,low-frequency receiver; a low-power, high-frequency transmitter; a temperaturesensor; and a microprocessor to control all circuit functions and timing. The outsidediameter of the bolus measures 25 mm, the length is 95 mm and it weighs 116 grams.The system is made up of a receiver unit, and software which runs a PC to performdata processing and create graphical displays.The receiver unit has a keypad that enables the user to assign to an identification (ID)number each bolus. The user programs this ID number into the bolus using amodulated magnetic field generated by the handheld receiver unit. This programmingtechnique also allows the user to program the time interval at which the bolus willautomatically transmit. The bolus continuously transmits the animals ID numberfollowed by temperature at the programmed time interval.Figure 1. Cow TempTM rumen bolus5The system used to transmit tympanic temperature was developed by Teagasc andSilsoe Research Institute (U.K.). It comprises a sensor placed at the end of a probewhich is placed near the tympanum in the ear. The sensor transmits to a remote unitwhich is placed in the outer ear. This ‘Remote Unit’, has a number of discretesubsystems; each having it’s own on-board microcomputer responsible for handlingcommunications over the radio link power control, and configuration settings such asthe calibration of the temperature circuit (Figure 2A). The units communicate via theradio link with a ‘Base Station’ unit, which is connected to a standard serial (‘COM’)port on a standard PC. Separate analogue signal conditioning circuits provide for theamplification and conditioning of the temperature sensor signal. The Radio Moduleperforms the radio communication with the remote ‘Base Station’ (Figure 2B).Custom software on the PC, written in Visual Basic, sends commands to the BaseStation unit for onward transmission to the units, and receives data and statusinformation from the remote unit via the same route.All units operate on a single common frequency, with bidirectional radiocommunications using digital modulation techniques. Instead of transmittingcontinuously, each unit listens for a request from the Base Station (each unit havingit’s own unique address), and transmits it’s response on the common frequency onlywhen requested. This single-frequency operation greatly simplifies the overall systemdesign, and the ‘request and response’ protocol allows, in principle, any number ofunits to be used together. The digital modulation techniques allow any number ofmeasured parameters, and complex status and command information, to becommunicated with ease - the communication method is inherently extendable and‘future-proof’.6Figure 2AFigure 2BEar Tag Telemetry System - Outline DetailsA block diagram of the telemetry system is shown below:7Experimental TreatmentsBoluses (B) were inserted into the rumen in eight Charolais x steers weighing 500 kg.The animals were housed in a conventional slatted shed at a stocking density of 3 m2,and were fed silage ad libitum and 6 kg of concentrates. The recording frequency wasset at approximately 8 times every hour. Telemetry transmitters (T) were inserted intothe left ear of the same eight steers. Temperatures were recorded every minute overthe same period of five days. Rectal temperatures (R) were taken every hour over thesame period using digital thermometers (Jorgen Kruuse A/S. Model VT-801BWC LotNo 0701). Animals were not removed from their pens during the 5 day period oftemperature recording.ResultsOn days 1, 4 and 5 the B temperature measurements were significantly higher than theR or T (P ≤ 0.05) (Table 1). Over the five days the average temperatures recorded forB, R and T were 39.0, 38.4 and 38.2, respectively. There was no difference between Rand T (P > 0.05).Table 1. Mean temperature recorded by each method on days 1-5Day Bolus (B) Rectal (R ) Tympanic (T) LSD SED1 39.0a 38.6b 38.2b 0.54 0.312 39.2a 38.4ab 38.3b 0.78 0.373 39.1a 38.5ab 38.2b 0.72 0.354 38.9 a 38.0b 38.2 b 0.51 0.245 38.9 a 38.4b 38.3 b 0.42 0.20Within rows means not having a common superscript differ significantly (P ≤ 0.05).Table 2 shows the daily and overall correlation coefficients for days 1 to 5. Theoverall correlation coefficients for B and R, Band T, and R and T