畜禽疾病尤其是人畜共患病会威胁人类和动物的健康,也会影响社会和经济发展,导致食品短缺.在密集型生产系统中,动物的疾病无法得到有效的监控,而技术可以为密切监测和生物监视提供解决方案,走向商业性应用市场的红外热成像正成为动物疾病的有效监控监测设备,在确保人类健康和食品安全方面发挥着积极的作用.
This study investigated the effect of milk allowance on the suitability of behavioural and physiological responses, individually and in combination, as early disease indicators. A total of 120 heifer calves were assigned into a 5 L/ d or 10 L/d milk allowance treatment group. Daily health checks were conducted to determine when calves presented clinical signs of neonatal calf diarrhoea (NCD). Automated calf feeders recorded milk feeding behaviour, and infrared cameras automatically recorded eye and cheek temperatures. Accelerometers recorded lying behaviour, and water drinking behaviour was recorded using an automated water system and video observations. Respiration rate was recorded once per day by counting flank movements. Calves were used as their own controls, with data analysed relative to the day of clinical identification (d 0). Based on changes which occurred over the 6 days prior to clinical signs of disease (across d-6 to 0), typically, feeding behaviours only changed significantly for calves on the 10 L/d milk allowance with an increase in total (P < 0.001) and rewarded visits to the feeder (P = 0.013), and a decrease in milk consumption (P = 0.011). Infrared temperatures only changed significantly prior to clinical signs for calves on the 5 L/d milk allowance, with a decrease in eye (P = 0.013) and cheek (P = 0.006) temperatures. Regardless of milk allowance, lying time (P = 0.028, 5L/d; P = 0.011, 10 L/d), number of lying bouts (P < 0.001, 5 L/d; P = 0.007, 10 L/d), and average bout duration (P < 0.001, 5 L/d; P = 0.002, 10 L/d), changed significantly prior to clinical signs. The only significant change in water drinking behaviour prior to clinical signs was an increase in total trough visit duration for calves on the 5 L/d milk allowance (P = 0.029). Respiration rate showed no significant change prior to clinical signs regardless of milk allowance. For calves on the 10 L/d and 5 L/d milk allowances, the most suitable indicator of disease was the total number of visits to the feeder (P < 0.001) and the number of lying bouts (P < 0.001), respectively. Regardless of milk allowance, combinations of feeding and lying behaviours, and additionally infrared temperatures in the case of calves on the 5 L/d milk allowance, provided the strongest composite indicators of disease. Overall, results suggest milk allowance can influence the suitability of behavioural and physiological responses as early disease indicators. Milk allowance should be considered when determining which measures will act as the optimum indicator/s when developing and implementing algorithms into automated on-farm systems for disease detection.
As the reliance upon automated systems in the livestock industry increases, technologies need to be developed which can be incorporated into these systems to monitor animal health and welfare. Infrared thermography (IRT) is one such technology that has been used for monitoring animal health and welfare and, through automation, has the potential to be integrated into automated systems on-farm. This study reports on an automated system for collecting thermal infrared images of calves and on the development and validation of an algorithm capable of automatically detecting and analysing the eye and cheek regions from those images. Thermal infrared images were collected using an infrared camera integrated into an automated calf feeder. Images were analysed automatically using an algorithm developed to determine the maximum eye and cheek (3 × 3-pixel and 9 × 9-pixel areas) temperatures in a given image. Additionally, the algorithm determined the maximum temperature of the entire image (image maximum temperature). In order to validate the algorithm, a subset of 350 images analysed using the algorithm were also analysed manually. Images analysed using the algorithm were highly correlated with manually analysed images for maximum image (R2 = 1.00), eye (R2 = 0.99), cheek 3 × 3-pixel (R2 = 0.85) and cheek 9 × 9-pixel (R2 = 0.90) temperatures. These findings demonstrate the algorithm to be a suitable method of analysing the eye and cheek regions from thermal infrared images. Validated as a suitable method for automatically detecting and analysing the eye and cheek regions from thermal infrared images, the integration of IRT into automated on-farm systems has the potential to be implemented as an automated method of monitoring calf health and welfare.
