A Review of Methods to Measure Animal Body Temperature in Precision Farming
---
paper_title: Effect of temperature level on thermal acclimation in Large White growing pigs.

paper_content:

The effect of temperature level (24°C, 28°C, 32°C or 36°C) on performance and thermoregulatory response in growing pigs during acclimation to high ambient temperature was studied on a total of 96 Large White barrows. Pigs were exposed to 24°C for 10 days (days −10 to −1, P0) and thereafter to a constant temperature of 24°C, 28°C, 32°C or 36°C for 20 days. Pigs were housed in individual metal slatted pens, allowing a separate collection of faeces and urine and given ad libitum access to feed. Rectal (RT) and cutaneous (CT) temperatures and respiration rate (RR) were measured three times daily (0700, 1200 and 1800 h) every 2 to 3 days during the experiment. From day 1 to 20, the effect of temperature on average daily feed intake (ADFI) and BW gain (average daily gain, ADG) was curvilinear. The decrease of ADFI averaged 90 g/day per °C between 24°C and 32°C and 128 g/day per °C between 32°C and 36°C. The corresponding values for ADG were 50 and 72 g/day per °C, respectively. The 20 days exposure to the experimental temperature was divided in two sub-periods (P1 and P2, from day 1 to 10 and from day 11 to 20, respectively). ADFI was not affected by duration of high-temperature exposure (i.e. P2 v . P1). The ADG was not influenced by the duration of exposure at 24°C and 28°C groups. However, ADG was higher at P2 than at P1 and this effect was temperature dependent (+130 and +458 g/day at 32°C and 36°C, respectively). In P2 at 36°C, dry matter digestibility significantly increased (+2.1%, P P
---
paper_title: Comparison of reticular and rectal core body temperatures in lactating dairy cows.

paper_content:

The Phase IV Cattle Temperature Monitoring System (CTMS; Phase IV Engineering Inc., Boulder, CO) marketed by MaGiiX (MaGiiX Inc., Post Falls, ID) uses a passive bolus equipped with a temperature sensor, a panel reader placed at a parlor entrance or exit to query the bolus, and a software package to collect, analyze, and view data. The biologically inert bolus resides in the cow's reticulum and is queried each time the cow passes the reader. Reticular temperature (RETT) and rectal temperature (RECT) were recorded simultaneously in the milking parlor exit lane in 4 consecutive milkings in each of 4 seasons, totaling 16 measurements per cow. The RETT were obtained by using the phase IV CTMS, whereas the RECT were obtained manually with a GLA M750 thermometer (GLA Agricultural Electronics, San Luis Obispo, CA). Data were edited to remove RETT likely to have been affected by a recent drinking bout. For the 2,042 observations used in analyses, means (+/-SD) were 39.28 (+/-0.41), 38.83 (+/-0.36), and 0.45 (+/-0.33) for RETT, RECT, and the difference between RETT and RECT, respectively. The RETT and RECT were strongly correlated (r = 0.645). The relationship between RETT and RECT varied by season, milking, housing system, and parity. Because dairy producers and veterinarians are accustomed to viewing rectal temperatures, equations to adjust reticular temperatures to a rectal-based scale may increase the utility of the phase IV CTMS. The resulting conversion equations were RECT = 19.23 + 0.496(RETT) for the a.m. milking and RECT = 15.88 + 0.587(RETT) for the p.m. milking.
---
paper_title: Detection of foot-and-mouth disease virus infected cattle using infrared thermography

paper_content:

In this study, infrared thermography (IRT) was assessed as a means of detecting foot-and-mouth disease virus (FMDV)-infected cattle before and after the development of clinical signs. Preliminary IRT imaging demonstrated that foot temperatures increased in FMDV-infected animals. The maximum foot temperatures of healthy (n=53), directly inoculated (DI) (n=12), contact (CT) (n=6), and vaccine trial (VT) (n=21) cattle were measured over the course of FMD infection. A cut-off value was established at 34.4 degrees C (sensitivity=61.1%, specificity=87.7%) with the aim of detecting FMDV-infected animals both before and after clinical signs were observed. Seven of 12 (58%) DI and 3/6 (50%) CT animals showed maximum foot temperatures exceeding the 34.4 degrees C cut-off before the development of foot vesicles. In contrast, only 5/21 (24%) VT animals displayed pre-clinical foot temperatures above this cut-off possibly indicating partial vaccine protection of this group. These results show IRT as a promising screening technology to quickly identify potentially infected animals for confirmatory diagnostic testing during FMD outbreaks. Further evaluation of this technology is needed to determine the value of IRT in detecting animals with mild clinical signs or sub-clinical infections.
---
paper_title: The non-invasive and automated detection of bovine respiratory disease onset in receiver calves using infrared thermography

paper_content:

Bovine respiratory disease complex (BRD) causes considerable economic loss and biosecurity cost to the beef industry globally and also results in significant degradation to the welfare of affected animals. The successful treatment of this disease depends on the early, timely and cost effective identification of affected animals. The objective of the present study was to investigate the use of an automated, RFID driven, noninvasive infrared thermography technology to determine BRD in cattle. Sixty-five calves averaging 220 kg were exposed to standard industry practices of transport and auction. The animals were monitored for BRD using conventional biometric signs for clinical scores, core temperatures, haematology, serum cortisol and infrared thermal values over 3 weeks. The data collected demonstrated that true positive animals for BRD based on a gold standard including core temperature, clinical score, white blood cell number and neutrophil/lymphocyte ratio displayed higher peak infrared thermal values of 35.7 ± 0.35 °C compared to true negative animals 34.9 ± 0.22 °C (P < 0.01). The study also demonstrated that such biometric data can be non-invasively and automatically collected based on a system developed around the animal’s water station. It is concluded that the deployment of such systems in the cattle industry would aid animal managers and practitioners in the identification and management of BRD in cattle populations.
---
paper_title: Daily variation in the udder surface temperature of dairy cows measured by infrared thermography: Potential for mastitis detection

paper_content:

The daily and within-day variation in udder temperature was monitored in dairy cows (n = 10) using infrared thermography (IRT). The initial assessment and prediction of udder surface temperature variation would hopefully form the basis for future development of an early detection method for mastitis. Our initial objective was to determine the magnitude and pattern of udder temperature variation. To accomplish this, we measured daily fluctuations in udder temperature and the influence of environmental factors upon these values in non-mastitic cows. Udder temperature rose significantly after an exercise period (P < 0.05). Within-day monitoring of udder temperature demonstrated there was a distinct circadian rhythm. Lag regression analysis showed that previous daily udder temperatures together with environmental temperature parameters could successfully predict current udder temperature with a high degree of accuracy. The variation between predicted and actual udder temperature was within the detectable rang...
---
paper_title: Implications of changes in core body temperature.

paper_content:

Dairy farmers and veterinarians have used body temperatures, most commonly rectal temperatures, to detect and manage febrile disease and changes in the state of cows (estrus and onset of calving) for many years. Mastitis, pneumonia, metritis, lameness, estrus, onset of parturition, heat stress, and subacute ruminal acidosis (SARA) are among the physiological conditions potentially correlated with body temperature that deviates from normal. Many new technologies have been introduced to measure body temperature of cattle at various locations, including rectum, ear (tympanic), vagina, reticulum-rumen, skin, and milk. While each location has its own advantages and disadvantages, temperature measurements at some of these locations can be automated for routine, frequent, and non-disruptive temperature recording. Systems for measurement of reticular temperature are available commercially. However, many factors other than the physiological conditions of interest affect reticular temperature. Among these are ambient temperature, food and water consumption, stage of lactation cycle, age, recumbency, activity level, stage of gestation, and of course, general health. The relationship between reticular and rectal temperatures appears to be relatively consistent, though the correlation is affected by time of season, housing system, and time of day. Reticular temperatures are affected by water intake, and substantially so for large volumes and extremely cold water; and dips in reticular temperature following water consumption must be considered when interpreting observations. Research is continuing to assess the ability of reticular temperature monitoring, perhaps in conjunction with other precision dairy farming tools, to allow earlier intervention with appropriate management. Success of early intervention will be the key to the ultimate success of any temperature monitoring technology.
---
paper_title: A study on the applicability of implantable microchip transponders for body temperature measurements in pigs

paper_content:

Background: The applicability of an electronic monitoring system using microchip transponders for measurement of body temperatures was tested in 6-week-old conventional Danish weaners infected with classical swine fever virus (CSFV). Subcutaneous tissue temperatures obtained by the implantable transponders were compared with rectal temperatures, recorded by a conventional digital thermometer. Methods: In a preliminary study, transponders were inserted subcutaneously at 6 different positions of the body of 5 pigs. The transponders positioned by the ear base provided the best correlation to rectal temperature. To test the stability of the monitoring system in a larger group of pigs, transponders were therefore inserted by the left ear base in a subsequent infection experiment with 30 pigs. Results: Generally, the microchip transponders measured a subcutaneous tissue temperature, which was about 1°C lower than the rectal temperature. However, a simple linear relationship between the measures of the two methods was found. Conclusions: Our study showed that the tested body monitoring system may represent a promising tool to obtain an approximate correlate of body temperatures in groups of pigs. In contrast, however, the tested system did not constitute a suitable tool to measure body temperatures of individual animals in the present pig infection experiment.
---
paper_title: Estimating metabolic heat loss in birds and mammals by combining infrared thermography with biophysical modelling.

paper_content:

Infrared thermography (IRT) is a technique that determines surface temperature based on physical laws of radiative transfer. Thermal imaging cameras have been used since the 1960s to determine the surface temperature patterns of a wide range of birds and mammals and how species regulate their surface temperature in response to different environmental conditions. As a large proportion of metabolic energy is transferred from the body to the environment as heat, biophysical models have been formulated to determine metabolic heat loss. These models are based on heat transfer equations for radiation, convection, conduction and evaporation and therefore surface temperature recorded by IRT can be used to calculate heat loss from different body regions. This approach has successfully demonstrated that in birds and mammals heat loss is regulated from poorly insulated regions of the body which are seen to be thermal windows for the dissipation of body heat. Rather than absolute measurement of metabolic heat loss, IRT and biophysical models have been most useful in estimating the relative heat loss from different body regions. Further calibration studies will improve the accuracy of models but the strength of this approach is that it is a non-invasive method of measuring the relative energy cost of an animal in response to different environments, behaviours and physiological states. It is likely that the increasing availability and portability of thermal imaging systems will lead to many new insights into the thermal physiology of endotherms.
---
paper_title: Noninvasive assessment of autonomic activity for evaluation of pain in calves, using surgical castration as a model

paper_content:

The role of the autonomic nervous system (ANS) in mediating eye temperature responses during painful procedures was examined in thirty 4-mo-old bull calves randomly assigned to 4 treatments: 1) sham handling control (C; n = 8), 2) surgical castration (SC; n = 6), 3) local anesthesia with sham handling (LAC; n = 8), and 4) local anesthesia with surgical castration (LASC; n = 8). Maximum eye temperature (°C), measured by infrared thermography, heart rate (HR), and heart rate variability (HRV) were recorded continuously from 25 min before to 20 min after castration. The HRV was analyzed by examining segments of 512 interbeat intervals before and after treatments and comparing the root mean square of successive differences (RMSSD), high and low frequency (HF and LF, respectively) power, and the ratio of LF and HF powers (LF:HF). Jugular blood samples were analyzed for norepinephrine and epinephrine in C and SC treatments and for cortisol during all treatments. There was an immediate increase in HR following castration in SC (+15.3 ± 2.8 beats/min) and LASC (+6.3 ± 2.4 beats/min) calves. Eye temperature increased during the 20-min observation period in SC and LASC calves (+0.47 ± 0.05°C and +0.28 ± 0.05°C, respectively), and there was a small increase in C calves (+0.10 ± 0.05°C). Following castration in SC calves, there was an increase in RMSSD (+25.8 ± 6.4) and HF power (+11.0 ± 6.5) and LF:HF decreased (−2.1 ± 0.7). Following castration in LASC, there was an increase in RMSSD (+18.1 ± 4.9) and a decrease in LF power (−10.2 ± 5.0). Cortisol increased above baseline within 15 min following treatment in both castrated groups, but was greater for SC calves (+18.4 ± 2.3 ng/mL) than for LASC calves (+11.1 ± 1.9 ng/mL). After castration, norepinephrine increased 3-fold and epinephrine increased by half in SC calves but not in C calves. There were no changes in HR, HRV, or cortisol responses to C or LAC treatments. Local anesthetic reduced, but did not eliminate, responses to surgical castration. The synchronized increase in catecholamine and HR responses immediately following SC treatment suggests the initial response was mediated by the sympathetic branch of the ANS. The subsequent changes in RMSSD, HF power, and LF:HF ratio indicated this was followed by an increase in parasympathetic activity. The use of HR, HRV, and infrared thermography measurements together provide a noninvasive means to assess ANS responses as indicators of acute pain in cattle.
---
paper_title: Effects on fetal and maternal body temperatures of exposure of pregnant ewes to heat, cold, and exercise

paper_content:

We exposed Dorper-cross ewes at ∼120–135 days of gestation to a hot (40°C, 60% relative humidity) and a cold (4°C, 90% relative humidity) environment and to treadmill exercise (2.1 km/h, 5° gradien...
---
paper_title: Thermographic Evaluation of the Lower Critical Temperature in Weanling Horses

paper_content:

Accommodating weanling horses in loose housing (sleeping hall with deep-litter bed and paddock) environments in winter at northern latitudes exposes the nonhuman animals to low ambient temperatures. We determined the heat loss of nine weanling horses in a cold environment by infrared thermography to assess their thermoregulatory capacity. The rate of heat loss was 73.5 to 98.7 W/m2 from the neck and 69.9 to 94.3 W/m2 from the trunk. The heat loss was higher at -16 °C than at 0 °C and -9 °C (p ≤ .01), indicating that the lower critical temperature may have been between -9 °C and -16 °C. Surprisingly, the heat loss from the trunk was less at -23 °C than -16 °C (p < .05). The frost on the surface of the hair coat at -23 °C probably disturbed the thermographic examination. Thus, thermography is not necessarily suitable for determining heat loss at very cold temperatures. Our results emphasize the importance of taking the housing temperature into account in planning the feeding of cold-housed weanling horses i...
---
paper_title: Relationship of ruminal temperature with parturition and estrus of beef cows

paper_content:

Spring-calving Angus cows (n = 30) were used to evaluate changes in ruminal temperature (RuT) related to parturition and estrus. Cows were synchronized and artificially inseminated with semen from a single sire. Temperature boluses were placed in the rumen at 7.0 ± 0.2 mo of gestation. Boluses were programmed to transmit RuT every 15 min. Cows (BW = 623 ± 44 kg, BCS = 4.9 ± 0.4) calved during 3 wk, and estrus was synchronized at 77 ± 7 d after calving with PGF(2α). Cows were observed every 12 h to detect estrus. Daily average ambient temperatures ranged from 2 to 22 °C during parturition (February to March) and 17 to 25 °C during estrus (May to June). Ruminal temperature from 7 d before to 3 d after parturition and 2 d before to 2 d after visual detection of estrus was analyzed using the MIXED procedure. Ruminal temperatures <37.72 °C were attributed to water consumption and excluded from analyses. Day did not influence (P = 0.36) RuT from d -2 to -7 before parturition (38.94 ± 0.05 °C). Ruminal temperature decreased (P < 0.001) from d -2 to d -1 before parturition (38.88 ± 0.05 to 38.55 ± 0.05 °C, respectively). Ruminal temperature was not influenced (P = 0.23) by day from 1 d before to 3 d after parturition (38.49 ± 0.05 °C). Ruminal temperature at 0 to 8 h after detection of estrus (38.98 ± 0.09 °C) was greater (P < 0.001) compared with RuT at the same daily hour of the day before (38.37 ± 0.11 °C) or the day after estrus (38.30 ± 0.09 °C). Ambient temperature did not influence (P > 0.30) RuT at parturition or estrus. Ruminal temperature decreased the day before parturition and increased at estrus in spring-calving beef cows and has potential use as a predictor of parturition and estrus.
---
paper_title: Insights into animal temperature adaptations revealed through thermal imaging

paper_content:

AbstractInfrared thermal technology allows for the real-time visualisation of fixed or transient changes in the long-wave radiative energy emanating from an object, in essence, allowing for the estimation of surface temperature. Animal surface temperatures are, therefore, readily detected using this technology, allowing for the assessment of physiological responses associated with the regulation of body temperature. In this paper, we will introduce some recent advances made possible or enhanced through the use of thermal imaging. In particular, this imaging technology has shed light on the regulation of peripheral blood flow in endothermic animals, on the dynamics of animal heat transfer in complex thermal environments, on the production of heat associated with metabolism and on the importance of evaporative heat loss to respiratory function and its potential contribution to preventing overheating of the brain. More than a simple imager for temperature, this technology has the potential to contribute a gr...
---
paper_title: Use of thermography to screen for subclinical bumblefoot in poultry

paper_content:

Thermographic imaging is a noninvasive diagnostic tool used to document the inflammatory process in many species and may be useful in the de- tection of subclinical bumblefoot and other inflamma- tory diseases. Bumblefoot is a chronic inflammation of the plantar metatarsal or digital pads of the foot (pododermatitis), or both. It is one of the major health problems in birds including chickens and is responsible for significant economic losses in commercial poultry operations. Early diagnosis of bumblefoot is essential for the prevention of economical loss and the improve- ment of animal well-being. The object of this study was to determine the suitability of thermography for the identification of subclinical bumblefoot in chickens. Ex- periment 1 was designed to validate thermography as a tool for screening avian populations for bumblefoot. The plantar surface of the feet of 150 randomly selected hens was imaged using a thermal camera. The thermal images were identified as suspect, positive, or negative for bumblefoot based on thermal patterns of the plan- tar surface. Visual inspection of the feet identified as suspect followed 14 d later. A visual score of clinical, mildly clinical, or negative for bumblefoot was assigned, based on gross pathological changes in the plantar sur- face. A correlation between initial thermal images iden- tified as suspect for bumblefoot and a visual score of positive 14 d later was 83% (P < 0.01). In experiment 2, hens whose feet were free of lesions were inoculated in the metatarsal foot pad with Staphylococcus aureus. Thermal images and visual clinical scores were taken, prechallenge and 1, 2, 3, 4, and 7 d postchallenge. The correlation between thermal images classified as clini- cal and a visual score of clinical for bumblefoot was 86.7% (P < 0.001). However, the correlation between the thermal images classified as mild (subclinical) and a visual score of mild was only 26.7%, suggesting that thermography is a more sensitive indicator of subclini- cal infection than visual appraisal. Thermography may thus provide a useful tool for screening avian popula- tions for signs of bumblefoot, early in the course of the disease, which will improve recovery percentages and bird well-being.
---
paper_title: Applications of thermal imaging in avian science

paper_content:

Thermal imaging, or infrared thermography, has been used in avian science since the 1960s. More than 30 species of birds, ranging in size from passerines to ratites, have been studied using this technology. The main strength of this technique is that it is a non-invasive and non-contact method of measuring surface temperature. Its limitations and measurement errors are well understood and suitable protocols have been developed for a variety of experimental settings. Thermal imaging has been used most successfully for research on the thermal physiology of captive species, including poultry. In comparison with work on mammals, thermal imaging has been less used for population counts, other than for some large bird species. However, more recently it has shown greater success for detection of flight paths and migration. The increasing availability and reduced cost of thermal imaging systems is likely to lead to further application of this technology in studies of avian welfare, disease monitoring, energetics, behaviour and population monitoring.
---
paper_title: Effect of temperature on thermal acclimation in growing pigs estimated using a nonlinear function.

paper_content:

Ninety-six Large White growing barrows were used to determine the effect of temperature on thermoregulatory responses during acclimation to increased ambient temperature. Pigs were exposed to 24°C for 10 d and thereafter to a constant temperature of 24, 28, 32, or 36°C for 20 d. The study was conducted in a climate-controlled room at the INRA experimental facilities in Guadeloupe, French West Indies. Relative humidity was kept constant at 80% throughout the experimental period. Rectal temperature, cutaneous temperature, and respiratory rate were measured [breaths per minute (bpm)] 3 times daily (0700, 1200, and 1800 h) every 2 or 3 d during the experiment. The thermal circulation index (TCI) was determined from rectal, cutaneous, and ambient temperature measurements. Changes in rectal temperature, respiratory rate, TCI, and ADFI over the duration of exposure to hot temperatures were modeled using nonlinear responses curves. Within 1 h of exposure to increased temperature, rectal temperature and respiratory rate increased by 0.46°C/d and +29.3 bpm/d, respectively, and ADFI and TCI decreased linearly by 44.7 g•d(-2)•kg(-0.60) and 1.32°C/d, respectively until a first breakpoint time (td(1)). This point marked the end of the short-term heat acclimation phase and the beginning of the long-term heat acclimation period. The td(1) value for ADFI was greater at 28°C than at 32 and 36°C (2.33 vs. 0.31 and 0.26 d, respectively, P < 0.05), whereas td(1) for the TCI increase was greater at 36°C than at 28 and 32°C (1.02 vs. 0.78 and 0.67 d, respectively; P < 0.05). For rectal temperature and respiratory rate responses, td(1) was not influenced by temperature (P > 0.05) and averaged 1.1 and 0.89 d, respectively. For respiratory rate and rectal temperature, the long-term heat acclimation period was divided in 2 phases, with a rapid decline for both variables followed by a slight decrease (P < 0.05). These 2 phases were separated by a second threshold day (td(2)). For rectal temperature, td(2) increased significantly with temperature (1.60 vs. 5.16 d from 28 to 36°C; P < 0.05). After td(2), the decline in rectal temperature during the exposure to thermal challenge was not influenced by temperature, suggesting that the magnitude of heat stress would affect thermoregulatory responses only at the beginning of the long-term heat acclimation period. The inclusion of random effects in the nonlinear model showed that whatever the temperature considered, interindividual variability of thermoregulatory responses would exist.
---
paper_title: Peripheral temperature drop in response to anticipation and consumption of a signaled palatable reward in laying hens (Gallus domesticus)

paper_content:

Abstract The present study describes effects of anticipation and consumption of a palatable reward on comb surface temperature. The purpose was to investigate temperature responses as a potential physiological indicator of positive emotional states in laying hens. A rise in body temperature in response to stimuli predictive of or during exposure to unpleasant events has been interpreted as evidence of emotions in mammals and avians. However, this phenomenon has so far only been studied during anticipation of or exposure to negative events; i.e. emotions of a negative valence. Infrared thermography was used to record potential alterations in comb surface temperature to a conditioned cue signaling a reward (mealworms) and during reward delivery. On average, comb temperature dropped 1.5 °C (95% CI: +/− 1.2 °C) after exposure to CS and consumption of reward (p ~ 0.0014) when initial comb temperature was above 30 °C. Such temperature drop indicates a peripheral vasoconstriction and has clear resemblances to emotional fever as seen during negative emotional states. Thus, we propose that a drop in peripheral temperature reflects emotional arousal more than emotional valence. Substantial temperature responses due to diet-induced thermogenesis were found, further emphasizing a cautious interpretation of altered comb temperature in studies of animal welfare.
---
paper_title: Feto-Maternal Relationships in Goats During Heat and Cold Exposure

paper_content:

Maternal and fetal body temperatures were measured in five Boer goats, of mean mass 64 +/- 8 kg, using temperature-sensitive radiotelemeters implanted intra-abdominally. Body temperatures were recorded every 5 min. Throughout the last month of gestation, fetal temperature was approximately 0.6 (o)C higher than that of the mother, in normal laboratory conditions (ambient air temperature: 21-24 (o)C). This feto-maternal temperature difference between the goat fetus and its mother is similar to that found in other mammals, including sheep. When the pregnant goats were subjected to short-term heating and cooling, the difference between maternal and fetal body temperatures changed. Thus the mean difference between fetal and maternal body temperatures decreased from 0.4 to 0.2 (o)C during 2 h of heating, while it widened from 0.3 to 0.7 (o)C during 6 h of cooling. These data support the idea that the fetus is thermally protected from excursions of body temperature during changes in the mother's thermal environment. Reports of goat stock losses and abortions during cold spells in their natural habitats may be the result of more severe and/or prolonged cold exposures that not only adversely affect fetal or maternal body temperature, but also influence other aspects of metabolism. Experimental Physiology (2001) 86.2, 199-204.
---
paper_title: Eye temperature and heart rate variability of calves disbudded with or without local anaesthetic

paper_content:

The possibility that pain can be detected from changes in eye temperature and heart rate variability (HRV) during disbudding was examined in thirty calves, randomly assigned to four treatments: 1) sham handling (control), 2) local anaesthetic (LA, cornual nerve injection) and sham disbudded, 3) sham LA and disbudded, 4) LA and disbudded. During a 40 min sampling period, maximum eye temperature, behavior and HRV parameters were recorded continuously. One week later, twelve disbudded calves were injected with adrenocorticotrophic hormone (ACTH) or saline and maximum eye temperature was recorded. There was a rapid drop in eye temperature during the 5 min following disbudding without LA (P < 0.05). Eye temperature then increased and was higher than baseline over the remaining sampling period following both disbudding procedures (P < 0.001), a response which could not be explained by increased physical activity LA increased eye temperature prior to disbudding (P < 0.001). Heart rate increased (P < 0.001) during the 5 min following disbudding with and without LA, however, LF/HF ratio only increased during this time (P < 0.01) following disbudding without LA. Eye temperature did not change following ACTH, suggesting that hypothalamus–pituitary–adrenal axis (HPA) activity is not responsible for the changes in eye temperature following disbudding. The increase in LF/HF ratio following disbudding without LA suggests an acute sympathetic response to pain, which could be responsible for the drop in eye temperature via vasoconstriction. HRV and eye temperature together may be a useful non-invasive and more immediate index of pain than HPA activity alone.
---
paper_title: Scaling the daily oscillations of breathing frequency and skin temperature in mammals.

paper_content:

Among mammals, the peak-trough difference (PTD) of the circadian pattern of body temperature (T(b)) drops very little with the increase in body mass (W), despite the large increase in heat capacitance and thermal inertia. We asked whether this might be contributed by systematic differences in the circadian pattern of breathing frequency (f) and skin temperature (Tskin), which are parts of the control mechanisms of heat loss. Measurements had been conducted on animals of eight species, chosen to cover a four-fold range in W, while resting and awake. The oscillation of f preceded that of T(b) in 7 of the 8 species, and its acrophase did not correlate with W. The daily mean and PTD of f scaled with W in a similar manner (respectively, W(-)(23) and W(-)(0.29)), the PTD averaging about 20% of the daily mean. The circadian oscillations of Tskin, measured in specimens of five species at three locations (abdomen, ear and thigh), were in phase with T(b). Neither the PTD nor the acrophase of Tskin changed systematically with W. The differences between T(b) and Tskin (means, peaks and troughs) decreased significantly with W; on average, the T(b)-Tskin difference scaled to W(-)(0.19). In conclusion, the relative amplitudes and the acrophase of Tskin and f did not show systematic inter-species differences. The progressive increase of Tskin with W could be a factor in maintaining the PTD of T(b) within a narrow range among mammals of very different size.
---
paper_title: Genotype effects on body temperature in dairy cows under grazing conditions in a hot climate including evidence for heterosis.

paper_content:

We compared diurnal patterns of vaginal temperature in lactating cows under grazing conditions to evaluate genotype effects on body temperature regulation. Genotypes evaluated were Holstein, Jersey, Jersey x Holstein and Swedish Red x Holstein. The comparison of Holstein and Jersey versus Jersey x Holstein provided a test of whether heterosis effects body temperature regulation. Cows were fitted with intravaginal temperature recording devices that measured vaginal temperature every 15 min for 7 days. Vaginal temperature was affected by time of day (P < 0.0001) and genotype x time (P < 0.0001) regardless of whether days in milk and milk yield were used as covariates. Additional analyses indicated that the Swedish Red x Holstein had a different pattern of vaginal temperatures than the other three genotypes (Swedish Red x Holstein vs others x time; P < 0.0001) and that Holstein and Jersey had a different pattern than Jersey x Holstein [(Holstein + Jersey vs Jersey x Holstein) x time, P < 0.0001]. However, Holstein had a similar pattern to Jersey [(Holstein vs Jersey) x time, P > 0.10]. These genotype x time interactions reflect two effects. First, Swedish Red x Holstein had higher vaginal temperatures than the other genotypes in the late morning and afternoon but not after the evening milking. Secondly, Jersey x Holstein had lower vaginal temperatures than other genotypes in the late morning and afternoon and again in the late night and early morning. Results point out that there are effects of specific genotypes and evidence for heterosis on regulation of body temperature of lactating cows maintained under grazing conditions and suggest that genetic improvement for thermotolerance through breed choice or genetic selection is possible.
---
paper_title: Impact of climate on thermal rhythm in pastoral sheep

paper_content:

Abstract The effects of environmental conditions on temperature rhythms were investigated in ewe lambs at pasture. Two groups of 20 lambs had heart rate (HR), vaginal temperature ( T v ), ear-canal temperature ( T c ) and ear-pinna temperature ( T p ) monitored continuously for 3 days. Climatic conditions were recorded at the same time and Temperature Humidity Index (THI) calculated. One group experienced fine clear weather for the 3 days, the other group experienced 2 days of heavy rain. During periods of fine weather, the daily rhythm for T v and T c was monophasic. However, heavy rain and a constant THI reduced the amplitude of the recorded temperature rhythms. Daily T v and T c patterns correlated strongly with THI, with a phase lag of 2 h. Peak T v and T c were at approximately 17:00 h each day. Mean maximum daily amplitudes were approximately 1.3 °C for T v and T c . Mean T v was 39.3±0.1 and 39.6±0.1 for weeks 1 and 2, respectively, while mean T c was 38.9±0.1 and 39.2±0.1. Changes in T v and T c were closely correlated. We conclude that climate has a major effect on body temperature rhythms.
---
paper_title: Predicting time of parturition from changing vaginal temperature measured by data-logging apparatus in beef cows with twin fetuses.

paper_content:

Vaginal temperatures (VT) of crossbred (Japanese Black crossed Holstein-Friesian) beef cows (n = 31) were measured by a data-logging apparatus to obtain serial data from days 0 to 6 before parturition. For both single and twin pregnancies, no significant differences were observed in VT during days 3-6 before parturition. Maternal VT was not affected by maternal weight just after parturition, parity, fetal sex, or total fetal litter weight. Average of twin litter weights for two males (MM) and two females (FF) had the strong positive correlations (r = 0.84; P < 0.05) with maternal VT, whereas twin weights of mixed-gender twins (FM) did not correlate with maternal VT (r = -0.26; P = 0.61). Maternal temperature decreased as weights of the female fetus of FM twins became heavier (r = -0.82; P < 0.05). In contrast, maternal VT of FF and MM twins increased as twin weights increased. We defined when the VT began to decrease before parturition by two different methods. One was the "same hours method" where differences in VT between a particular time of day and the corresponding time of the preceding day were compared when the VT was consistently > or =0.3 or > or =0.5 degrees C for more than 3h. The second method was the "maximum-minimum method" where decreased in the maximum or the minimum values of the day over > or =0.3 and > or =0.5 degrees C were compared to values of preceding day. Onset of decreased VT before expulsion was not different between singletons and twins. In an attempt to define the critical condition in predicting parturition, we estimated assumable predicting probability using the 31 cows that were collected VT. When the parturition occurred within 60 h in the "same hours method" and 72 h since VT was > or =0.3 degrees C and in the "maximum-minimum method", the assumable probability was 100%. In verification experiment under these condition, the "same hours method" had a higher probability of predicting the time of parturition than the "maximum-minimum method", and it was possible to detect the onset of decreased VT at the correct time by the minutes. We concluded that "same hours method" was useful for predicting parturition time in cattle with single and twin pregnancies by the serial measurement of vaginal temperature.
---
paper_title: Strategies to reduce feedlot cattle heat stress: Effects on tympanic temperature

paper_content:

Three experiments were conducted to evaluate the effect of different management strategies on body temperature of feedlot steers finished in the summer months. In Exp. 1, 24 crossbred steers were chosen to assess the effect of altered feed intake and feeding time on tympanic temperature (TT) response. Managed feeding (MF) treatments were applied for 22 d only and provided 1) ad libitum access to feed at 0800 (ADLIB), 2) feed at 1600 with amount adjusted so that no feed was available at 0800 (BKMGT), 3) feed at 1600 at 85% of predicted ad libitum levels (LIMFD). During heat stress conditions on d 20 to 22 of MF, LIMFD and BKMGT had lower (P < 0.05) TT than ADLIB from 2100 through 2400. A carryover effect of limit-feeding was evident during a severe heat episode (d 36 to 38) with LIMFD steers having lower (P < 0.05) TT than ADLIB. In Exp. 2, TT were obtained from 24 crossbred steers assigned to three treatments, consisting of no water application (CON), water applied to feedlot mound surfaces from 1000 to 1200 (AM) or 1400 to 1600 (PM). From 2200 to 0900 and 1200 to 1400, steers assigned to morning sprinkling treatment had lower (P < 0.05) TT than steers assigned to afternoon sprinkling treatment. In Exp. 3, 24 steers were utilized in a 2 x 2 factorial arrangement of treatments with factors of feeding time [0800 (AMF) and 1400 (PMF)] and sprinkling (WET and DRY). Tympanic temperatures were monitored under hot environmental conditions on d 30 to 32 and 61 to 62. A feeding time x sprinkling interaction (P < 0.001) was evident on d 30 to 32, although AMF/DRY steers had the highest (P < 0.05) TT. On d 61 to 62, TT of PMF steers was higher (P < 0.05) than AMF between 1500 to 1800. Use of sprinklers can effectively reduce TT of feedlot cattle, whereas shifting to an afternoon vs morning feeding time was most beneficial when bunks were empty several hours prior to feeding.
---
paper_title: Non-invasive measurement of stress in dairy cows using infrared thermography

paper_content:

Abstract The possibility that changes in eye temperature, measured using infrared thermography (IRT), can detect stress in dairy cattle was examined by six different stimulations of the stress axis. Six cows were given six treatments in a random Latin-square design: 1) Control (saline) 2) ACTH (0.05 mg Synacthen) 3) bCRH (20 μg) 4) bCRH (40 μg) 5) epinephrine (1.4 μg /kg liveweight) and 6) social isolation. Treatments were administered at time 0 and blood samples were taken at − 30, − 15, 0, 5, 10, 15, 20, 30, 40, 50, 60, 75, 90, 120, 180 and 240 min except for epinephrine which was sampled at − 30, − 15, − 10, − 5, 0, 2, 5, 10, 15, 20, 30, 45, 60, 90 and 120 min. Core body temperature was recorded every 10 min and eye images collected every 2 min. Eye temperature and cortisol increased following catheterization ( P P P P
---
paper_title: Measurement of horse core body temperature

paper_content:

Abstract Horse core body temperature (CBT) was monitored by three methods to compare three distinct physiological locations (blood temperature, BT; rectal temperature, RT; and telemetry-based gastrointestinal temperature, GT). Calibrated results indicate that CBT was different for each location (0.5 °C greater GT vs. RT; 1.0 °C greater GT vs. BT). The diurnal CBT average, minimum, and maximum were 38.0, 37.6, and 38.5 °C, respectively; and the telemetry-based system for measuring GT applied in this study is an acceptable alternative method for monitoring core body temperature in horses.
---
paper_title: Assessment of the use of temperature-sensitive microchips to determine core body temperature in goats

paper_content:

Body temperature was measured at five different body sites (retroperitoneum, groin, semimembranosus muscle, flank and shoulder) using temperature-sensitive microchips implanted in five female goats, and compared with the core body and rectal temperatures. Body temperature was measured while the goats were kept in different ambient temperatures, with and without radiant heat, as well as during a fever induced experimentally by injection of bacterial lipopolysaccharide. Bland-Altman limit of agreement analysis was used to compare the temperature measurements at the different body sites during the different interventions. Temperatures measured by the microchip implanted in the retroperitoneum showed the closest agreement (mean 0.2°C lower) with core and rectal temperatures during all interventions, whereas temperatures measured by the microchips implanted in the groin, muscle, flank and shoulder differed from core body temperature by up to 3.5°C during the various interventions.
---
paper_title: Sensors for dynamic physiological measurements

paper_content:

Stress research on agricultural production animals involves monitoring of bio-energetic responses to environmental challenges. Automated monitoring of physiological and behavioral responses of animals has the advantages of reducing labor, increasing the frequency of observation, and reducing bias and observer influence, but automation requires specialized instrumentation. Equipment has been developed or adapted to meet specific monitoring needs for a range of animals and facilities. This paper summarizes work related to cattle and swine stress research at the US Meat Animal Research Center, and specifically examines recording of body temperature, respiration rate, livestock safety monitoring and electronic identification. Much of this work has been reported previously and has been consolidated here to provide an overview of sensor development and application.
---
paper_title: Advances in Management of Poultry Production Using Biotelemetry

paper_content:

In this chapter, the authors review recent developments in the use of biotelemetry in poultry production. The chapter begins with an overview of advancements in biotelemetry and outlines the types of equipment that are commercially available as well as those adapted and developed by researchers primarily for use in farm animals. The authors then highlight the significant milestones achieved by the scientific community in using biotelemetry towards a more holistic poultry production guided by birds’ physiological responses to environmental stressors. In particular, the authors discuss efforts at the University of Georgia towards building the next generation closed-loop poultry environmental controller which responds directly and in real-time to physiological needs of the birds. Biotelemetry is defined as the remote detection and measurement of physiological, bioelectrical, and behavioral variables to monitor function, activity, or condition of conscious unrestrained humans or animals. This encompasses a broad range of techniques of varying invasiveness including video monitoring, non-contact thermometry, radio tracking and the use of internally or externally mounted remote sampling systems (Morton et al., 2003). Biotelemetry is not a new concept and it was first introduced by Einthoven in 1903 when he measured the electrocardiogram using immersion electrodes remotely connected to a galvanometer via telephone lines (Cromwell et al., 1973, as cited in Hamrita et al., 1998). In later years, NASA played a big role in the advancement of biotelemetry by using it to transmit astronaut biomedical data such as heart rate and body temperature to earth. In (N. F. Guler & Ubeyli, 2002), the authors provide a detailed history of early uses and developments of biotelemetry. Biotelemetry consists of sensing the variable of interest from the animal using miniature sensors or transducers. These can be placed on the animal, ingested by the animal, or implanted inside the animal by means of injection or surgery. The output of the sensor or transducer is modulated to a form which can be transmitted wirelessly over a distance from the animal to a receiver using an embedded transmitter. The received signal is demodulated and the measured variable extracted through proper signal conditioning and calibration by the data acquisition system. Biotelemetry data has been transmitted through every medium including air, vacuum, water, and biologic tissue using a variety of modulating carriers such as electromagnetic waves (especially at radiofrequencyhence the name radiotelemetry), light, and ultrasound (N. F. Guler & Ubeyli, 2002). By far the most common carriers of biotelemetry data are radio waves. Due to the proliferation of biotelemetry in recent years, the Federal
---
paper_title: Assessment of the use of temperature-sensitive microchips to determine core body temperature in goats

paper_content:

Body temperature was measured at five different body sites (retroperitoneum, groin, semimembranosus muscle, flank and shoulder) using temperature-sensitive microchips implanted in five female goats, and compared with the core body and rectal temperatures. Body temperature was measured while the goats were kept in different ambient temperatures, with and without radiant heat, as well as during a fever induced experimentally by injection of bacterial lipopolysaccharide. Bland-Altman limit of agreement analysis was used to compare the temperature measurements at the different body sites during the different interventions. Temperatures measured by the microchip implanted in the retroperitoneum showed the closest agreement (mean 0.2°C lower) with core and rectal temperatures during all interventions, whereas temperatures measured by the microchips implanted in the groin, muscle, flank and shoulder differed from core body temperature by up to 3.5°C during the various interventions.
---
paper_title: Comparison of methods of temperature measurement in swine

paper_content:

The purpose of these experiments was to test the equivalence of pulmonary artery, urinary bladder, tympanic, rectal and femoral artery methods of temperature measurement in healthy and critically ill swine under clinical intensive care unit (ICU) conditions using a prospective, time series design. First, sensors were tested for error and sensitivity to change in temperature with a precision-controlled water bath and a laboratory-certified digital thermometer for temperatures 34-42°C. There was virtually no systematic (bias) or random (precision) error (<0.2°C). The bladder sensor had the slowest response time to change in temperature (105-120 s). Next, testing was done in an experimental porcine ICU in a non-profit research institution with four male, sedated, and mechanically ventilated domestic farm pigs. The in vivo experiments were conducted over periods of 41-168 h with temperatures measured every 1-5 s. The bladder, tympanic and rectal methods had unacceptable bias (≥0.5°C) and/or precision (≥0.2°C)...
---
paper_title: Advances in Management of Poultry Production Using Biotelemetry

paper_content:

In this chapter, the authors review recent developments in the use of biotelemetry in poultry production. The chapter begins with an overview of advancements in biotelemetry and outlines the types of equipment that are commercially available as well as those adapted and developed by researchers primarily for use in farm animals. The authors then highlight the significant milestones achieved by the scientific community in using biotelemetry towards a more holistic poultry production guided by birds’ physiological responses to environmental stressors. In particular, the authors discuss efforts at the University of Georgia towards building the next generation closed-loop poultry environmental controller which responds directly and in real-time to physiological needs of the birds. Biotelemetry is defined as the remote detection and measurement of physiological, bioelectrical, and behavioral variables to monitor function, activity, or condition of conscious unrestrained humans or animals. This encompasses a broad range of techniques of varying invasiveness including video monitoring, non-contact thermometry, radio tracking and the use of internally or externally mounted remote sampling systems (Morton et al., 2003). Biotelemetry is not a new concept and it was first introduced by Einthoven in 1903 when he measured the electrocardiogram using immersion electrodes remotely connected to a galvanometer via telephone lines (Cromwell et al., 1973, as cited in Hamrita et al., 1998). In later years, NASA played a big role in the advancement of biotelemetry by using it to transmit astronaut biomedical data such as heart rate and body temperature to earth. In (N. F. Guler & Ubeyli, 2002), the authors provide a detailed history of early uses and developments of biotelemetry. Biotelemetry consists of sensing the variable of interest from the animal using miniature sensors or transducers. These can be placed on the animal, ingested by the animal, or implanted inside the animal by means of injection or surgery. The output of the sensor or transducer is modulated to a form which can be transmitted wirelessly over a distance from the animal to a receiver using an embedded transmitter. The received signal is demodulated and the measured variable extracted through proper signal conditioning and calibration by the data acquisition system. Biotelemetry data has been transmitted through every medium including air, vacuum, water, and biologic tissue using a variety of modulating carriers such as electromagnetic waves (especially at radiofrequencyhence the name radiotelemetry), light, and ultrasound (N. F. Guler & Ubeyli, 2002). By far the most common carriers of biotelemetry data are radio waves. Due to the proliferation of biotelemetry in recent years, the Federal
---
paper_title: Estimating metabolic heat loss in birds and mammals by combining infrared thermography with biophysical modelling.

paper_content:

Infrared thermography (IRT) is a technique that determines surface temperature based on physical laws of radiative transfer. Thermal imaging cameras have been used since the 1960s to determine the surface temperature patterns of a wide range of birds and mammals and how species regulate their surface temperature in response to different environmental conditions. As a large proportion of metabolic energy is transferred from the body to the environment as heat, biophysical models have been formulated to determine metabolic heat loss. These models are based on heat transfer equations for radiation, convection, conduction and evaporation and therefore surface temperature recorded by IRT can be used to calculate heat loss from different body regions. This approach has successfully demonstrated that in birds and mammals heat loss is regulated from poorly insulated regions of the body which are seen to be thermal windows for the dissipation of body heat. Rather than absolute measurement of metabolic heat loss, IRT and biophysical models have been most useful in estimating the relative heat loss from different body regions. Further calibration studies will improve the accuracy of models but the strength of this approach is that it is a non-invasive method of measuring the relative energy cost of an animal in response to different environments, behaviours and physiological states. It is likely that the increasing availability and portability of thermal imaging systems will lead to many new insights into the thermal physiology of endotherms.
---
paper_title: Insights into animal temperature adaptations revealed through thermal imaging

paper_content:

AbstractInfrared thermal technology allows for the real-time visualisation of fixed or transient changes in the long-wave radiative energy emanating from an object, in essence, allowing for the estimation of surface temperature. Animal surface temperatures are, therefore, readily detected using this technology, allowing for the assessment of physiological responses associated with the regulation of body temperature. In this paper, we will introduce some recent advances made possible or enhanced through the use of thermal imaging. In particular, this imaging technology has shed light on the regulation of peripheral blood flow in endothermic animals, on the dynamics of animal heat transfer in complex thermal environments, on the production of heat associated with metabolism and on the importance of evaporative heat loss to respiratory function and its potential contribution to preventing overheating of the brain. More than a simple imager for temperature, this technology has the potential to contribute a gr...
---
paper_title: Applications of thermal imaging in avian science

paper_content:

Thermal imaging, or infrared thermography, has been used in avian science since the 1960s. More than 30 species of birds, ranging in size from passerines to ratites, have been studied using this technology. The main strength of this technique is that it is a non-invasive and non-contact method of measuring surface temperature. Its limitations and measurement errors are well understood and suitable protocols have been developed for a variety of experimental settings. Thermal imaging has been used most successfully for research on the thermal physiology of captive species, including poultry. In comparison with work on mammals, thermal imaging has been less used for population counts, other than for some large bird species. However, more recently it has shown greater success for detection of flight paths and migration. The increasing availability and reduced cost of thermal imaging systems is likely to lead to further application of this technology in studies of avian welfare, disease monitoring, energetics, behaviour and population monitoring.
---
paper_title: Non-invasive continuous core temperature measurement by zero heat flux

paper_content:

Reliable continuous core temperature measurement is of major importance for monitoring patients. The zero heat flux method (ZHF) can potentially fulfil the requirements of non-invasiveness, reliability and short delay time that current measurement methods lack. The purpose of this study was to determine the performance of a new ZHF device on the forehead regarding these issues. Seven healthy subjects performed a protocol of 10 min rest, 30 min submaximal exercise (average temperature increase about 1.5 °C) and 10 min passive recovery in ambient conditions of 35 °C and 50% relative humidity. ZHF temperature (Tzhf) was compared to oesophageal (Tes) and rectal (Tre) temperature. ΔTzhf-Tes had an average bias standard deviation of 0.17 ± 0.19 °C in rest, -0.05 ± 0.18 °C during exercise and -0.01 ± 0.20 °C during recovery, the latter two being not significant. The 95% limits of agreement ranged from -0.40 to 0.40 °C and Tzhf had hardly any delay compared to Tes. Tre showed a substantial delay and deviation from Tes when core temperature changed rapidly. Results indicate that the studied ZHF sensor tracks Tes very well in hot and stable ambient conditions and may be a promising alternative for reliable non-invasive continuous core temperature measurement in hospital. © 2011 Institute of Physics and Engineering in Medicine.
---
paper_title: The non-invasive and automated detection of bovine respiratory disease onset in receiver calves using infrared thermography

paper_content:

Bovine respiratory disease complex (BRD) causes considerable economic loss and biosecurity cost to the beef industry globally and also results in significant degradation to the welfare of affected animals. The successful treatment of this disease depends on the early, timely and cost effective identification of affected animals. The objective of the present study was to investigate the use of an automated, RFID driven, noninvasive infrared thermography technology to determine BRD in cattle. Sixty-five calves averaging 220 kg were exposed to standard industry practices of transport and auction. The animals were monitored for BRD using conventional biometric signs for clinical scores, core temperatures, haematology, serum cortisol and infrared thermal values over 3 weeks. The data collected demonstrated that true positive animals for BRD based on a gold standard including core temperature, clinical score, white blood cell number and neutrophil/lymphocyte ratio displayed higher peak infrared thermal values of 35.7 ± 0.35 °C compared to true negative animals 34.9 ± 0.22 °C (P < 0.01). The study also demonstrated that such biometric data can be non-invasively and automatically collected based on a system developed around the animal’s water station. It is concluded that the deployment of such systems in the cattle industry would aid animal managers and practitioners in the identification and management of BRD in cattle populations.
---
paper_title: A New Telemetry System for Measuring Core Body Temperature in Livestock and Poultry

paper_content:

Core body temperature is an important physiological measure of animal thermoregulatory responses to environmental stimuli. A new telemetric body temperature measurement system was evaluated by three independent laboratories for its research application in poultry, swine, beef, and dairy cattle. In the case of poultry and swine, the system employs surgeryfree temperature sensors that are orally administered to allow short-term monitoring. Computational algorithms were developed and used to filter out spurious data. The results indicate that successful employment of the body-temperature measurement method - telemetric or other measurement systems such as rectal or tympanic method, will depend on the specific application. However, due to the cost of the system, the surgeries involved (in some applications), and the need for filtering of data, careful consideration needs to be given to ensure that telemetry is the ideal method for the experiment protocol.
---
paper_title: Advances in Management of Poultry Production Using Biotelemetry

paper_content:

In this chapter, the authors review recent developments in the use of biotelemetry in poultry production. The chapter begins with an overview of advancements in biotelemetry and outlines the types of equipment that are commercially available as well as those adapted and developed by researchers primarily for use in farm animals. The authors then highlight the significant milestones achieved by the scientific community in using biotelemetry towards a more holistic poultry production guided by birds’ physiological responses to environmental stressors. In particular, the authors discuss efforts at the University of Georgia towards building the next generation closed-loop poultry environmental controller which responds directly and in real-time to physiological needs of the birds. Biotelemetry is defined as the remote detection and measurement of physiological, bioelectrical, and behavioral variables to monitor function, activity, or condition of conscious unrestrained humans or animals. This encompasses a broad range of techniques of varying invasiveness including video monitoring, non-contact thermometry, radio tracking and the use of internally or externally mounted remote sampling systems (Morton et al., 2003). Biotelemetry is not a new concept and it was first introduced by Einthoven in 1903 when he measured the electrocardiogram using immersion electrodes remotely connected to a galvanometer via telephone lines (Cromwell et al., 1973, as cited in Hamrita et al., 1998). In later years, NASA played a big role in the advancement of biotelemetry by using it to transmit astronaut biomedical data such as heart rate and body temperature to earth. In (N. F. Guler & Ubeyli, 2002), the authors provide a detailed history of early uses and developments of biotelemetry. Biotelemetry consists of sensing the variable of interest from the animal using miniature sensors or transducers. These can be placed on the animal, ingested by the animal, or implanted inside the animal by means of injection or surgery. The output of the sensor or transducer is modulated to a form which can be transmitted wirelessly over a distance from the animal to a receiver using an embedded transmitter. The received signal is demodulated and the measured variable extracted through proper signal conditioning and calibration by the data acquisition system. Biotelemetry data has been transmitted through every medium including air, vacuum, water, and biologic tissue using a variety of modulating carriers such as electromagnetic waves (especially at radiofrequencyhence the name radiotelemetry), light, and ultrasound (N. F. Guler & Ubeyli, 2002). By far the most common carriers of biotelemetry data are radio waves. Due to the proliferation of biotelemetry in recent years, the Federal
---
paper_title: Estimating metabolic heat loss in birds and mammals by combining infrared thermography with biophysical modelling.

paper_content:

Infrared thermography (IRT) is a technique that determines surface temperature based on physical laws of radiative transfer. Thermal imaging cameras have been used since the 1960s to determine the surface temperature patterns of a wide range of birds and mammals and how species regulate their surface temperature in response to different environmental conditions. As a large proportion of metabolic energy is transferred from the body to the environment as heat, biophysical models have been formulated to determine metabolic heat loss. These models are based on heat transfer equations for radiation, convection, conduction and evaporation and therefore surface temperature recorded by IRT can be used to calculate heat loss from different body regions. This approach has successfully demonstrated that in birds and mammals heat loss is regulated from poorly insulated regions of the body which are seen to be thermal windows for the dissipation of body heat. Rather than absolute measurement of metabolic heat loss, IRT and biophysical models have been most useful in estimating the relative heat loss from different body regions. Further calibration studies will improve the accuracy of models but the strength of this approach is that it is a non-invasive method of measuring the relative energy cost of an animal in response to different environments, behaviours and physiological states. It is likely that the increasing availability and portability of thermal imaging systems will lead to many new insights into the thermal physiology of endotherms.
---
paper_title: Monitoring the body temperature of cows and calves using video recordings from an infrared thermography camera

paper_content:

The aim of this study was to assess the variability of temperatures measured by a video-based infrared camera (IRC) in comparison to rectal and vaginal temperatures. The body surface temperatures of cows and calves were measured contactless at different body regions using videos from the IRC. Altogether, 22 cows and 9 calves were examined. The differences of the measured IRC temperatures among the body regions, i.e. eye (mean: 37.0 °C), back of the ear (35.6 °C), shoulder (34.9 °C) and vulva (37.2 °C), were significant (P < 0.01), except between eye and vulva (P = 0.99). The quartile ranges of the measured IRC temperatures at the 4 above mentioned regions were between 1.2 and 1.8 K. Of the investigated body regions the eye and the back of the ear proved to be suitable as practical regions for temperature monitoring. The temperatures of these 2 regions could be gained by the use of the maximum temperatures of the head and body area. Therefore, only the maximum temperatures of both areas were used for further analysis. The data analysis showed an increase for the maximum temperature measured by IRC at head and body area with an increase of rectal temperature in cows and calves. The use of infrared thermography videos has the advantage to analyze more than 1 picture per animal in a short period of time, and shows potential as a monitoring system for body temperatures in cattle.
---
paper_title: A Review of Wireless Sensor Technologies and Applications in Agriculture and Food Industry: State of the Art and Current Trends

paper_content:

The aim of the present paper is to review the technical and scientific state of the art of wireless sensor technologies and standards for wireless communications in the Agri-Food sector. These technologies are very promising in several fields such as environmental monitoring, precision agriculture, cold chain control or traceability. The paper focuses on WSN (Wireless Sensor Networks) and RFID (Radio Frequency Identification), presenting the different systems available, recent developments and examples of applications, including ZigBee based WSN and passive, semi-passive and active RFID. Future trends of wireless communications in agriculture and food industry are also discussed.
---
paper_title: Validity and reliability of temperature measurement by heat flow thermistors, flexible thermocouple probes and thermistors in a stirred water bath.

paper_content:

We determined the validity and reliability of heat flow thermistors, flexible thermocouple probes and general purpose thermistors compared with a calibrated reference thermometer in a stirred water bath. Validity (bias) was defined as the difference between the observed and criterion values, and reliability as the repeatability (standard deviation or typical error) of measurement. Data were logged every 5 s for 10 min at water temperatures of 14, 26 and 38 °C for ten heat flow thermistors and 24 general purpose thermistors, and at 35, 38 and 41 °C for eight flexible thermocouple probes. Statistical analyses were conducted using spreadsheets for validity and reliability, where an acceptable bias was set at ±0.1 °C. None of the heat flow thermistors, 17% of the flexible thermocouple probes and 71% of the general purpose thermistors met the validity criterion for temperature. The inter-probe reliabilities were 0.03 °C for heat flow thermistors, 0.04 °C for flexible thermocouple probes and 0.09 °C for general purpose thermistors. The within trial intra-probe reliability of all three temperature probes was 0.01 °C. The results suggest that these temperature sensors should be calibrated individually before use at relevant temperatures and the raw data corrected using individual linear regression equations.
---
paper_title: Applications of thermal imaging in avian science

paper_content:

Thermal imaging, or infrared thermography, has been used in avian science since the 1960s. More than 30 species of birds, ranging in size from passerines to ratites, have been studied using this technology. The main strength of this technique is that it is a non-invasive and non-contact method of measuring surface temperature. Its limitations and measurement errors are well understood and suitable protocols have been developed for a variety of experimental settings. Thermal imaging has been used most successfully for research on the thermal physiology of captive species, including poultry. In comparison with work on mammals, thermal imaging has been less used for population counts, other than for some large bird species. However, more recently it has shown greater success for detection of flight paths and migration. The increasing availability and reduced cost of thermal imaging systems is likely to lead to further application of this technology in studies of avian welfare, disease monitoring, energetics, behaviour and population monitoring.
---
paper_title: Assessment of an injectable RFID temperature sensor for indication of horse well-being

paper_content:

This research investigated the performance and placement of an injectable radio frequency identification (RFID) and temperature sensor to monitor the body temperature of horses. Eleven sensors were calibrated to assess reliability (accuracy and repeatability) of the temperature readings. Results of four separate calibration trials demonstrated significant variability in both accuracy and repeatability. To quantify accuracy, the regression standard errors (SE) were placed into four performance categories: 4, 0, 2 and 3 excellent (SE = 0.5°C); 2, 1, 7, and 1 good (0.5°C < SE = 0.75°C); 2, 3, 0, and 7 marginal (0.75oC < SE = 1.0°C); and 3, 7, 2, 0 poor (SE < 1.0oC) sensors in each of the performance categories for the four calibration trials, respectively. Three of the eleven sensors evaluated were found to be repeatable, however, with marginal accuracy. Based on these results it is recommended that the temperature system be calibrated before use.
---
paper_title: Evaluation of a newly developed monitor of deep body temperature

paper_content:

In 1971, Fox and Solman [1] first described the use of an electronic servocontrolled system to achieve almost complete thermal insulation. The temperature measuring probe has two thermistors separated by a thermal insulator, with an electrical heating element mounted at the rear of the probe. The temperatures on the two sides of the insulating layer, as detected by the thermistors, are compared by a differential amplifier. The error signal is used to control the heater current in such a way as to achieve a situation in which no temperature gradient arises across the insulating layer and thus no heat flows out through this layer. This technique is called the “zero-heat-flow” method. As long as a zero-heat-flow condition is maintained, the probe is equivalent to an ideal thermal insulator; i.e., heat loss from the skin surface beneath the probe is prevented and, after a sufficient time, the skin surface temperature will equilibrate with the deep tissue temperature. Monitoring of deep body temperature, especially from the forehead, is now often used in cardiac surgery in Japan. Deep temperature monitoring has also been used in intensive care units [2] and for monitoring of circulatory failure [3]. Although the monitoring of deep body temperature is noninvasive, clinical application of the monitor is limited by the slow initial response time and the slow response time for rapid internal temperature changes. The initial response time of a deep temperature thermometer, extending from the time when the probe is placed on the body surface to the time when the measured temperature become stable, seems to be long. The
---
paper_title: Effect of temperature level on thermal acclimation in Large White growing pigs.

paper_content:

The effect of temperature level (24°C, 28°C, 32°C or 36°C) on performance and thermoregulatory response in growing pigs during acclimation to high ambient temperature was studied on a total of 96 Large White barrows. Pigs were exposed to 24°C for 10 days (days −10 to −1, P0) and thereafter to a constant temperature of 24°C, 28°C, 32°C or 36°C for 20 days. Pigs were housed in individual metal slatted pens, allowing a separate collection of faeces and urine and given ad libitum access to feed. Rectal (RT) and cutaneous (CT) temperatures and respiration rate (RR) were measured three times daily (0700, 1200 and 1800 h) every 2 to 3 days during the experiment. From day 1 to 20, the effect of temperature on average daily feed intake (ADFI) and BW gain (average daily gain, ADG) was curvilinear. The decrease of ADFI averaged 90 g/day per °C between 24°C and 32°C and 128 g/day per °C between 32°C and 36°C. The corresponding values for ADG were 50 and 72 g/day per °C, respectively. The 20 days exposure to the experimental temperature was divided in two sub-periods (P1 and P2, from day 1 to 10 and from day 11 to 20, respectively). ADFI was not affected by duration of high-temperature exposure (i.e. P2 v . P1). The ADG was not influenced by the duration of exposure at 24°C and 28°C groups. However, ADG was higher at P2 than at P1 and this effect was temperature dependent (+130 and +458 g/day at 32°C and 36°C, respectively). In P2 at 36°C, dry matter digestibility significantly increased (+2.1%, P P
---
paper_title: Comparison of reticular and rectal core body temperatures in lactating dairy cows.

paper_content:

The Phase IV Cattle Temperature Monitoring System (CTMS; Phase IV Engineering Inc., Boulder, CO) marketed by MaGiiX (MaGiiX Inc., Post Falls, ID) uses a passive bolus equipped with a temperature sensor, a panel reader placed at a parlor entrance or exit to query the bolus, and a software package to collect, analyze, and view data. The biologically inert bolus resides in the cow's reticulum and is queried each time the cow passes the reader. Reticular temperature (RETT) and rectal temperature (RECT) were recorded simultaneously in the milking parlor exit lane in 4 consecutive milkings in each of 4 seasons, totaling 16 measurements per cow. The RETT were obtained by using the phase IV CTMS, whereas the RECT were obtained manually with a GLA M750 thermometer (GLA Agricultural Electronics, San Luis Obispo, CA). Data were edited to remove RETT likely to have been affected by a recent drinking bout. For the 2,042 observations used in analyses, means (+/-SD) were 39.28 (+/-0.41), 38.83 (+/-0.36), and 0.45 (+/-0.33) for RETT, RECT, and the difference between RETT and RECT, respectively. The RETT and RECT were strongly correlated (r = 0.645). The relationship between RETT and RECT varied by season, milking, housing system, and parity. Because dairy producers and veterinarians are accustomed to viewing rectal temperatures, equations to adjust reticular temperatures to a rectal-based scale may increase the utility of the phase IV CTMS. The resulting conversion equations were RECT = 19.23 + 0.496(RETT) for the a.m. milking and RECT = 15.88 + 0.587(RETT) for the p.m. milking.
---
paper_title: Implications of changes in core body temperature.

paper_content:

Dairy farmers and veterinarians have used body temperatures, most commonly rectal temperatures, to detect and manage febrile disease and changes in the state of cows (estrus and onset of calving) for many years. Mastitis, pneumonia, metritis, lameness, estrus, onset of parturition, heat stress, and subacute ruminal acidosis (SARA) are among the physiological conditions potentially correlated with body temperature that deviates from normal. Many new technologies have been introduced to measure body temperature of cattle at various locations, including rectum, ear (tympanic), vagina, reticulum-rumen, skin, and milk. While each location has its own advantages and disadvantages, temperature measurements at some of these locations can be automated for routine, frequent, and non-disruptive temperature recording. Systems for measurement of reticular temperature are available commercially. However, many factors other than the physiological conditions of interest affect reticular temperature. Among these are ambient temperature, food and water consumption, stage of lactation cycle, age, recumbency, activity level, stage of gestation, and of course, general health. The relationship between reticular and rectal temperatures appears to be relatively consistent, though the correlation is affected by time of season, housing system, and time of day. Reticular temperatures are affected by water intake, and substantially so for large volumes and extremely cold water; and dips in reticular temperature following water consumption must be considered when interpreting observations. Research is continuing to assess the ability of reticular temperature monitoring, perhaps in conjunction with other precision dairy farming tools, to allow earlier intervention with appropriate management. Success of early intervention will be the key to the ultimate success of any temperature monitoring technology.
---
paper_title: Technical note: The use of a telemetric system to continuously monitor ruminal temperature and to predict ruminal pH in cattle

paper_content:

Abstract The objective of this study was to compare a telemetric monitoring system to an existing in situ methodology (conventional system) of monitoring ruminal temperature and to validate its use to detect changes in ruminal pH (RpH). Four nonlactating, ruminally cannulated Holstein dairy cows (760±30kg of body weight, mean±standard deviation) housed in a tie-stall facility were used in the study. The experiment was conducted during the month of May and the recorded ambient temperature was 8.0±2.0°C (mean±SD). The cows were fed a diet consisting of chopped mixed hay (MH; 11.3% crude protein, 59.7% neutral detergent fiber, 17.3% nonfiber carbohydrate, 3.1% ether extract, and 11.3% ash; dry matter basis) during wk 1 and were gradually switched to a high-grain (HG) diet (11.6% crude protein, 30.2% neutral detergent fiber, 50.7% nonfiber carbohydrate, 3.0% ether extract, and 6.0% ash; dry matter basis) during wk 2. A conventional system that utilized an indwelling electrode was used to monitor RpH and ruminal temperature (RT C ) during d 6 and 7 of each week. The indwelling electrode was attached to a telemetric bolus and ruminal temperature (RT T ) was logged into a personal computer. The daily mean, minimum, and maximum RpH and duration (min/d) RpH C increased from 37.5C±0.1 in wk 1 to 38.6°C±0.1 in wk 2; there was also an increase from wk 1 to wk 2 in minimum and maximum daily RT C and durations (min/d) of RT C >38.0, >38.2, >38.4, and >38.6°C. These increases were not detectable with the telemetric system. Ruminal temperature obtained by the conventional system was 0.68°C±0.005 lower than RT T during MH feeding (wk 1), whereas RT C was 0.04°C±0.004 higher than RT T during HG feeding (wk 2). Daily minimum RpH was associated with maximum daily RT C and RT T during MH and HG feeding (R 2 =0.88 and 0.43, respectively). There was a high association between low RpH and high ruminal temperature, with the highest associations being between duration (min/d) of RpH C >39.0°C (R 2 =0.68) and RT T >39.2°C (R 2 =0.72). Unlike the telemetric system, the conventional system requires cow cannulation; therefore, the current study provided a noninvasive alternative for measuring ruminal temperature and the prediction of RpH. Additional studies are needed to develop an algorithm that accounts for diet type, seasonal variation in temperature, and core body temperature to predict subacute ruminal acidosis effectively on farm.
---
paper_title: Comparison of methods of temperature measurement in swine

paper_content:

The purpose of these experiments was to test the equivalence of pulmonary artery, urinary bladder, tympanic, rectal and femoral artery methods of temperature measurement in healthy and critically ill swine under clinical intensive care unit (ICU) conditions using a prospective, time series design. First, sensors were tested for error and sensitivity to change in temperature with a precision-controlled water bath and a laboratory-certified digital thermometer for temperatures 34-42°C. There was virtually no systematic (bias) or random (precision) error (<0.2°C). The bladder sensor had the slowest response time to change in temperature (105-120 s). Next, testing was done in an experimental porcine ICU in a non-profit research institution with four male, sedated, and mechanically ventilated domestic farm pigs. The in vivo experiments were conducted over periods of 41-168 h with temperatures measured every 1-5 s. The bladder, tympanic and rectal methods had unacceptable bias (≥0.5°C) and/or precision (≥0.2°C)...
---
paper_title: Scaling the daily oscillations of breathing frequency and skin temperature in mammals.

paper_content:

Among mammals, the peak-trough difference (PTD) of the circadian pattern of body temperature (T(b)) drops very little with the increase in body mass (W), despite the large increase in heat capacitance and thermal inertia. We asked whether this might be contributed by systematic differences in the circadian pattern of breathing frequency (f) and skin temperature (Tskin), which are parts of the control mechanisms of heat loss. Measurements had been conducted on animals of eight species, chosen to cover a four-fold range in W, while resting and awake. The oscillation of f preceded that of T(b) in 7 of the 8 species, and its acrophase did not correlate with W. The daily mean and PTD of f scaled with W in a similar manner (respectively, W(-)(23) and W(-)(0.29)), the PTD averaging about 20% of the daily mean. The circadian oscillations of Tskin, measured in specimens of five species at three locations (abdomen, ear and thigh), were in phase with T(b). Neither the PTD nor the acrophase of Tskin changed systematically with W. The differences between T(b) and Tskin (means, peaks and troughs) decreased significantly with W; on average, the T(b)-Tskin difference scaled to W(-)(0.19). In conclusion, the relative amplitudes and the acrophase of Tskin and f did not show systematic inter-species differences. The progressive increase of Tskin with W could be a factor in maintaining the PTD of T(b) within a narrow range among mammals of very different size.
---
paper_title: Genotype effects on body temperature in dairy cows under grazing conditions in a hot climate including evidence for heterosis.

paper_content:

We compared diurnal patterns of vaginal temperature in lactating cows under grazing conditions to evaluate genotype effects on body temperature regulation. Genotypes evaluated were Holstein, Jersey, Jersey x Holstein and Swedish Red x Holstein. The comparison of Holstein and Jersey versus Jersey x Holstein provided a test of whether heterosis effects body temperature regulation. Cows were fitted with intravaginal temperature recording devices that measured vaginal temperature every 15 min for 7 days. Vaginal temperature was affected by time of day (P < 0.0001) and genotype x time (P < 0.0001) regardless of whether days in milk and milk yield were used as covariates. Additional analyses indicated that the Swedish Red x Holstein had a different pattern of vaginal temperatures than the other three genotypes (Swedish Red x Holstein vs others x time; P < 0.0001) and that Holstein and Jersey had a different pattern than Jersey x Holstein [(Holstein + Jersey vs Jersey x Holstein) x time, P < 0.0001]. However, Holstein had a similar pattern to Jersey [(Holstein vs Jersey) x time, P > 0.10]. These genotype x time interactions reflect two effects. First, Swedish Red x Holstein had higher vaginal temperatures than the other genotypes in the late morning and afternoon but not after the evening milking. Secondly, Jersey x Holstein had lower vaginal temperatures than other genotypes in the late morning and afternoon and again in the late night and early morning. Results point out that there are effects of specific genotypes and evidence for heterosis on regulation of body temperature of lactating cows maintained under grazing conditions and suggest that genetic improvement for thermotolerance through breed choice or genetic selection is possible.
---
paper_title: Impact of climate on thermal rhythm in pastoral sheep

paper_content:

Abstract The effects of environmental conditions on temperature rhythms were investigated in ewe lambs at pasture. Two groups of 20 lambs had heart rate (HR), vaginal temperature ( T v ), ear-canal temperature ( T c ) and ear-pinna temperature ( T p ) monitored continuously for 3 days. Climatic conditions were recorded at the same time and Temperature Humidity Index (THI) calculated. One group experienced fine clear weather for the 3 days, the other group experienced 2 days of heavy rain. During periods of fine weather, the daily rhythm for T v and T c was monophasic. However, heavy rain and a constant THI reduced the amplitude of the recorded temperature rhythms. Daily T v and T c patterns correlated strongly with THI, with a phase lag of 2 h. Peak T v and T c were at approximately 17:00 h each day. Mean maximum daily amplitudes were approximately 1.3 °C for T v and T c . Mean T v was 39.3±0.1 and 39.6±0.1 for weeks 1 and 2, respectively, while mean T c was 38.9±0.1 and 39.2±0.1. Changes in T v and T c were closely correlated. We conclude that climate has a major effect on body temperature rhythms.
---
paper_title: Relationship between vaginal and tympanic membrane temperature in beef heifers

paper_content:

Vaginal and tympanic membrane temperatures were simultaneously monitored in nine beef heifers. Data not associated with ear infections were characterized by respective vaginal and tympanic membrane temperatures of 38.81 and 38.58 °C. A close relationship between the two temperatures was indicated by a correlation of 0.77 and residual standard deviation of 0.29 °C. Key words: Cattle, radiotelemetry, thermoregulation, tympanic membrane, vagina
---
paper_title: Development of a self-contained, indwelling vaginal temperature probe for use in cattle research

paper_content:

A device was developed to monitor the vaginal temperature of cattle in a research setting. This device decreases labor involved with monitoring body temperature compared with manual temperature readings, allows for continuous monitoring of vaginal temperature at 1 min intervals, and also allows for temperature measurements without the presence of a human handler or without restraint, which can agitate cattle. The device consists of a blank controlled internal drug release (CIDR) device (designed by Pfizer Animal Health as an indwelling vaginal probe) that holds an indwelling vaginal temperature probe logger. The fabrication of the vaginal probe costs approximately US $325 per unit. Similar rectal and vaginal temperature responses to lipopolysaccharide challenge were observed when vaginal and rectal temperatures were measured simultaneously in the same heifer (P40.05). Additionally, rectal and vaginal temperatures were highly correlated (r¼ 0.97; Po 0.0001). Similar to the rectal temperature monitoring device, the vaginal device allows for the measurement of vaginal temperature without the potential biases associated with the stress response produced as a reaction to the handling by and (or) presence of humans. The vaginal temperature recording device will provide researchers with an additional inexpensive tool to study physiological responses in female cattle. & 2011 Published by Elsevier Ltd.
---
paper_title: Strategies to reduce feedlot cattle heat stress: Effects on tympanic temperature

paper_content:

Three experiments were conducted to evaluate the effect of different management strategies on body temperature of feedlot steers finished in the summer months. In Exp. 1, 24 crossbred steers were chosen to assess the effect of altered feed intake and feeding time on tympanic temperature (TT) response. Managed feeding (MF) treatments were applied for 22 d only and provided 1) ad libitum access to feed at 0800 (ADLIB), 2) feed at 1600 with amount adjusted so that no feed was available at 0800 (BKMGT), 3) feed at 1600 at 85% of predicted ad libitum levels (LIMFD). During heat stress conditions on d 20 to 22 of MF, LIMFD and BKMGT had lower (P < 0.05) TT than ADLIB from 2100 through 2400. A carryover effect of limit-feeding was evident during a severe heat episode (d 36 to 38) with LIMFD steers having lower (P < 0.05) TT than ADLIB. In Exp. 2, TT were obtained from 24 crossbred steers assigned to three treatments, consisting of no water application (CON), water applied to feedlot mound surfaces from 1000 to 1200 (AM) or 1400 to 1600 (PM). From 2200 to 0900 and 1200 to 1400, steers assigned to morning sprinkling treatment had lower (P < 0.05) TT than steers assigned to afternoon sprinkling treatment. In Exp. 3, 24 steers were utilized in a 2 x 2 factorial arrangement of treatments with factors of feeding time [0800 (AMF) and 1400 (PMF)] and sprinkling (WET and DRY). Tympanic temperatures were monitored under hot environmental conditions on d 30 to 32 and 61 to 62. A feeding time x sprinkling interaction (P < 0.001) was evident on d 30 to 32, although AMF/DRY steers had the highest (P < 0.05) TT. On d 61 to 62, TT of PMF steers was higher (P < 0.05) than AMF between 1500 to 1800. Use of sprinklers can effectively reduce TT of feedlot cattle, whereas shifting to an afternoon vs morning feeding time was most beneficial when bunks were empty several hours prior to feeding.
---
paper_title: Measurement of horse core body temperature

paper_content:

Abstract Horse core body temperature (CBT) was monitored by three methods to compare three distinct physiological locations (blood temperature, BT; rectal temperature, RT; and telemetry-based gastrointestinal temperature, GT). Calibrated results indicate that CBT was different for each location (0.5 °C greater GT vs. RT; 1.0 °C greater GT vs. BT). The diurnal CBT average, minimum, and maximum were 38.0, 37.6, and 38.5 °C, respectively; and the telemetry-based system for measuring GT applied in this study is an acceptable alternative method for monitoring core body temperature in horses.
---
paper_title: Influence of endophyte consumption and heat stress on intravaginal temperatures, plasma lipid oxidation, blood selenium, and glutathione redox of mononuclear cells in heifers grazing tall fescue

paper_content:

A grazing experiment was conducted to assess the effects of wild-type endophyte-infected (E+) tall fescue consumption and elevated ambient temperatures on intravaginal temperatures, plasma lipid peroxidation, and glutathione redox of peripheral blood mononuclear cells. Angus heifers (n = 34) were allotted by BW to 4 blocks consisting of E+ and endophyte-free (E-) fescue pastures. Monthly, in June, July, and August, temperature loggers were fixed into blank controlled internal drug releasers and inserted into a subsample of heifers (n = 16) for 2 d. After 48 h, heifers were weighed, and blood (30 mL) was collected via jugular venipuncture. Peripheral blood mononuclear cells were isolated for analysis of glutathione peroxidase activity, glutathione reductase activity, and reduced:oxidized glutathione. Plasma malondialdehyde was evaluated as a marker of lipid peroxidation, and whole blood Se concentration was determined. Serum prolactin was assayed after the grazing period. Heifer ADG was greatest in August and least in July (P < 0.001). In August, heifers grazing E+ fescue exhibited greater (P < 0.05) afternoon intravaginal temperatures and temperature fluctuations than heifers grazing E- fescue. In July and August, all heifers had greater afternoon temperatures (P < 0.02) and less reduced:oxidized glutathione (P < 0.0001) than in June. Glutathione reductase activity of all heifers was greater in June (P = 0.03) than in July. Similarly, all heifers exhibited decreased glutathione peroxidase activity (P < 0.0008) in July, whereas whole blood Se was reduced (P < 0.0001) in July and August. No treatment or date effects were detected for malondialdehyde, but serum prolactin was reduced at the end of the grazing period (P = 0.008) in heifers stocked on E+ fescue. Using these markers, differences in oxidative stress were not detected between heifers consuming E+ fescue and those consuming E- fescue. Date effects indicating altered glutathione redox and enzyme activity may have been related to heat stress and nutritional limitations.
---
paper_title: Assessment of the use of temperature-sensitive microchips to determine core body temperature in goats

paper_content:

Body temperature was measured at five different body sites (retroperitoneum, groin, semimembranosus muscle, flank and shoulder) using temperature-sensitive microchips implanted in five female goats, and compared with the core body and rectal temperatures. Body temperature was measured while the goats were kept in different ambient temperatures, with and without radiant heat, as well as during a fever induced experimentally by injection of bacterial lipopolysaccharide. Bland-Altman limit of agreement analysis was used to compare the temperature measurements at the different body sites during the different interventions. Temperatures measured by the microchip implanted in the retroperitoneum showed the closest agreement (mean 0.2°C lower) with core and rectal temperatures during all interventions, whereas temperatures measured by the microchips implanted in the groin, muscle, flank and shoulder differed from core body temperature by up to 3.5°C during the various interventions.
---
paper_title: Correlation of rectal temperature and peripheral temperature from implantable radio-frequency microchips in Holstein steers challenged with lipopolysaccharide under thermoneutral and high ambient temperatures

paper_content:

Early detection of disease can speed treatment, slow spread of disease in a herd, and improve health status of animals. Immune stimulation increases rectal temperature (RT). Injectable radio-frequency implants (RFI) can provide temperature at the site of implantation. The fidelity of peripheral site temperature, determined by RFI, relative to RT is unknown in cattle. We hypothesized that during lipopolysaccharide (LPS) challenge, temperature at 3 peripheral sites would be similar to RT in steers (n = 4; BW 77 ± 2.1 kg). The 3 sites were 1) subcutaneous (SC) at the base of the ear (ET); 2) SC posterior to the poll (PT); and 3) SC beneath the umbilical fold (UT). Steers were housed in controlled temperature (CT) rooms (between 18 and 21°C; n = 2/room). Rectal temperature, ET, PT, and UT were recorded every 8 h daily. On d 7, 21, 22, 36, and 37, RT and RFI were taken every 5 min for 6 h, every 15 min for 3 h, and every 30 min for 15 h. To test RFI during a simulated immune challenge, LPS (E. coli 055:B5) was injected intravenously (i.v.) at 1000 h on d 22 and 37. Basal temperatures (°C) were RT (38.7 ± 0.20), ET (37.1 ± 0.86), PT (36.7 ± 0.57), and UT (36.3 ± 0.97). Rectal temperature increased to 39.9 ± 0.30°C after LPS, but ET, PT, and UT decreased. Heat stress also increases RT, which makes it difficult to identify sick animals using RT. The second hypothesis tested was that ET positively correlates to RT and negatively correlates to RT during LPS under heat stress. Four steers (127 ± 7.3 kg) were housed in CT chambers (n = 2/chamber), implanted with a RFI, and allowed 2 wk to acclimate. One chamber remained at 20°C, the other was increased to 34°C starting at 0800 h for a period of 48 h. The LPS was administered i.v. to all steers at 1000 h on d 2. After a 2-wk recovery at 20°C, the temperature was increased in the other chamber, resulting in a crossover design with each steer serving as its own control. Pearson's correlation coefficients for ET and RT were 0.30 (P < 0.01) during heat stress, 0.20 (P < 0.05) during heat stress with LPS challenge, 0.34 (P < 0.01) during thermoneutrality, and -0.42 (P < 0.01) during thermoneutrality with LPS. These data refute the hypothesis that RT and peripheral temperature move in synchrony after LPS challenge. These data suggest that individual response be considered when identifying models for use of ET, but these RFI have potential for use in the early detection of diseases that alter basal temperature.
---
paper_title: A study on the applicability of implantable microchip transponders for body temperature measurements in pigs

paper_content:

Background: The applicability of an electronic monitoring system using microchip transponders for measurement of body temperatures was tested in 6-week-old conventional Danish weaners infected with classical swine fever virus (CSFV). Subcutaneous tissue temperatures obtained by the implantable transponders were compared with rectal temperatures, recorded by a conventional digital thermometer. Methods: In a preliminary study, transponders were inserted subcutaneously at 6 different positions of the body of 5 pigs. The transponders positioned by the ear base provided the best correlation to rectal temperature. To test the stability of the monitoring system in a larger group of pigs, transponders were therefore inserted by the left ear base in a subsequent infection experiment with 30 pigs. Results: Generally, the microchip transponders measured a subcutaneous tissue temperature, which was about 1°C lower than the rectal temperature. However, a simple linear relationship between the measures of the two methods was found. Conclusions: Our study showed that the tested body monitoring system may represent a promising tool to obtain an approximate correlate of body temperatures in groups of pigs. In contrast, however, the tested system did not constitute a suitable tool to measure body temperatures of individual animals in the present pig infection experiment.
---
paper_title: Effects on fetal and maternal body temperatures of exposure of pregnant ewes to heat, cold, and exercise

paper_content:

We exposed Dorper-cross ewes at ∼120–135 days of gestation to a hot (40°C, 60% relative humidity) and a cold (4°C, 90% relative humidity) environment and to treadmill exercise (2.1 km/h, 5° gradien...
---
paper_title: Feto-Maternal Relationships in Goats During Heat and Cold Exposure

paper_content:

Maternal and fetal body temperatures were measured in five Boer goats, of mean mass 64 +/- 8 kg, using temperature-sensitive radiotelemeters implanted intra-abdominally. Body temperatures were recorded every 5 min. Throughout the last month of gestation, fetal temperature was approximately 0.6 (o)C higher than that of the mother, in normal laboratory conditions (ambient air temperature: 21-24 (o)C). This feto-maternal temperature difference between the goat fetus and its mother is similar to that found in other mammals, including sheep. When the pregnant goats were subjected to short-term heating and cooling, the difference between maternal and fetal body temperatures changed. Thus the mean difference between fetal and maternal body temperatures decreased from 0.4 to 0.2 (o)C during 2 h of heating, while it widened from 0.3 to 0.7 (o)C during 6 h of cooling. These data support the idea that the fetus is thermally protected from excursions of body temperature during changes in the mother's thermal environment. Reports of goat stock losses and abortions during cold spells in their natural habitats may be the result of more severe and/or prolonged cold exposures that not only adversely affect fetal or maternal body temperature, but also influence other aspects of metabolism. Experimental Physiology (2001) 86.2, 199-204.
---
paper_title: An implantable radio-telemetry system for remote monitoring of heart rate and deep body temperature in poultry

paper_content:

Abstract A radiotelemetry system for the remote monitoring and recording of ECG, heart rate and deep body temperature in poultry is described. The design of the package affords simple surgical implantation of the transmitter and sensors without interference with the animal's normal physiological function or behaviour. Evaluation of the system under laboratory conditions demonstrated accurate and reliable transmission and recording of the physiological signals, at ranges up to 10 m, during control periods and exposure to thermal stress. It is proposed that the system will prove particularly valuable in the continuous monitoring of physiological responses of unrestrained animals to both acute and chronic exposure to environmental stressors. Whilst intended for specific use in poultry, the system may find applications in many other species.
---
paper_title: Assessment of an injectable RFID temperature sensor for indication of horse well-being

paper_content:

This research investigated the performance and placement of an injectable radio frequency identification (RFID) and temperature sensor to monitor the body temperature of horses. Eleven sensors were calibrated to assess reliability (accuracy and repeatability) of the temperature readings. Results of four separate calibration trials demonstrated significant variability in both accuracy and repeatability. To quantify accuracy, the regression standard errors (SE) were placed into four performance categories: 4, 0, 2 and 3 excellent (SE = 0.5°C); 2, 1, 7, and 1 good (0.5°C < SE = 0.75°C); 2, 3, 0, and 7 marginal (0.75oC < SE = 1.0°C); and 3, 7, 2, 0 poor (SE < 1.0oC) sensors in each of the performance categories for the four calibration trials, respectively. Three of the eleven sensors evaluated were found to be repeatable, however, with marginal accuracy. Based on these results it is recommended that the temperature system be calibrated before use.
---
paper_title: The use of digital infrared thermal imaging to detect estrus in gilts

paper_content:

Abstract Yorkshire/Landrace crossbred gilts (N = 32) were evaluated using digital infrared thermal imaging (DITI) to discriminate between estrus and diestrus phases of the porcine estrous cycle. Gilts (N = 32) were part of an ongoing reproductive efficiency study involving the use of raw soybean (RSB; N = 15) versus soybean meal (SBM; N = 17) as a source of dietary protein. Gilts were monitored daily for signs of estrus using a teaser boar. Thermal images of vulva surface temperatures (TEMP) were recorded at standing estrus and diestrus. Measurements for analysis included minimum (MIN), maximum (MAX), mean (AVG), and standard deviation (SD) of temperature gradients. At imaging, ambient (AMB) and rectal temperatures (RT) were recorded, and blood samples taken for serum progesterone (P 4 ) concentration analysis (by RIA) to confirm stage of cycle. Mean serum progesterone values at estrus and diestrus were (mean ± SD) 1.0 ± 0.1 and 10.9 ± 0.8 ng/mL, respectively. Vulva MIN, MAX, and AVG thermal images were positively correlated with one another (P 0.05) between stages of the cycle. No differences (P > 0.05) in RT were detected between stages and RT was not significantly correlated with vulva thermal images. Diet had no significant effect on RT or vulva temperature.
---
paper_title: Detection of hoof lesions using digital infrared thermography in dairy cows.

paper_content:

Abstract The objective was to investigate infrared thermography (IRT) as a noninvasive diagnostic tool for early detection of foot pathologies in dairy cows. This was achieved by measuring changes in coronary band temperature before and after claw trimming in response to visual detection of abnormalities of the hooves. We hypothesized that by focusing on the coronary band region, IRT is able to detect lesions of the hind limbs of dairy cows associated with lameness. In this study, 626 individual observations were collected from 24 cows before and after claw trimming. Infrared thermography was used to assess the surface temperature of the coronary band (CB) region and skin (S), and the temperature difference (ΔT) between CB and S of the hind limbs. The average, minimum, and maximum surface temperatures were recorded in both regions. Temperatures of CB and S and ΔT were significantly higher in cows ≤200 d in milk than in cows >200 d in milk for all healthy hooves: 31.8±2.7 versus 29.8±3.6; 28.5±2.5 versus 27.2±3.3°C, and 3.31±1.7 versus 2.51±1.3°C, respectively. Temperatures of CB and S regions were positively correlated with ambient temperature. This association was best described by a linear model (R 2 =0.92 and 0.99, respectively). The temperatures of CB and S regions were 30.3±3.2°C and 27.3±2.9°C; 32.1±1.7°C and 28.6±2.1°C; and 33.8±1.3°C and 29.9±1.8°C for parlor temperatures of 12.2, 15.7, and 20.3°C, respectively. In the pre- and post-trimming data analysis, a significant difference was found in temperature of the coronary band between cows with lesions and cows without lesions. A threshold value was established to determine the temperature difference between lesion and nonlesion hind claws on CB at 0.64 and 1.09°C before and after claw trimming (sensitivity=85.7%, specificity=55.9%; and sensitivity=80.0%, specificity=82.9%, respectively) with the aim of detecting hoof lesions. In conclusion, the results demonstrate an increase in surface temperature of the lame limb when a hoof has a lesion.
---
paper_title: Early detection and prediction of infection using infrared thermography

paper_content:

Early detection and/or prediction of disease in an animal is the first step towards its successful treatment. The objective of this study was to investigate the capability of infrared thermography as a non-invasive, early detection method for identifying animals with a systemic infection. A viral infection model was adopted using 15 seronegative calves whose body weight averaged 172 kg. Ten of these calves were inoculated with Type 2 bovine viral diarrhoea virus (strain 24515) and five were separately housed and served as uninfected controls. A simultaneous comparison of infrared characteristics in both infected and control animals was conducted over approximately 15 d. In addition, measures of blood and saliva cortisol, immunoglobulin A, blood haptoglobin and clinical scores were obtained. Infrared temperatures, especially for facial scans, increased by 1.5°C to over 4°C (P < 0.01) several days to 1 wk before clinical scores or serum concentrations of acute phase protein indicated illness in the infected...
---
paper_title: Heart rate variability explored in the frequency domain: A tool to investigate the link between heart and behavior

paper_content:

Abstract The neural regulation of circulatory function is mainly effected through the interplay of the sympathetic and vagal outflows. This interaction can be explored by assessing cardiovascular rhythmicity with appropriate spectral methodologies. Spectral analysis of cardiovascular signal variability, and in particular of RR period (heart rate variability, HRV), is a widely used procedure to investigate autonomic cardiovascular control and/or target function impairment. The oscillatory pattern which characterizes the spectral profile of heart rate and arterial pressure short-term variability consists of two major components, at low (LF, 0.04–0.15 Hz) and high (HF, synchronous with respiratory rate) frequency, respectively, related to vasomotor and respiratory activity. With this procedure the state of sympathovagal balance modulating sinus node pacemaker activity can be quantified in a variety of physiological and pathophysiological conditions. Changes in sympathovagal balance can be often detected in basal conditions, however a reduced responsiveness to an excitatory stimulus is the most common feature that characterizes numerous pathophysiological states. Moreover the attenuation of an oscillatory pattern or its impaired responsiveness to a given stimulus can also reflect an altered target function and thus can furnish interesting prognostic markers. The dynamic assessment of these autonomic changes may provide crucial diagnostic, therapeutic and prognostic information, not only in relation to cardiovascular, but also non-cardiovascular disease. As linear methodologies fail to provide significant information in conditions of extremely reduced variability (e.g. strenuous exercise, heart failure) and in presence of rapid and transients changes or coactivation of the two branches of autonomic nervous system, the development of new non-linear approaches seems to provide a new perspective in investigating neural control of cardiovascular system.
---
paper_title: Short communication: infrared thermography and visual examination of hooves of dairy cows in two stages of lactation.

paper_content:

