Archivos Latinoamericanos de Producción Animal. 2023. 31 (2)
Vaginally use of iButton® loggers to measure body temperature
in grazing red deer (Cervus elaphus)
Received: 20221125. Accepted: 20230501
1Corresponding author: Lorenzo Álvarez, Av. Universidad 3000 SN, Colonia UNAM CU, Delegación Coyoacán, 04510,
México D.F. Tel. 52 414 291 81 00, Fax 52 414 291 81 05
Lorenzo Álvarez Ramírez1
Abstract. When collecting accurate physiological data, it is important to eliminate human interference in situations
when it is necessary to record continuously over several days. Noninvasive methods for measuring body
temperature can be useful for monitoring health status and assessing environmental and climatic effects. The aim of
this study was to describe a) two methods for automatically recording of body temperature, by means of a vaginal
device in grazing red deer (Cervus elaphus) and b) the daily body temperature pattern. All animals were sedated
with xylazine, and had automatic thermal recording devices (iButton®, ThermochronTM, Maxim Integrated, San
Jose, CA, USA) inserted into a vaginal sponge (10 animals, 10 days) or CIDRG (13 animals, 10 days). Devices were
programmed to record temperature every 10 minutes. All devices except one corresponding to a sponge were
successfully recovered. The devices recorded a rhythmic pattern of body temperature, with the highest value
registered during the afternoon and the lowest during the morning. No major inconveniences were observed,
suggesting that the iButton® device can be successfully used in cases where records of continuous body temperature
recording are required for up to 10 days while avoiding any notable interference.
Keywords: physiological traits; heat stress; circadian rhythm; daily pattern.
Facultad de Medicina Veterinaria y Zootecnia, Universidad Nacional Autónoma de México, México.
Gabriela Arteaga Salazar2
Uso intravaginal de registradores iButton para medir la temperatura corporal en
ciervos rojos (Cervus elaphus) a pastoreo
Resumen. Para recopilar datos fisiológicos precisos, es importante eliminar la interferencia humana y tener un
registro continuo durante varios días de ser necesario. Los métodos no invasivos para medir la temperatura
corporal pueden ser útiles para monitorear el estado de salud e investigar los efectos ambientales y climáticos. El
objetivo de este estudio fue describir a) dos métodos para el registro automático de la temperatura corporal
mediante un dispositivo vaginal en ciervo rojo en pastoreo (Cervus elaphus) y b) el patrón diario de temperatura
corporal. Todos los animales fueron sedados con xilazina y se colocaron dispositivos automáticos de registro
térmico (iButton®, ThermochronTM, Maxim Integrated, San Jose, CA, USA) adheridos a una esponja vaginal (10
animales, 10 días) o CIDRG (13 animales, 10 días). Los dispositivos se programaron para registrar cada 10 minutos.
Todos los dispositivos se recuperaron con éxito con excepción de uno de los animales con esponja. Los dispositivos
registraron un patrón rítmico de la temperatura corporal, con el valor más alto durante la tarde y el más bajo
durante la mañana. No se observaron mayores inconvenientes, lo que sugiere que el dispositivo iButton® puede ser
utilizado con éxito en los casos en que se requiera un registro continuo de la temperatura corporal hasta por 10 días
sin mayores interferencias.
Palabras clave: datos fisiológicos; estrés térmico, ritmo circadiano; patrón diario.
Alejandra Sánchez Cervantes3
Uso intravaginal de registradores iButton para medir a temperatura corporal em
veadovermelho (Cervus elaphus) em pastejo
Resumo. Para coletar dados fisiológicos precisos, é importante eliminar a interferência humana para obter registros
contínuos por vários dias. Métodos não invasivos para medir a temperatura corporal podem ser úteis para
monitorar o estado de saúde e investigar os efeitos ambientais e climáticos. O objetivo deste estudo foi descrever a)
dois métodos de registro automático da temperatura corporal usando um dispositivo vaginal em veadovermelho
(Cervus elaphuse b) o padrão diário de temperatura corporal por 10 dias. Os dispositivos foram programados para
gravar a cada 10 minutos. Todos os dispositivos foram recuperados com sucesso, com exceção de um dos animais
com esponja. Os aparelhos registraram um padrão rítmico de temperatura corporal, com maior valor à tarde e
ÁlvarezRamírez et al
Materials and Methods
The study was undertaken with the approval from
the Animal Care and Use Committee of the Faculty of
Veterinary Medicine, National Autonomous University
of Mexico (protocol #028).