Respiration rate (RR) is a common measure of cattle health and welfare. Traditionally, measuring RR involves counting flank movements as the animal inhales and exhales with each breath. This method is often considered difficult, labour-intensive and impractical. We validated the use of infrared thermography (IRT) as an alternative method of non-invasively measuring RR in young calves. RR was simultaneously recorded in two ways: (1) by observing flank movements from video recordings; and (2) by observing thermal fluctuations around the nostrils during inhalations and exhalations from infrared recordings. For each method, the time taken to complete five consecutive breaths (a breath being a complete inhalation/exhalation cycle) was recorded and used to calculate RR (breaths/min). From a group of five calves, a total of 12 video recordings and 12 infrared recordings were collected. For each procedure, 47 sets of five consecutive breaths were assessed. The RRs measured from video recordings of flank movements and thermal fluctuations around the nostrils from infrared recordings were highly correlated (R2 = 0.93). Validated as a suitable method for recording RR, future research can now focus on the development of algorithms to automate the use of IRT to support its integration into existing automated systems to remotely monitor calf health and welfare.
Measurements of radiated thermal output are claimed to reflect the metabolic efficiency of mammals. This is important in food-producing animals because a measure of metabolic efficiency may translate to desirable characteristics, such as growth efficiency or residual feed intake, and permit the grouping of animals by metabolic characteristics that can be more precisely managed. This study addresses the question of whether radiated thermal parameters are characteristic of individual animals under normal and metabolically-challenging conditions. Consistency in radiated thermal output was demonstrated over a period of four weeks on condition that a sufficiently representative sample of measurements could be made on individual animals. The study provided evidence that infrared thermography could be used as an automated, rapid, and reliable tool for assessing thermoregulatory processes.
The use of infrared thermography for the identification of lameness in cattle has increased in recent years largely because of its non-invasive properties, ease of automation and continued cost reductions. Thermography can be used to identify and determine thermal abnormalities in animals by characterizing an increase or decrease in the surface temperature of their skin. The variation in superficial thermal patterns resulting from changes in blood flow in particular can be used to detect inflammation or injury associated with conditions such as foot lesions. Thermography has been used not only as a diagnostic tool, but also to evaluate routine farm management. Since 2000, 14 peer reviewed papers which discuss the assessment of thermography to identify and manage lameness in cattle have been published. There was a large difference in thermography performance in these reported studies. However, thermography was demonstrated to have utility for the detection of contralateral temperature difference and maximum foot temperature on areas of interest. Also apparent in these publications was that a controlled environment is an important issue that should be considered before image scanning.
The meat quality characteristics of adult emus transported for 6h before slaughter were determined. Forty-two emus were used in two trials, undertaken under warm and cool weather conditions, respectively. Male emus had significantly higher fat yields than females (12.43kg vs 9.5kg, P=0.002). About 38.1% of the emus had no wounds or bruises, 40.5% had bruises, while 21.4% had small wounds after transport. Meat from injured emus had significantly higher pH45. In warm weather, emus experienced significantly higher loss in body weight than that under cool weather. Drip loss in meat after 24h of storage was higher in emus which had greater live weight loss after transport (r=0.66, P<0.0001), confirming the adverse effects of transport stress on meat quality. Nutrient supplementation did not significantly affect processing yield or meat quality characteristics. This study points to the need for optimizing transport conditions of emus to maintain meat quality.
Many emu farms are located in areas lacking processing facilities that can handle these birds. Thus, long-distance shipping of birds to an abattoir is necessary. Two experiments were conducted, wherein emus were transported in a modified horse trailer for 6 h to an abattoir. Changes in the indices of stress and metabolic homeostasis (hematology, serum biochemistry, enzymes, and body temperature and weight) were used to evaluate the physiological response to transport. The activities of enzymes alanine aminotransferase, aspartate aminotransferase, and creatine kinase increased significantly (P < 0.001) from pretransport to slaughter, indicating muscle cell wall damages. The body temperature of emus was significantly (P < 0.001) increased from 37.0 to 39.6°C after transport in experiment 1 and from 37.2 to 38.9°C in experiment 2. Transport resulted in significant weight loss in both experiments (P < 0.001; 2.1 ± 0.2 kg vs. 0.6 ± 0.2 kg) and posttransport resting at lairage led to slight regaining (P < 0.01) of BW. Oral administration of supplements before and after transport was effective in protecting against muscle damage and faster recovery of BW losses during lairage. The clinical findings were suggestive of the incidence of exertional rhabdomyolysis and thus underlined the need for careful handling and improved transport conditions of emus.
