The non-invasive and automated detection of bovine respiratory disease onset in receiver calves using infrared thermography

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.     

The use of infrared thermography as an early indicator of bovine respiratory disease complex in calves

Bovine respiratory disease (BRD) complex causes considerable distress to domestic livestock and economic hardship to the beef industry. Furthermore, the resulting extensive use of antimicrobial treatments is a growing concern from the perspective of facilitating antibiotic resistant microbes. The earlier detection of BRD would enable an earlier, more targeted treatment regime and earlier isolation of infected individuals. The objective of the present study was to investigate the use of non-invasive infrared thermography in the early detection of BRD in cattle. Studies were conducted on 133 head of weaned calves. Data demonstrated that infrared thermography was able to identify animals at early stages of illness, often several days to over one week before clinical signs were manifest. Data indicated that 4-6 days prior to the onset of clinical symptoms of BRD, greater positive and negative predictive values and test efficiency for infrared thermography (80%, 65% and 71%, respectively) compared to the industry standard practice of clinical scoring (70%, 45% and 55%, respectively).     

Detection of foot-and-mouth disease virus infected cattle using infrared thermography

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 °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 °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.     

Relationship between mean body surface temperature measured by use of infrared thermography and ambient temperature in clinically normal pigs and pigs inoculated with Actinobacillus pleuropneumoniae

OBJECTIVE: To determine the relationship between ambient temperature and mean body surface temperature (MBST) measured by use of infrared thermography (IRT) and to evaluate the ability of IRT to detect febrile responses in pigs following inoculation with Actinobacillus pleuropneumoniae. ANIMALS: 28 crossbred barrows. PROCEDURES: Pigs (n = 4) were subjected to ambient temperatures ranging from 10 to 32 C in an environmental chamber. Infrared thermographs were obtained, and regression analysis was used to determine the relationship between ambient temperature and MBST. The remaining pigs were assigned to groups in an unbalanced randomized complete block design (6 A pleuropneumoniae-inoculated febrile pigs [increase in rectal temperature > or = 1.67 C], 6 A pleuropneumoniae-inoculated nonfebrile pigs [increase in rectal temperature < 1.67 C], and 12 noninoculated pigs). Infrared thermographs and rectal temperatures were obtained for the period from 2 hours before to 18 hours after inoculation, and results were analyzed by use of repeated-measures ANOVA. RESULTS: A significant linear relationship was observed between ambient temperature and MBST (slope, 0.40 C). For inoculated febrile pigs, a treatment X method interaction was evident for rectal temperature and MBST, whereas inoculated nonfebrile pigs only had increased rectal temperatures, compared with noninoculated pigs. A method X time interaction resulted from the longer interval after inoculation until detection of an increase in MBST by use of IRT. CONCLUSIONS AND CLINICAL RELEVANCE: Infrared thermography can be adjusted to account for ambient temperature and used to detect changes in MBST and radiant heat production attributable to a febrile response in pigs.     

In vitro migration responses of neutrophils from cows and calves

The directional (chemotactic) and random migration activities of neutrophils from cows and newborn and 2-week-old calves were determined by use of the chemotaxis-under-agarose assay. Blood samples were stored for 2, 24, or 48 hours and at 4 or 25 C before testing. During the assay, cells were incubated at 17, 27, or 37 C. The assay was found suitable for testing the directional and random migration activities of neutrophils from cattle. Directional migration of neutrophils was diminished (P less than or equal to 0.05) when cells were incubated at 17 or 27 C, compared with data from incubation at 37 C. Random migration of neutrophils was unaffected by test incubation temperature. Significant (P less than or equal to 0.05) differences were found between cows and calves regarding the percentage number and viability and the directional and random migration activities of neutrophils. Neutrophils from cows were adversely affected to a greater extent by prolonged sample storage times or low storage temperature than were neutrophils from calves. Results indicate that a sample storage time of up to 24 hours, a sample storage temperature of 25 C, and a test incubation temperature of 37 C provided optimal conditions for testing the migratory activities of neutrophils from cattle.     

Comparison of body temperature in cats using a veterinary infrared thermometer and a digital rectal thermometer

The purpose of this study was to determine if the temperatures obtained using a veterinary infrared (IR) thermometer agreed with a digital rectal thermometer in a group of research cats, half of which had transient fevers. The thermometers were weakly correlated (r=0.62). The mean difference was 0.13 degrees F (0.07 degrees C), and the limits of agreement were 2.6 degrees F (1.43 degrees C) and -2.5 degrees F (-1.36 degrees C), which were unacceptable for clinical purposes. The results of this study indicate that, while the IR thermometer was easy to use, it cannot be used interchangeably with the rectal thermometer.     