Location and animals
The study was carried out at a research station located
north of Mexico City (Alvarez Rarez et al., 2021) among
a captive population of noncyclic and nonpregnant
adult red deer (1.2 2.3 years of age). According to the
menor pela manhã. Não foram observadas grandes desvantagens, sugerindo que o dispositivo iButton pode ser
usado com sucesso e sem grandes interferências nos casos em que é necessário o registro contínuo da temperatura
corporal por até 10 dias.
Palavraschave: dados fisiológicos; estresse calórico, ritmo circadiano; padrão diário.
Body temperature is one of the most relevant
physiological traits of animals (Godyń et al., 2019).
Temperature values may indicate an animal's
metabolic state (Burfeind et al., 2014), presence of
infections (Lee et al., 2015; Godyń et al., 2019), or the
exposure to a challenging thermal environment
(Kinahan et al., 2007; De et al., 2017). Rectal temperature
is the most reliable indicator of core body temperature.
However, the handling practices required to
repetitively record rectal temperature may cause
serious problems, such as stressinduced hyperthermia
and possible animal welfare affectations (Hilmer et al.,
2010; Chapon et al., 2012).
Rectal and vaginal temperature have shown to be
nearly identical, and their agreement indicates that
they are interchangeable (Suthar et al., 2013; Lees et al.,
2018); differences between them are insignificant and
both values are considered reliable indicators of
physiological information (Vickers et al., 2010; Burdick
et al., 2012; Maeder et al., 2012; Suthar et al., 2013).
Recording body temperature over a prolonged period
requires the use of an automated device that once
implanted, continues to record without interrupted. A
variety of devices fulfill these requirements (Hilmer et
al., 2010; Vickers et al., 2010; Burdick et al., 2012; Maeder
et al., 2012). Automatic devices for body temperature
assessment now provide a valuable tool for researching
almost any kind of animal and its habitat (Hartman
and Oring, 2006; Hilmer et al., 2010; Signer et al., 2010;
Chapon et al., 2012; Roznik and Alford, 2012); however
specific techniques for their use must be evaluated.
The iButton® device (Thermochron, Maxim
Integrated, San Jose, CA, USA) is one of the most
popular temperature dataloggers, it records and stores
data points into an internal memory (Davidson et al.,
2003). For continuous body temperature recording,
iButton® devices can either be ingested (Kinahan et al.,
2007), surgically implanted (Taylor et al., 2004; Hilmer et
al., 2010; Lee et al., 2015) or attached to the animal's
body surface (Grayson and Dorcas, 2004; Munn et al.,
2009; Abecia et al., 2019). In cows, it has been used
subcutaneously (Lee et al., 2015) or attached to an
intravaginalintrarectal implant (Lea et al., 2008; Polsky
et al., 2017; Lees et al., 2018).
The pattern of daily body temperature is usually
defined as a circadian rhythm that extends over an
approximate 24 h period. Mean value of body
temperature (mesor), together with amplitude of the
oscillation and shape (waveform) of the rhythm are
also important factors; these parameters may have a
strong physiological significance. The rhythm reflects a
constant conflict between homeostasis and circadian
rhythmicity for control of the animal’s core
temperature, it is the result of an interplay of
mechanisms of heat production and heat loss,
controlled by the circadian system (Refinetti, 1992,
Red deer (Cervus elaphus) is a wild ruminant that has
been introduced into different regions of the globe. In
many of these regions, the species is exposed to
thermal conditions that impose a challenge and require
monitoring (Mattiello, 2009; Alvarez Ramírez et al.,
2021). In these cases, it is necessary to study body
temperature without disturbing the animal. In species
of this kind, it is not possible to record body
temperature using traditional methods, nor has an
easy, automatic method that avoids disturbing the red
deer been described. The objective of this document
was to describe a) the use of the iButton® device to
record vaginal temperature in red deer, coupled either
to a CIDR or to a polyurethane sponge, and b) assess
daily vaginal temperature pattern and its relationship
with particular environmental factors.
ISSNL 10221301. Archivos Latinoamericanos de Producción Animal. 2023. 31 (2): 187194