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A relatively noninvasive method consisting of a face mask sampling device, solid-phase microextraction (SPME) fibers, and a gas chromatography-mass spectrometry (GC-MS) for the identification of volatile organic compounds (VOCs) in bovine breath was developed. Breath of three morbid steers with respiratory tract infections and three healthy steers were sampled seven times in 19 days for 15 min at each sampling. The breath VOCs adsorbed on the divinylbenzene (DVB)-Carboxen-polydimethyl siloxane (PDMS) 50/30 microm SPME fibers were transported to a laboratory GC-MS system for separation and identification with an in-house spectral library of standard chemicals. A total of 21 VOCs were detected, many of them for the first time in cattle breath. Statistical analyses using Chi-square test on the frequency of detection of each VOC in each group was performed. The presence of acetaldehyde (P < or = 0.05) and decanal (P < or = 0.10) were associated more with clinically morbid steers while methyl acetate, heptane, octanal, 2,3-butadione, hexanoic acid, and phenol were associated with healthy steers at P < or = 0.10. The results suggest that noninvasive heath screening using breath analyses could become a useful diagnostic tool for animals and humans.

Non-invasive sampling and chemical analysis of breath gases could provide valuable information related to health and well-being. Breath gases are indicators of metabolic end products. The objective of this research was to design, assemble and test a new facemask-like device for on-site bovine breath sample collection with solid-phase microextraction (SPME). The new device consists of a cylindrical container, a sealing membrane for enclosure of nostrils and mouth of cattle, a system of filters and one-way valves, and sampling ports sealed with septa facilitating insertion of air sampling probes inside the device. An experiment was conducted to examine the feasibility of detecting volatile organic compounds (VOCs) exhaled by calves using this device. Solid-phase microextraction was used to collect rapid on-site breath samples. Divinylbenzene/Carboxen/polydimethylsiloxane (DVB/Carboxen/PDMS) 50/30 μm and PDMS 100 μm SPME fibres and sampling times ranging from 5 to 15 min were used. The SPME-based samples were sealed and transported to the laboratory and analysed with chromatography–mass spectrometry (GC–MS). Acetone, methyl ethyl ketone, toluene, tetradecane, pentadecane, nonanal and decanal were identified in cattle breath. A simple sampling system, combined with SPME-based sampling and analysis with GC–MS was very useful for fast collection and detection of bovine breath gases. The DVB/Carboxen/PDMS 50/30 μm fibre coating, sealing caps, and refrigeration worked well for retaining compounds found in breath samples. Solid-phase microextraction was also valuable for detection of residual VOCs in the breath sampling device that resulted in optimisation of cleaning procedures. The device can be easily adapted for other animals by adjusting the size of the cylindrical container and/or by replacing the sealing membrane with more suitable opening.

Weanling female Spanish goats ( n =36) were randomly allotted to four treatment groups (each group, n =9): principal dust group with antibiotic; principal dust group without antibiotic; control group with antibiotic; and control group without antibiotic. The principals were exposed to twenty-two 4 h dust treatments in a closed tent. Dust treatments occurred as follows: one dust treatment, 18-day rest, seven daily dust treatments, 7-day rest, seven daily dust treatments, 7-day rest, and seven daily dust treatments. All principals and six controls were euthanatized and necropsied at the end of the experiment. There was an interaction between dust and tilmicosin antibiotic for feed intake and average daily gain following the first dust treatment. The interaction occurred because control goats not exposed to dust nor receiving tilmicosin protection had lower ( P P P ≤0.0003). Four hours ( P ≤0.0016) after dust treatment, the mean rectal temperature of the two principal groups was higher than the controls. On the first 7-day dust treatment series there was a significant ( P ≤0.0006) difference between the groups. The mean rectal temperatures of the two principal groups at 8 h on day 1 were significantly ( P ≤0.02) higher than the control groups. On the second 7-day dust treatments, there were no significant differences in mean rectal temperature between the groups. On the third 7-day treatment series there were significant ( P ≤0.0001) differences among the four groups. On the first day of the dust treatment series, at 8 h, the trend of the principal groups’ mean rectal temperature was higher than the controls. It appears that repeated endotoxin/dust exposures induces a state of tolerance for increased rectal temperatures that are characteristic after one dust exposure. There were no gross observable differences between the controls and principal respiratory tracts. The following histologic changes were observed in the principal goats: a mild alveolar septal hypercellularity, moderate multifocal airway exudation of neutrophils and macrophages containing foreign particulate material, and there was a marked increase in bronchial associated lymphoid tissue compared to controls. The diagnosis was mild acute exudative bronchointerstital pneumonia. No significant microscopic lesions were observed in the control goats.