Milking frequency affects the circadian body temperature rhythm in dairy cows

The objective of this study was to investigate milking frequency as a potential stressor in Holstein–Friesian dairy cows managed in a pastoral farming system. The circadian body (vaginal) temperature rhythm was measured in cows milked twice-a-day (2x) or once-a-day (1x) in two experiments. The first experiment was conducted at peak lactation (50 ± 11 days in milk, DIM) and the second in response to a transition from 2x to 1x milking at mid-lactation (153 ± 21 DIM). At peak lactation, body temperature was continuously recorded for seven days in 40 dairy cows, milked either 2x (two groups, n = 10 per group) or 1x (two groups, n = 10 per group) from the time of calving. At mid-lactation, 60 dairy cows were milked either 2x (four groups, n = 5 per group), 1x (four groups, n = 5 per group) or switched from 2x to 1x on the afternoon of 156 DIM (2x:1x, four groups, n = 5 per group). Body temperature was measured in three of the five cows per group (36 cows in total) for 10 days from 153 to 162 DIM. Milk yield and total grazing time (Experiment 2 only) were recorded in all cows. At peak lactation cows milked 2x had a higher (P ≤ 0.051) mean body temperature between 1600 and 0000 h than 1x cows (38.6 vs. 38.4 °C; SED = 0.03 °C). At mid-lactation, mean body temperature was also elevated between 1600 and 2000 h in 2x cows compared to 1x cows (2x: 38.6 °C, 1x:38.4 °C, SED = 0.04 °C; P < 0.001) and tended (P = 0.083) to be higher in 2x cows between 2000 and 0000 h. On the day the milking frequency was switched from 2x to 1x (156 DIM), mean body temperature still tended to be higher (P = 0.087) between 1600 and 2000 h in cows continuing on 2x compared with 2x:1x and 1x cows. Body temperature in 2x:1x cows on 157 DIM was lower than 2x cows and similar to that of 1x cows, but there was no consistent effect of milking frequency on body temperature from 158 to 162 DIM. Cows milked 2x had a higher daily milk yield than 1x cows at peak lactation and at mid-lactation (peak lactation 2x: 28.1 ± 5.1, 1x: 24.5 ± 4.7 kg milk per day). Time spent grazing between 1600 and 2000 h was initially at least 22 min higher (P = 0.031) in 1x cows than in 2x:1x and 2x cows on 153 DIM but there were no differences (P ≥ 0.107) in the remaining days of the trial. Milk yield in 2x:1x cows declined rapidly on 156 DIM to be lower (P < 0.001) than both 2x and 1x cows but from 157 DIM began to follow the same pattern as 1x cows. In conclusion, milking frequency had an effect on the circadian body temperature rhythm, particularly in the late afternoon and evening. There was a decline in body temperature from 1600 h if milking frequency was reduced, but this change was not explained by treatment differences in time spent grazing during the same period. The alterations in the circadian body temperature rhythm with milking frequency were likely due to differences in metabolic activity and internal heat production associated with locomotor activity and relative milk production rather than physiological stress per se.     

Season and physiological status affects the circadian body temperature rhythm of dairy cows

The circadian body (vaginal) temperature rhythm was measured in 36 dairy cows: Holstein–Friesian (HF, n = 12), Jersey (J, n = 12) and their crossbreed, Holstein–Friesian × Jersey (HF × J, n = 12) at six different periods (5-7 days in duration) during the year that could potentially be a seasonal and physiological stressor. These were a) early winter (late pregnancy), (b) early spring (early lactation), (c) late spring (before mating at mid-lactation), (d) early summer (after mating at mid-lactation), (e) late summer (late lactation, early pregnancy) and, (f) early autumn (drying-off at the end of lactation, mid-pregnancy). Live weight and body condition score was recorded on the first day of each measurement period. Live weight differed (P < 0.001) with breed with HF cows heaviest and J cows lightest (HF: 525 ± 51, HF × J: 456 ± 56, J: 401 ± 30 kg). HF cows tended (P = 0.099) to have a higher body condition than either J or HF × J cows although the overall change in body condition during the experiment was similar (P = 0.961) amongst breeds. The circadian body temperature rhythm differed markedly between each measurement period, being flatter and having a less prominent morning nadir and afternoon peak during early winter compared to spring and summer. The timing of peak body temperature was 4-5 h earlier in early autumn in HF and HF × J cows relative to J cows. There was no breed difference (P ≥ 0.162) in daily mean body temperature except for a tendency (P = 0.075) for mean body temperature to be moderately higher in J cows (38.5 °C) during late summer compared to HF and HF × J cows (38.4 °C), primarily due to an increase (P = 0.001) in daily minimum body temperature (38.0 vs. 37.8 °C). The daily range of oscillation (maximum–minimum) in the body temperature rhythm was highest during late summer, particularly in HF and HF × J cows. Minimum body temperature was also higher (P = 0.033) for J cows than HF and HF × J cows during early autumn (37.9 vs. 37.8 °C). In conclusion, season and physiological status of cattle had a profound effect on the circadian body temperature rhythm but there was little difference between the breeds of dairy cows studied.     