were 0.34, 0.65 and0.80, were respectively. The overall correlation coefficients for ambient temperaturewith B, R and T were – 0.74, – 0.54 and – 0.76, respectively. However, there wereinteractions between methods over time which indicates limitations in each method of8recording temperature. The correlation coefficient for B and R, B and T, and R withT were variable across the 5 days (Table 2).Table 2. Correlation coefficients between various temperature measurementtechniques for days 1-5 and overall (n=8 animals).MethodDay 1 2 3 4 5 Overall(d1 – d5)B/R .50 -.22 .37 -.08 .27 .34B/T .73 .65 .45 .23 .40 .65R/T .62 .00 .57 .11 .72 .80Amb/B -.63 -.29 -.41 -.36 .31 -.74Amb/R -.42 .14 .18 .17 -.40 -.54Amb/T -.40 -.62 -.01 -.45 .03 -.76Figure 3 (a) shows the temperatures of each method (B,T.R) on day 1 while Figure 3(b), 3 (c), 3 (d) and 3 (e) shows data for days 2, 3, 4 and 5, respectively for one animal(No. 296) . These figures, clearly illustrate the consistently high temperature recordedby rectal and the rumen bolus over the five day experimental period, for this particularanimal.Figure 3 (a) Bolus, rectal and tympanic temperature recordings for animal 296 onday 136.53737.53838.53939.54040.54141.51 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24HoursTemp(°C)296 1 B296 1 R296 1 T9Figure 3 (b) Bolus, rectal and tympanic temperature recordings for animal 296 onday 2Figure 3 (c) Bolus, rectal and tympanic temperature recordings for animal 296 onday 337.53838.53939.54040.54141.51 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24HoursTemp(°C)296 2 B296 2 R296 2 T3737.53838.53939.54040.54141.51 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24HoursTemp(°C)296 3 B296 3 R296 3 T10Figure 3 (d) Bolus, rectal and tympanic temperature recordings for animal 296 onday 4Figure 3 (e) Bolus, rectal and tympanic temperature recordings for animal 296 onday 536.53737.53838.53939.54040.5411 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24HoursTemp(°C)296 4 B296 4 R296 4 T37.53838.53939.54040.51 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24HoursTemp(°C)296 5 B296 5 R296 5 T11DiscussionDeep body temperature is an important index of the physiological status of an animal.Physical, chemical and in part biological processes are affected by temperature(Brody, 1945; Hales, 1984). This is the first study that compared deep body,tympanic and rectal temperatures. In the present study there was no significantdifference (P > 0.05) between tympanic and rectal. Similar results were obtained byHetzel et al. (1987). They found that temperatures transmitted from surgicallyimplanted transponders were on average 0.20C higher than rectal temperatures. Incontrast Hicks et al. (2001) found temperatures transmitted by boluses implanted inthe reticulum were similar to rectal temperatures. Brown-Brandel et al. (2001) andGoodwin, (1998), O’Brien et al. (1998) found rectal temperature was lower (P < 0.05)than deep body temperature. The results vary from different studies and there are alsodifferences between species (Goodwin, 1998). Goodwin found that, rectal andsubcutaneous temperatures in goats were significantly higher (P < 0.05) thantympanic, but rectal and subcutaneous were not different (P > 0.05). In horses andsheep rectal temperature was higher (P < 0.05) than tympanic and subcutaneous andtympanic was higher (P < 0.05) than subcutaneous temperature. Remote monitoringof temperature is feasible at long and short distances in an non-intrusive manner. Thetransmitters used in this study allowed the registering of data without handling theanimal, which could possibly have falsified the results. This makes Radiotelemetry auseful tool for recording body temperature in farm animals.ConclusionsThese data demonstrate that the rumen bolus is an effective means of continuouslymeasuring body temperature however, the efficiency of the bolus needs to beimproved. Temperature can also be logged from the tympanic membrane accurately.Securing the probe close to the tympanum for long periods cause problems that needto be resolved before the system can be used routinely.12SummaryRadiotelemetry is a powerful technology for long-term monitoring of physiologicalfunctions, such as core body temperature, in an non-invasive manner.In this study