Hooves of 16 lactating Holstein cows were examined twice for sole hemorrhages and underrun heels. Images of hooves were taken using infrared thermography to determine the temperatures of the coronary band and that of a control area above the coronary band. To adjust for skin (control) temperature, the difference (DeltaT) between the coronary band and the control area was calculated. Effects of stage of lactation, that is, <or=200 d in milk (DIM) vs. >200 DIM, on temperature of the coronary band, DeltaT, and visual abnormalities were determined. Temperatures of the coronary bands of cows were greater for cows <or=200 DIM (n = 17) than for cows (n = 15) in late lactation (25.5 +/- 1.3 vs. 21.0 degrees C). The DeltaT was also greater for cows <or=200 DIM compared with those >200 DIM (6.1 +/- 0.8 vs. 3.3 +/- 0.9 degrees C). The DeltaT was greater for lateral claws than for medial claws (5.2 +/- 0.6 vs. 4.2 +/- 0.6 degrees C). Chi-square analysis revealed that the frequency of sole hemorrhages in hind lateral claws was significantly higher for cows <or=200 DIM compared with those in late lactation. In contrast, underrun heel was more frequently observed among cows >200 DIM. Increased temperatures of the coronary band and DeltaT in early/midlactation coincided with increased incidence of sole hemorrhages, but not to incidences of underrun heels. Because higher hoof temperatures occurred in cows <or=200 DIM compared with cows later in lactation, measurement of hoof temperatures among cows in early lactation may be useful in monitoring hoof health.
---
paper_title: Daily variation in the udder surface temperature of dairy cows measured by infrared thermography: Potential for mastitis detection

paper_content:

The daily and within-day variation in udder temperature was monitored in dairy cows (n = 10) using infrared thermography (IRT). The initial assessment and prediction of udder surface temperature variation would hopefully form the basis for future development of an early detection method for mastitis. Our initial objective was to determine the magnitude and pattern of udder temperature variation. To accomplish this, we measured daily fluctuations in udder temperature and the influence of environmental factors upon these values in non-mastitic cows. Udder temperature rose significantly after an exercise period (P < 0.05). Within-day monitoring of udder temperature demonstrated there was a distinct circadian rhythm. Lag regression analysis showed that previous daily udder temperatures together with environmental temperature parameters could successfully predict current udder temperature with a high degree of accuracy. The variation between predicted and actual udder temperature was within the detectable rang...
---
paper_title: Implications of changes in core body temperature.

paper_content:

Dairy farmers and veterinarians have used body temperatures, most commonly rectal temperatures, to detect and manage febrile disease and changes in the state of cows (estrus and onset of calving) for many years. Mastitis, pneumonia, metritis, lameness, estrus, onset of parturition, heat stress, and subacute ruminal acidosis (SARA) are among the physiological conditions potentially correlated with body temperature that deviates from normal. Many new technologies have been introduced to measure body temperature of cattle at various locations, including rectum, ear (tympanic), vagina, reticulum-rumen, skin, and milk. While each location has its own advantages and disadvantages, temperature measurements at some of these locations can be automated for routine, frequent, and non-disruptive temperature recording. Systems for measurement of reticular temperature are available commercially. However, many factors other than the physiological conditions of interest affect reticular temperature. Among these are ambient temperature, food and water consumption, stage of lactation cycle, age, recumbency, activity level, stage of gestation, and of course, general health. The relationship between reticular and rectal temperatures appears to be relatively consistent, though the correlation is affected by time of season, housing system, and time of day. Reticular temperatures are affected by water intake, and substantially so for large volumes and extremely cold water; and dips in reticular temperature following water consumption must be considered when interpreting observations. Research is continuing to assess the ability of reticular temperature monitoring, perhaps in conjunction with other precision dairy farming tools, to allow earlier intervention with appropriate management. Success of early intervention will be the key to the ultimate success of any temperature monitoring technology.
---
paper_title: Monitoring the body temperature of cows and calves using video recordings from an infrared thermography camera

paper_content:

The aim of this study was to assess the variability of temperatures measured by a video-based infrared camera (IRC) in comparison to rectal and vaginal temperatures. The body surface temperatures of cows and calves were measured contactless at different body regions using videos from the IRC. Altogether, 22 cows and 9 calves were examined. The differences of the measured IRC temperatures among the body regions, i.e. eye (mean: 37.0 °C), back of the ear (35.6 °C), shoulder (34.9 °C) and vulva (37.2 °C), were significant (P < 0.01), except between eye and vulva (P = 0.99). The quartile ranges of the measured IRC temperatures at the 4 above mentioned regions were between 1.2 and 1.8 K. Of the investigated body regions the eye and the back of the ear proved to be suitable as practical regions for temperature monitoring. The temperatures of these 2 regions could be gained by the use of the maximum temperatures of the head and body area. Therefore, only the maximum temperatures of both areas were used for further analysis. The data analysis showed an increase for the maximum temperature measured by IRC at head and body area with an increase of rectal temperature in cows and calves. The use of infrared thermography videos has the advantage to analyze more than 1 picture per animal in a short period of time, and shows potential as a monitoring system for body temperatures in cattle.
---
paper_title: Effect of shearing on water turnover and thermobiological variables in German Blackhead mutton sheep

paper_content:

Current equations for estimating water requirements in sheep do not differentiate between shorn and unshorn sheep. Furthermore, the effect of shearing on thermoregulative responses in sheep has not been adequately studied under temperate environmental conditions. Therefore, the present study was conducted to investigate the effect of wool coverage on water turnover in relation to thermoregulation in sheep by using the deuterium dilution technique to predict total water intake before and after shearing. Physiological responses, such as water turnover, surface temperature, and rectal temperature, as well as drinking behavior of sheep were also evaluated. Fourteen nonlactating German Blackhead mutton ewes were randomly allocated into 2 groups: a control group (n = 7) that was already shorn, and a treatment group (n = 7) that was left unshorn (wool length: 10.6 ± 1.2 cm). Individual feed and water intakes were recorded throughout the experiment (d 1 to 71). Two weeks after measurements commenced (d 15), treatment sheep were shorn. Water intake was estimated twice for 2 consecutive weeks by using deuterium dilution techniques (d 1 to 15 and d 57 to 71). Ambient temperature (T(a)), relative humidity, and respiratory rate were measured daily, whereas BW, rectal and animal surface temperatures (using infrared thermography), and wool length were measured weekly. In the first 2 wk, when treatment sheep were unshorn, treatment and control ewes differed (P < 0.05) in DMI (52 ± 4 vs. 59 ± 4 g·kg(-0.75)·d(-1)), water intake (165 ± 17 vs. 134 ± 18 g·kg(-0.75)·d(-1)), respiratory rate (66 ± 5 vs. 31 ± 4 breath/min), rectal temperature (39.3 ± 0.2 vs. 38.8 ± 0.1°C), and surface temperatures (body side: 19.3 ± 0.3 vs. 24.5 ± 0.6°C; leg: 25.8 ± 2.4 vs. 27.4 ± 1.6°C). However, after shearing, these differences partly disappeared. The same trend in water intake between groups was confirmed using the isotope dilution technique. We found a significant relationship between T(a) and water intake, respiratory rate, and body surface temperatures. Even under temperate conditions (T(a) < 28°C), shearing significantly reduced core body temperature, water intake, and respiratory rate in German Blackhead mutton sheep, thus indicating heat stress in fleeced animals, which should be considered when determining the optimal shearing time in sheep as well as when estimating water requirements.
---
paper_title: Determination of the Cutaneous Temperature by Infrared Thermometry in Holstein Cows

paper_content:

The purpose of the study is to determine, by infrared thermometry, the cutaneous temperature in Holstein dairy cows and to obtain "the thermal maps" in cows. The meteorological data were provided by a Meteorological Station (Adcon Telemetry) and the temperature and humidity in the stable were determined using a psichrometer. The maximum -Temperature - Humidity Index on the pasture exceeded 72 (varying between 77 - 80) and in the stable varied from 68 to 70. The cutaneous temperatures were measured using an infrared thermometer (Oatkon).The cutaneous temperature determinations were made in Holstein dairy cows kept on pasture, compared to a group maintained in the stable, consisting of 30 cows per each group. The experiment on pasture was carried out in two stages. In the first stage the cows were exposed to direct solar radiation, and the cutaneous temperatures were measured after 30 minutes. In the second stage, the same cows were kept in shade provided by trees on the pasture and after a period of 30 minutes the cutaneous temperatures were determined. The differences of the cutaneous temperatures were significant depending on the colour of the skin of the cows exposed to solar radiation. On the non-pigmented body areas, the most reduced values were recorded at the extremities (32.22 ± 0.611 °C on the mouth) and the highest values were determined on the croup area (35.75 ± 0.707 °C). On the black body zones the temperature varied between 36.13 ± 0.838 oC at the mammilla and 41.26 ± 0.529 °C at the shoulder area. After performing this study we may conclude that the determination of the cutaneous temperatures may be an important parameter to indicate the heat stress in dairy cows exposed to solar radiation.
---
paper_title: Thermographic Eye Temperature as an Index to Body Temperature in Ponies

paper_content:

Infrared thermography (IRT) is a passive, remote, and noninvasive method of measuring surface temperatures. Select surface locations, such as the eye, could indicate body temperature. To investigate whether thermographic eye temperatures were associated with body temperatures and could be used to detect febrile ponies, we measured IRT eye temperatures, rectal temperatures, and implanted thermal microchip temperatures from 24 male ponies daily for 3 consecutive days. Information regarding distance of the pony from the IRT device, presence of direct sunlight during the measurement period, and ambient temperature were also collected. A multivariate linear regression analysis indicated that 60.41% of the variance in IRT was accounted for by rectal temperature, sunlight, and distance between the camera and the pony, with rectal temperature being the major contributor to variance (46.23%). Using a rectal temperature of >38.6°C (101.5°F) as the indicator of febrile status, sensitivity and specificity of the IRT device used to detect the febrile ponies were found to be 74.6% and 92.3%, respectively, when using the maximum IRT eye temperature per pony per day. In conclusion, IRT eye temperature could be a preliminary screening tool to determine whether a more time-consuming, labor–intensive, and invasive method (e.g., rectal temperature) is warranted for fever validation.
---
paper_title: Applications of thermal imaging in avian science

paper_content:

Thermal imaging, or infrared thermography, has been used in avian science since the 1960s. More than 30 species of birds, ranging in size from passerines to ratites, have been studied using this technology. The main strength of this technique is that it is a non-invasive and non-contact method of measuring surface temperature. Its limitations and measurement errors are well understood and suitable protocols have been developed for a variety of experimental settings. Thermal imaging has been used most successfully for research on the thermal physiology of captive species, including poultry. In comparison with work on mammals, thermal imaging has been less used for population counts, other than for some large bird species. However, more recently it has shown greater success for detection of flight paths and migration. The increasing availability and reduced cost of thermal imaging systems is likely to lead to further application of this technology in studies of avian welfare, disease monitoring, energetics, behaviour and population monitoring.
---
paper_title: Peripheral temperature drop in response to anticipation and consumption of a signaled palatable reward in laying hens (Gallus domesticus)

paper_content:

Abstract The present study describes effects of anticipation and consumption of a palatable reward on comb surface temperature. The purpose was to investigate temperature responses as a potential physiological indicator of positive emotional states in laying hens. A rise in body temperature in response to stimuli predictive of or during exposure to unpleasant events has been interpreted as evidence of emotions in mammals and avians. However, this phenomenon has so far only been studied during anticipation of or exposure to negative events; i.e. emotions of a negative valence. Infrared thermography was used to record potential alterations in comb surface temperature to a conditioned cue signaling a reward (mealworms) and during reward delivery. On average, comb temperature dropped 1.5 °C (95% CI: +/− 1.2 °C) after exposure to CS and consumption of reward (p ~ 0.0014) when initial comb temperature was above 30 °C. Such temperature drop indicates a peripheral vasoconstriction and has clear resemblances to emotional fever as seen during negative emotional states. Thus, we propose that a drop in peripheral temperature reflects emotional arousal more than emotional valence. Substantial temperature responses due to diet-induced thermogenesis were found, further emphasizing a cautious interpretation of altered comb temperature in studies of animal welfare.
---
paper_title: Eye temperature and heart rate variability of calves disbudded with or without local anaesthetic

paper_content:

The possibility that pain can be detected from changes in eye temperature and heart rate variability (HRV) during disbudding was examined in thirty calves, randomly assigned to four treatments: 1) sham handling (control), 2) local anaesthetic (LA, cornual nerve injection) and sham disbudded, 3) sham LA and disbudded, 4) LA and disbudded. During a 40 min sampling period, maximum eye temperature, behavior and HRV parameters were recorded continuously. One week later, twelve disbudded calves were injected with adrenocorticotrophic hormone (ACTH) or saline and maximum eye temperature was recorded. There was a rapid drop in eye temperature during the 5 min following disbudding without LA (P < 0.05). Eye temperature then increased and was higher than baseline over the remaining sampling period following both disbudding procedures (P < 0.001), a response which could not be explained by increased physical activity LA increased eye temperature prior to disbudding (P < 0.001). Heart rate increased (P < 0.001) during the 5 min following disbudding with and without LA, however, LF/HF ratio only increased during this time (P < 0.01) following disbudding without LA. Eye temperature did not change following ACTH, suggesting that hypothalamus–pituitary–adrenal axis (HPA) activity is not responsible for the changes in eye temperature following disbudding. The increase in LF/HF ratio following disbudding without LA suggests an acute sympathetic response to pain, which could be responsible for the drop in eye temperature via vasoconstriction. HRV and eye temperature together may be a useful non-invasive and more immediate index of pain than HPA activity alone.
---
paper_title: Relationship between vaginal and tympanic membrane temperature in beef heifers

paper_content:

Vaginal and tympanic membrane temperatures were simultaneously monitored in nine beef heifers. Data not associated with ear infections were characterized by respective vaginal and tympanic membrane temperatures of 38.81 and 38.58 °C. A close relationship between the two temperatures was indicated by a correlation of 0.77 and residual standard deviation of 0.29 °C. Key words: Cattle, radiotelemetry, thermoregulation, tympanic membrane, vagina
---
paper_title: Infrared temperature patterns of cow's body as an indicator for health control at precision cattle farming

paper_content:

Cows' infrared radiation temperature study was carried out at experimental cowshed (120 cows) of Estonian University of Life Sciences. Thermal image scanner Fluke TiS was used for obtaining 640×480 pixels thermal images with resolution of 0.1°C. The temperature distribution pattern of different parts of cow's body was estimated and analysed with SmartView software. Special attention was paid to udder, feet and areas with skin injuries. It was estimated that the temperature varies considerably at different parts of the body. Radiation temperature of healthy udder did not change considerably after milking. It means that automatic monitoring of udder temperature is possible not only in milking parlour or milking robot but also in other places where cows are identified. The udder thermograms enable to assess the milking hygiene, as the cleanliness of udder surface influences the measurement results, especially average temperature. The temperature of legs was lowest at the hoofs and highest at coronary band. Differences from this distribution may be used for estimation of leg disorders. Thermal images can be also successfully used for detection of skin injuries. Radiation temperature of injured and depilous locations was higher by several degrees than their surroundings. The study showed that thermal images analysis is promising method to be implemented at precision cattle farming.
---
paper_title: Avian maternal response to chick distress

paper_content:

The extent to which an animal is affected by the pain or distress of a conspecific will depend on its capacity for empathy. Empathy most probably evolved to facilitate parental care, so the current study assessed whether birds responded to an aversive stimulus directed at their chicks. Domestic hens were exposed to two replicates of the following conditions in a counterbalanced order: control (C; hen and chicks undisturbed), air puff to chicks (APC; air puff directed at chicks at 30 s intervals), air puff to hen (APH; air puff directed at hen at 30 s intervals) and control with noise (CN; noise of air puff at 30 s intervals). During each test, the hens' behaviour and physiology were measured throughout a 10 min pre-treatment and a 10 min treatment period. Hens responded to APH and APC treatments with increased alertness, decreased preening behaviour and a reduction in eye temperature. No such changes occurred during any control period. Increased heart rate and maternal vocalization occurred exclusively during the APC treatment, even though chicks produced few distress vocalizations. The pronounced and specific reaction observed indicates that adult female birds possess at least one of the essential underpinning attributes of empathy.
---
paper_title: Thermography in the assessment of equine lameness

paper_content:

Infrared thermography pictorially represents the surface temperature of an object. It is a noninvasive method for detecting superfi cial infl ammation and thus can be used in lameness diagnosis. Th ermography is prone to artifacts, and, consequently, this has led some people to doubt its clinical applicability. With experience and care in interpretation, thermography can be a useful method for lameness evaluation. Th e aim of this study was to present further clinical information about infrared thermal cameras and to compare the diagnostic yields of thermography, radiography, and ultrasonography. Forming the animal material of this study were 47 horses with lameness. Th e extremities of the horses were evaluated via thermal camera following clinical examination. Aft er this procedure, radiographic and ultrasonographic images were taken for the suspected region in all cases. Th e level of diagnosis with these techniques was scored and a comparison of the diagnostic methods was evaluated statistically. It was found that thermography can be a useful adjunct to lameness evaluation as part of integrated clinical and other imaging methods.
---
paper_title: Effect of temperature level on thermal acclimation in Large White growing pigs.

paper_content:

The effect of temperature level (24°C, 28°C, 32°C or 36°C) on performance and thermoregulatory response in growing pigs during acclimation to high ambient temperature was studied on a total of 96 Large White barrows. Pigs were exposed to 24°C for 10 days (days −10 to −1, P0) and thereafter to a constant temperature of 24°C, 28°C, 32°C or 36°C for 20 days. Pigs were housed in individual metal slatted pens, allowing a separate collection of faeces and urine and given ad libitum access to feed. Rectal (RT) and cutaneous (CT) temperatures and respiration rate (RR) were measured three times daily (0700, 1200 and 1800 h) every 2 to 3 days during the experiment. From day 1 to 20, the effect of temperature on average daily feed intake (ADFI) and BW gain (average daily gain, ADG) was curvilinear. The decrease of ADFI averaged 90 g/day per °C between 24°C and 32°C and 128 g/day per °C between 32°C and 36°C. The corresponding values for ADG were 50 and 72 g/day per °C, respectively. The 20 days exposure to the experimental temperature was divided in two sub-periods (P1 and P2, from day 1 to 10 and from day 11 to 20, respectively). ADFI was not affected by duration of high-temperature exposure (i.e. P2 v . P1). The ADG was not influenced by the duration of exposure at 24°C and 28°C groups. However, ADG was higher at P2 than at P1 and this effect was temperature dependent (+130 and +458 g/day at 32°C and 36°C, respectively). In P2 at 36°C, dry matter digestibility significantly increased (+2.1%, P P
---
paper_title: A Glucose Fuel Cell for Implantable Brain–Machine Interfaces

paper_content:

We have developed an implantable fuel cell that generates power through glucose oxidation, producing 3.4 μW cm(-2) steady-state power and up to 180 μW cm(-2) peak power. The fuel cell is manufactured using a novel approach, employing semiconductor fabrication techniques, and is therefore well suited for manufacture together with integrated circuits on a single silicon wafer. Thus, it can help enable implantable microelectronic systems with long-lifetime power sources that harvest energy from their surrounds. The fuel reactions are mediated by robust, solid state catalysts. Glucose is oxidized at the nanostructured surface of an activated platinum anode. Oxygen is reduced to water at the surface of a self-assembled network of single-walled carbon nanotubes, embedded in a Nafion film that forms the cathode and is exposed to the biological environment. The catalytic electrodes are separated by a Nafion membrane. The availability of fuel cell reactants, oxygen and glucose, only as a mixture in the physiologic environment, has traditionally posed a design challenge: Net current production requires oxidation and reduction to occur separately and selectively at the anode and cathode, respectively, to prevent electrochemical short circuits. Our fuel cell is configured in a half-open geometry that shields the anode while exposing the cathode, resulting in an oxygen gradient that strongly favors oxygen reduction at the cathode. Glucose reaches the shielded anode by diffusing through the nanotube mesh, which does not catalyze glucose oxidation, and the Nafion layers, which are permeable to small neutral and cationic species. We demonstrate computationally that the natural recirculation of cerebrospinal fluid around the human brain theoretically permits glucose energy harvesting at a rate on the order of at least 1 mW with no adverse physiologic effects. Low-power brain-machine interfaces can thus potentially benefit from having their implanted units powered or recharged by glucose fuel cells.
---
paper_title: Theory and Applications of Biotelemetry

paper_content:

In this study, biotelemetry and its evolution is explained in detail. Bioelectric and physiological variables could be measured by biotelemetry systems. The development of a biotelemetry system and its principal operation are presented. The components of a biotelemetry system are explained. Biomedical data has been telemetered through every medium between two sites by using a variety of modulated energy forms. Designing of the link between transmitter and receiver is described. Important factors in designing a backpack or implanted telemeter are explained. The main features of implanted biotelemetry units are determined. Single-channel and multichannel biotelemetry systems are defined. The types of telemetry, and a comparison thereof, are given. The power sources of biotelemetry systems and features of different power sources are explained. A survey of biotelemetry applications on humans and animals is presented and advantages of using biotelemetry systems are determined.
---
paper_title: Early detection and prediction of infection using infrared thermography

paper_content:

Early detection and/or prediction of disease in an animal is the first step towards its successful treatment. The objective of this study was to investigate the capability of infrared thermography as a non-invasive, early detection method for identifying animals with a systemic infection. A viral infection model was adopted using 15 seronegative calves whose body weight averaged 172 kg. Ten of these calves were inoculated with Type 2 bovine viral diarrhoea virus (strain 24515) and five were separately housed and served as uninfected controls. A simultaneous comparison of infrared characteristics in both infected and control animals was conducted over approximately 15 d. In addition, measures of blood and saliva cortisol, immunoglobulin A, blood haptoglobin and clinical scores were obtained. Infrared temperatures, especially for facial scans, increased by 1.5°C to over 4°C (P < 0.01) several days to 1 wk before clinical scores or serum concentrations of acute phase protein indicated illness in the infected...
---
paper_title: Comparison of rectal, microchip transponder, and infrared thermometry techniques for obtaining body temperature in the laboratory rabbit (Oryctolagus cuniculus).

paper_content:

This study compared rabbit rectal thermometry with 4 other thermometry techniques: an implantable microchip temperature transponder, an environmental noncontact infrared thermometer, a tympanic infrared thermometer designed for use on humans, and a tympanic infrared thermometer designed for use on animals. The microchip transponder was implanted between the shoulder blades; the environmental noncontact infrared thermometer recorded results from the base of the right pinna and the left inner thigh, and the tympanic infrared thermometer temperatures were taken from the right ear. Results from each technique were compared to determine agreement between the test modality and the rectal temperature. The practicality and reliability of the modalities were reviewed also. According to this study, the implantable microchip transponder measurements agreed most closely with the rectal temperature.
---
paper_title: Daily variation in the udder surface temperature of dairy cows measured by infrared thermography: Potential for mastitis detection

paper_content:

The daily and within-day variation in udder temperature was monitored in dairy cows (n = 10) using infrared thermography (IRT). The initial assessment and prediction of udder surface temperature variation would hopefully form the basis for future development of an early detection method for mastitis. Our initial objective was to determine the magnitude and pattern of udder temperature variation. To accomplish this, we measured daily fluctuations in udder temperature and the influence of environmental factors upon these values in non-mastitic cows. Udder temperature rose significantly after an exercise period (P < 0.05). Within-day monitoring of udder temperature demonstrated there was a distinct circadian rhythm. Lag regression analysis showed that previous daily udder temperatures together with environmental temperature parameters could successfully predict current udder temperature with a high degree of accuracy. The variation between predicted and actual udder temperature was within the detectable rang...
---
paper_title: Implications of changes in core body temperature.

paper_content:

Dairy farmers and veterinarians have used body temperatures, most commonly rectal temperatures, to detect and manage febrile disease and changes in the state of cows (estrus and onset of calving) for many years. Mastitis, pneumonia, metritis, lameness, estrus, onset of parturition, heat stress, and subacute ruminal acidosis (SARA) are among the physiological conditions potentially correlated with body temperature that deviates from normal. Many new technologies have been introduced to measure body temperature of cattle at various locations, including rectum, ear (tympanic), vagina, reticulum-rumen, skin, and milk. While each location has its own advantages and disadvantages, temperature measurements at some of these locations can be automated for routine, frequent, and non-disruptive temperature recording. Systems for measurement of reticular temperature are available commercially. However, many factors other than the physiological conditions of interest affect reticular temperature. Among these are ambient temperature, food and water consumption, stage of lactation cycle, age, recumbency, activity level, stage of gestation, and of course, general health. The relationship between reticular and rectal temperatures appears to be relatively consistent, though the correlation is affected by time of season, housing system, and time of day. Reticular temperatures are affected by water intake, and substantially so for large volumes and extremely cold water; and dips in reticular temperature following water consumption must be considered when interpreting observations. Research is continuing to assess the ability of reticular temperature monitoring, perhaps in conjunction with other precision dairy farming tools, to allow earlier intervention with appropriate management. Success of early intervention will be the key to the ultimate success of any temperature monitoring technology.
---
paper_title: Advances in Management of Poultry Production Using Biotelemetry

paper_content:

In this chapter, the authors review recent developments in the use of biotelemetry in poultry production. The chapter begins with an overview of advancements in biotelemetry and outlines the types of equipment that are commercially available as well as those adapted and developed by researchers primarily for use in farm animals. The authors then highlight the significant milestones achieved by the scientific community in using biotelemetry towards a more holistic poultry production guided by birds’ physiological responses to environmental stressors. In particular, the authors discuss efforts at the University of Georgia towards building the next generation closed-loop poultry environmental controller which responds directly and in real-time to physiological needs of the birds. Biotelemetry is defined as the remote detection and measurement of physiological, bioelectrical, and behavioral variables to monitor function, activity, or condition of conscious unrestrained humans or animals. This encompasses a broad range of techniques of varying invasiveness including video monitoring, non-contact thermometry, radio tracking and the use of internally or externally mounted remote sampling systems (Morton et al., 2003). Biotelemetry is not a new concept and it was first introduced by Einthoven in 1903 when he measured the electrocardiogram using immersion electrodes remotely connected to a galvanometer via telephone lines (Cromwell et al., 1973, as cited in Hamrita et al., 1998). In later years, NASA played a big role in the advancement of biotelemetry by using it to transmit astronaut biomedical data such as heart rate and body temperature to earth. In (N. F. Guler & Ubeyli, 2002), the authors provide a detailed history of early uses and developments of biotelemetry. Biotelemetry consists of sensing the variable of interest from the animal using miniature sensors or transducers. These can be placed on the animal, ingested by the animal, or implanted inside the animal by means of injection or surgery. The output of the sensor or transducer is modulated to a form which can be transmitted wirelessly over a distance from the animal to a receiver using an embedded transmitter. The received signal is demodulated and the measured variable extracted through proper signal conditioning and calibration by the data acquisition system. Biotelemetry data has been transmitted through every medium including air, vacuum, water, and biologic tissue using a variety of modulating carriers such as electromagnetic waves (especially at radiofrequencyhence the name radiotelemetry), light, and ultrasound (N. F. Guler & Ubeyli, 2002). By far the most common carriers of biotelemetry data are radio waves. Due to the proliferation of biotelemetry in recent years, the Federal
---
paper_title: A Review of Wireless Sensor Technologies and Applications in Agriculture and Food Industry: State of the Art and Current Trends

paper_content:

The aim of the present paper is to review the technical and scientific state of the art of wireless sensor technologies and standards for wireless communications in the Agri-Food sector. These technologies are very promising in several fields such as environmental monitoring, precision agriculture, cold chain control or traceability. The paper focuses on WSN (Wireless Sensor Networks) and RFID (Radio Frequency Identification), presenting the different systems available, recent developments and examples of applications, including ZigBee based WSN and passive, semi-passive and active RFID. Future trends of wireless communications in agriculture and food industry are also discussed.
---

Title: A Review of Methods to Measure Animal Body Temperature in Precision Farming
Section 1: Introduction
Description 1: Introduce the importance of precise and continuous monitoring of physiological parameters to ensure the health and well-being of animals in modern agricultural practices.

Section 2: About Homeothermy
Description 2: Explain thermoregulation, the processes of heat production and dispersal, and the factors influencing body temperature in animals.

Section 3: Contribution of Technological Progress
Description 3: Discuss advancements in technology for measuring body temperature and their benefits for improving data accuracy and reducing animal stress.

Section 4: Definition of Temperature Zone Measurements
Description 4: Define body core, mid-peripheral, and peripheral temperature measurement zones and their importance in understanding physiological phenomena and environmental interactions.

Section 5: Technical Section: the Most Common Systems to Measure Temperature Continuously without Restraining the Subject
Description 5: Provide an overview of the main types of sensors used for continuous temperature measurement, comparing their advantages and disadvantages.

Section 6: Contact Measurement Media
Description 6: Detail how thermocouples and thermistors work, their applications, and the importance of calibration and accuracy in temperature measurement.

Section 7: No-contact Measurement Media
Description 7: Explain the principles of infrared technology for temperature measurement, its applications, and how environmental factors affect its accuracy.

Section 8: Discussion about the Different Methods to Measure Remote Temperature
Description 8: Compare the benefits and limitations of contact and no-contact temperature measurement methods, considering their suitability for different research purposes.

Section 9: Temperature Measurement with Non-Invasive Contact Sensors
Description 9: Discuss methods and studies using non-invasive contact sensors for deep core temperature measurement, their limitations, and their applications in various animal species.

Section 10: Temperature Measurement with Invasive Contact Sensors
Description 10: Describe the use of invasive contact sensors, their placement, the importance of surgical precision, and the conditions they are used to monitor.

Section 11: Temperature Measurement with Non-Invasive No Contact Sensors
Description 11: Review the use of infrared technology for non-contact temperature measurement, its applications, and the importance of strict standards for reliable data.

Section 12: Discussion
Description 12: Summarize key findings, the importance of choosing appropriate measurement devices, and the collaboration needed for future advancements in remote temperature measurement technologies.

Section 13: Conclusion
Description 13: Conclude by emphasizing the potential of new technologies for livestock monitoring, their impact on early disease detection, and the ongoing innovation in the field of precision farming.