Objective—To determine the clinical, clinicopathologic, and histologic effects of aerosolized feedyard dust that contains natural endotoxins on adult sheep. Animals—Eighteen 3-year-old Saint Croix sheep. Procedure—A prospective randomized controlled study was conducted. There were 2 treatment groups (dust-endotoxin group, n = 9; control group, 9). Aerosolized feedyard dust was provided continuously during a 4-hour period for each application (once in week 1, 3 times in week 2, and 7 times in week 3) to sheep in a semiairtight tent. All sheep were euthanatized and necropsied 8 hours after the treatment group received the last dust treatment. Variables measured before and after each dust treatment were rectal temperature, total WBC count, and concentrations of fibrinogen and haptoglobin. Results—Mean amount of dust administered during each treatment was 451 g/4 h. Filter collection indicated 51 mg of dust/m3 and 7,423 ng of endotoxin. Mean rectal temperature at 8 hours (40.4 C) and mean WBC counts 12 and 24 hours after dust treatment were significantly higher for the treated group than the means of the respective variables for the control group. Similar responses were observed with repeated dust-endotoxin treatments; however, with each subsequent treatment, there was a diminished response. Sheep in the treatment group had generalized alveolar septal thickening and hypercellularity. Conclusion and Clinical Relevance—Feedyard dust induced a temporary febrile response and leukocytosis in sheep in the treatment group. Exposure to dust that contains endotoxins may be a stressor preceding acute infectious respiratory tract disease of marketed sheep. (Am J Vet Res 2002;63:28–35)

Objective—To determine the effect of transportation stress on serum concentrations of oxidative stress biomarkers of calves.Animals—105 crossbred beef steer calves (mean [± SD] body weight, 207 ± 21.2 kg).Procedure—Calves were assembled at 1 location in Tennessee, and pretransit (day –3) blood samples were collected. Calves were allotted randomly by body weight into 2 groups. Calves were transported 1,930 miles to a feedlot in Texas, and 1 group received tilmicosin phosphate (33 µg/kg, SC) upon arrival. Calves were weighed and blood samples collected on the day of arrival (day 1) and on days 15, 22, and 28. Calves were scored daily for signs of bovine respiratory disease (BRD). Serum total antioxidant capacity (TACA) and serum malondialdehyde (MDA) concentrations were determined.Results—Transportation stress significantly decreased mean serum TACA concentrations (from 147 ± 31.2 U/mL to 133 ± 20.1 U/mL) and significantly increased serum MDA concentrations (from 10.9 ± 18.3 µg/mL to 30.2 ± 50.5 µg/mL). Calves that died had a 43% increase in serum MDA concentration on day 1, compared with calves that lived (42.2 ± 67.0 µg/mL vs 29.4 ± 49.4 µg/mL, respectively). Calves that had ≥ 3 episodes of BRD had 2-fold higher serum MDA concentrations on day 1 than healthy calves. Tilmicosintreated calves had a 20.8% significantly greater average daily gain and significantly greater serum TACA concentration than nontreated calves on day 28.Conclusions and Clinical Relevance—Transportation stress increases serum concentrations of oxidative stress biomarkers that are related to episodes of BRD and mortality in calves. (Am J Vet Res2004;65:860–864)