rumen boluses transmitted body temperatures from every animal everyhour of every day, up to a distance of one km.Body temperature can be logged from the ear in cattle fitted with a telemetrictympanic membrane sensor.Radiotelemetry can be used for practically all experimental conditions and fieldsituations and it will highlight animals displaying elevated temperatures, by sending amessage to a mobile phone.ImplicationsRadiotelemetry will soon allow one to phone their cow or steer for body temperature,heart-rate or blood pressure. These advances will have massive beneficialimplications for the beef and dairy industries. Oestrus detection will at last be areality in the suckler cow. Pre-determination of parturition will be common place. Itwill be possible to monitor the welfare of calves at times of stress i.e. post-partum, atweaning and castration. Also it will be possible to routinely monitor the welfare ofanimals during transport.AcknowledgementsThe authors gratefully acknowledge the technical assistance of Paddy Mallon. Manythanks are due to: the farm foreman, Gerry Santry, farm staff – Gabriel Costelloe andEddie Mulligan for their assistance throughout the experiment; to Ann Gilsenan,Bernie Leddy and Mary Weldon for typing and typesetting. Michael Nolan andTony Hegarty for statistical analyses.13ReferencesBergen, R.D. and Kennedy, A.D. (2000). Relationships between vaginal andtympanic membrane temperature in beef heifers. Canadian Journal of AnimalScience, 80: 3, 515-518.Brown-Brandl T.M., Yanagi, T., Xim, H., Gates. R.S., Bucklin, R. and Ross, G.(2001). Paper number 01-4031 2001 ASAE International meeting Sacremento,California, USA, July 30-Aug 1.Brody, S. (1945). Bioenergetics and growth. Reinhold Publ. Corp., New York, NY.Goodwin, S.D. (1998). Comparison of body temperatures of goats, horses and sheepmeasured with a tympanic inpared thermometer, an implantable microchiptransponder and rectal thermometer. “Contemporary Topics” by AmericanAssociation in Laboratory Animal Science. P51-55.Hahn, G.L. (1999). Dynamic responses of cattle to thermal heat loads. AmericanSociety of Animal Science. J. Anim. Sc. 77: Suppl 2/J Dairy Sci. 82: Suppl 2/1999.Hahn, G.L., Eigenberg, R.A., Neinaber, J.A. and Littledike, E.T. (1990). Measuringphysiological responses of animals to environmental stressors using a microcomputer-based portable datalogger. J. Anim. Sci. 68: 2658-2665.Hales, J.R.S. (1984). Thermal physiology, Raven Press, New York, NY.Hamrita, T.K., S.K. Hamrita, G. Van Wicklen, and M. Czarick, (1997). Use ofBiotelemetry in Measurement of Animal Responses to Environmental Stressors.ASAE Paper number 97-008, St. Joseph, MI.Hetzel, D.J.S., Bennett, I.L., Holmes, C.R., Encarnacae, R.O. and Mackinnon, M.J.(1987). Description and evaluation of a telemetry system for measuring bodytemperature in cattle. J. Agric. Sci. Comb. 110; 233-238.14Hicks, L.C., Hiclas, W.S., Bucklin, R.A., Shearer, J.K., Bray, D.R., Solo, P., andCorvalho, V. (2001). Comparison of methods of measuring deep body temperaturesof dairy cows. Livestock environment V1. Proceedings of the sixth internationalsymposium, May 21-23 2001. Lanisville, Kantucky edited by R. Stowell, R. Bucklierand R.W. Botcher.Kettlewell, P.J., M.A. Mitchell, and I.R. Meeks, (1997). An implantable radio-telemetry system for remote monitoring of heart rate and deep body temperature inpoultry. Computers and Electronics in Agric. 17: 161-175.Kort, Will. J., Hekking-Weizma Ineke, M., Ten Kate Marian T., Swan Vera and VonStrik Rocl. (1998). A microchip implant system as a method to determine bodytemperature of terminally ill rats and mice. Labatory-Animals- London 32 (3) 260-269.Lefcourt A.M. and Adams, W.R. (1998). Radiotelemetric measurement of bodytemperature in feedlot steers during winter. J. Anim. Sci 76: 1830-1837.Lefcourt, A.M. and Adams, W.R. (1996). Radio telemetry measurement of bodytemperatures of feedlot steers during summer. J. Anim. Sci. 74: 2633-2640.O'Brien, C., Reed, W., Hoyt, M., Buller, J., Castellani, J.W. and Young, A.J. (1998).Telemetry pill measurement of core temperature in humans during active heating andcooling. Med. Sci. Sports Exerc. 30 : (3) 468-472.

Radiotelemetry systems for measuring body temperature

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