Stimulation and analysis of the immune response in calves from vaccinated pregnant cows

The effect of vaccinating pregnant cows with an inactivated vaccine against Mannheimia haemolytica, BRSV and PI3V infections on selected immune responses in their offspring was examined. Blood samples were collected weekly for 12 weeks from six newborn calves from each of vaccinated (experimental) and unvaccinated (control) dams. Specific antibodies to M. haemolytica, BRSV and PI3V and mean values of IgA, IgG concentrations were significantly higher in the experimental calves compared with the controls. However, specific antibody titres to adenovirus type 3, BHV1 and BVDV in the experimental calves had constant levels while the control group levels changed. The IgM, Hp and SAA concentrations generally increased until week 8 in the experimental group, but the control group titres became higher after week 9. This study demonstrates that specific immunisation of cows pre-partum significantly stimulated parameters associated with immunity and it also controlled the acute phase response intensity in their offspring. Therefore the vaccination of dams may provide additional antibody protection against infection to their offspring.     

Pharmacokinetics of sulphamethoxazole in calves and cows

Summary

The kinetics of sulphamethoxazole (SMZ) in plasma and milk, and its metabolism, protein binding and renal clearance were studied in three newborn calves and two dairy cows after intravenous administration. SMZ was predominantly acetylated; no hydroxy and glucuronide derivatives could be detected in plasma and urine. Age‐dependent pharmacokinetics and metabolism of SMZ were observed. The plasma concentration‐time curves of the N₄‐acetyl metabolite in the elimination phase were parallel to those of the parent drug; the N₄‐acetyl metabolite plasma percentage depended on age and ranged between 100% (new‐born) to 24.5% (cow). SMZ was rapidly eliminated (elimination half‐lives: 2.0–4.7 h) and exhibited a relatively small distribution volume (V_Darea: 0.44–0.57 l/kg). SMZ was excreted predominantly by glomerular filtration, while its N₄‐acetyl metabolite was actively eliminated by tubular secretion.     

Infrared thermography relationship between the temperature of the vulvar skin,ovarian activity,and pregnancy rates in Braford cows

Tropical Animal Health and Production - The objective of this study was to compare the presence of ovarian activity and pregnancy rates to temperature variation at the vulvar skin measured by...     

Pharmacokinetics of sulphamethoxazole in calves and cows

The kinetics of sulphamethoxazole (SMZ) in plasma and milk, and its metabolism, protein binding and renal clearance were studied in three newborn calves and two dairy cows after intravenous administration. SMZ was predominantly acetylated; no hydroxy and glucuronide derivatives could be detected in plasma and urine. Age-dependent pharmacokinetics and metabolism of SMZ were observed. The plasma concentration-time curves of the N4-acetyl metabolite in the elimination phase were parallel to those of the parent drug; the N4-acetyl metabolite plasma percentage depended on age and ranged between 100% (new-born) to 24.5% (cow). SMZ was rapidly eliminated (elimination half-lives: 2.0-4.7 h) and exhibited a relatively small distribution volume (VDarea: 0.44-0.57 l/kg). SMZ was excreted predominantly by glomerular filtration, while its N4-acetyl metabolite was actively eliminated by tubular secretion.     

Usefulness of infrared thermometry in determining body temperature in mice

The rectal temperature obtained using a standard electronic thermometer was compared with ear, back skin, tail skin, and sole skin temperatures obtained using an infrared thermometer in B6C3F1 mice. Using both methods, we investigated baseline temperatures, diurnal and 2-week variations in temperatures, and ethanol-induced hypothermia in these body locations. Ear and back temperatures were shown to be close to and consistent with rectal temperatures in various situations, and measured temperatures at these sites were almost constant, with very similar diurnal variation. Conversely, tail and sole temperatures were lower and much more variable. These results indicate that ear and back skin temperatures obtained using a convenient and non-invasive infrared thermometer are as reliable, and should be safer and less stressful to animal subjects, compared to standard rectal temperature measurements.