The objective was to determine whether the inhalation of large quantities of feedyard dust predisposed the animals to pulmonary bacterial proliferation. Two control groups, C1 and C2, did not receive dust treatments, and two principal groups (P1 and P2) received a total of 14 dust treatments each. The C1 and P1 groups of goats each received a transthoracic challenge of live Mannheimia haemolytica (4 x 10(6) colony forming units, CFU) The C2 and P2 groups of goats each received a transthoracic challenge of live Pasteurella multocida (1.0 x 10(6) CFU/goat). The results showed that dusted animals had fever when compared with non-dusted controls. In addition, dusted animals demonstrated a leukocytosis with neutrophilia after the first dust treatment that was not sustainable. Finally, dusted animals demonstrated pulmonary clearance of two potential bacterial pathogens that was not significantly different from that shown by control (not dusted) animals.

A new method for rapid sampling and qualitative characterization of the headspace gases of closed in vitro cultures using solid phase microextraction (SPME) was evaluated for ruminal fluid and ruminal fluid with feed containing a feed additive. Gas sample collection was achieved by exposing a DVB/Carboxen/PDMS 50/30 .m SPME fiber to the headspace of cultures for 1 min every hour. This was followed by immediate analysis on a GC–MS and then reuse of the SPME fiber. Acetic, propionic, isobutyric, butyric, isovaleric, valeric, and hexanoic acids and toluene, dimethyl disulfide, and pentadecane were identified in the headspace. SPME technology facilitated rapid sampling and immediate analysis with a GC–MS to identify specific end products of microbial digestion. A SPME–based approach could serve as a new method for the characterization of ruminal fermentation end products and testing effects of feed additives on the formation of end products.

A face mask sampling device, DVB/Carboxen/PDMS 50/30 µm solid phase microextraction (SPME) fibers, and a gas chromatograph with a mass spectrometer detector (GCMS) were used for sampling and analysis of volatile organic compounds (VOCs) in bovine breath. Breath of 3 morbid steers with respiratory tract infections and 3 healthy steers were sampled 7 times in 19 days for 15 min at each sampling. A total of 21 VOCs were detected, many of them for the first time in cattle breath. Preliminary statistical analyses using Chi-square Test on the frequency of detection of each VOC in each group was performed. The presence of acetaldehyde (P = 0.05) and decanal (P = 0.10) were associated more with clinically morbid steers while methyl acetate, heptane, octanal, 2,3-butadione, hexanoic acid, and phenol were associated with healthy steers at P = 0.1. The results suggest that noninvasive heath screening using breath analyses could become a useful diagnostic tool for detecting sick and healthy cattle.

An experiment was conducted to examine the feasibility of detecting unique volatile organic biomarkers exhaled by healthy and morbid heifer calves on-site using noninvasive sampling with solid phase microextraction (SPME) and analysis with gas chromatography-mass spectrometry (GC-MS). Two heifers were selected on the bases of health status and were sampled from 5 to 15 min with a special facemask sampling system using DVB/Carboxen/PDMS 50/30 µm and PDMS 100 µm SPME fibers. The samples were sealed and transported to the laboratory and analyzed with ion trap GC-MS. Acetone, methyl ethyl ketone, toluene, pentadecane, and nonanal were detected in cattle breath. Tetradecane and decanal were detected in the breath of the sick heifer only. Detector responses to breath VOCs were generally higher for the morbid heifer than the healthy one. Longer extraction time (15 min) resulted in larger detector responses and greater number of compounds detected compared to the short sampling time (5 min). A simple sampling system, combined with SPME-based sampling and analysis with GC-MS was very useful for the detection of bovine breath and ruminal gases. DVB/Carboxen/PDMS 50/30 µm coating, Teflon caps, and sample refrigeration worked well for sample preservation and retention of compounds found in breath samples. SPMEbased sampling of animal breath has the potential of being used as a rapid, non-invasive on-site diagnostic and research tool for cattle producers, veterinarians, and researchers.