Cook, N. J., Hayne, S. M., Rioja-Lang, F. C., Schaefer, A. L. and Gonyou, H. W. 2013. The collection of multiple saliva samples from pigs and the effect on adrenocortical activity. Can. J. Anim. Sci. 93: 329–333. The validity of collecting multiple saliva samples for the measurement of cortisol was tested in two sampling regimes in two weight classes of grower pigs (50 and 100 kg). The sampling regimes were a high-frequency, short-duration (HFSD) protocol involving collection of multiple samples within approximately 2 min of each other over a period 30 min. The second regime was a low-frequency, long-duration (LFLD) protocol in which samples were collected every 30 min for 3 h. Both sampling regimes were applied to individually housed pigs. The effect of repeated sampling of a focal pig on its cohorts in a group-housed pen was tested using the LFLD regime. There was no evidence of an effect of either of the sampling protocols on salivary cortisol concentrations in individually housed or group-housed pigs. There was some evidence that higher concentrations of salivary cortisol were associated with longer individual sampling durations in the HFSD regime for animals in the 50-kg weight class but not in the 100-kg weight class. The evidence from these experiments indicates that the collection of multiple saliva samples does not affect salivary cortisol concentrations in grower pigs, but that collection of individual samples in as short a time as possible would be prudent to avoid sampling effects in younger animals.
Infrared thermography (IRT) body temperature readings were taken in the ocular region of 258 pigs immediately before slaughter. Levels of lactate were measured in blood taken in the restrainer. Meat quality was assessed in the longissimus dorsi (LD), semimembranosus (SM), and adductor muscles. Ocular IRT (IROT) temperature was correlated with blood lactate levels (r = 0.20; P = 0.001), with pH taken 1 hour postmortem (pH1: r = − 0.18; P = 0.03) and drip loss (r = 0.20; P = 0.02) in the LD muscle, and with pH1 in the SM muscle (r = − 0.20; P = 0.02). Potentially, IROT may be a useful tool to assess the physiological conditions of pigs at slaughter and predict the variation of important meat quality traits. However, the magnitude of the correlations is rather low, so a further development of image capture technique and further studies under more variable preslaughter conditions ensuring a larger pork quality variation are needed.
Eye temperature, measured using infrared thermography (IRT), is a non-invasive tool for evaluating the stress response in cattle, bison and elk to surgical procedures. Infrared thermography has recently revealed that a rapid drop in eye temperature is likely a sympathetically mediated response via vasoconstriction that can be used to detect fear and/or pain related responses in animals to different handling procedures. Infrared thermography may be used in the future as an objective outcome based measure for the evaluation and assessment of animal welfare. Assessing the feather cover of laying hens by IRT, for example, has proven to be a fast, objective and accurate method that more precisely reflects either actual feather cover or areas of bare skin. Infrared thermography has historically been used primarily as a veterinary diagnostic tool in horses and can be expanded for use in other species as varied as elephants. In addition, IRT methodologies have been employed to detect medical conditions as diverse as naval infections in newborn chicks and mastitis in dairy cattle. Recent data has demonstrated that IRT scans of the orbital area in calves allows for the efficacious identification of animals at earlier stages of illness, often several days to over one week before clinical signs were manifest. In concurrent research, individual animal identification using radio frequency identification tags (RFID) and an IRT camera located at a water station have been employed in a remote monitoring system to automatically collect thermal data for the early detection of disease in feedlot cattle.
Two groups of pigs, born and housed under artificial and natural lighting, demonstrated increases in plasma and salivary cortisol levels at the time of weaning (day 24) and following handling and transport, indicating that these husbandry practices are stressful experiences for the animals. Piglets housed under natural light had a mean plasma cortisol response to weaning of 33.7%, compared with 47.9% for pigs in the artificial-lighting condition (P < 0.03). The relative percentage of eosinophils was reduced following weaning in both groups of pigs (P < 0.04). Salivary cortisol levels were significantly increased in response to handling and transport (P < 0.0001). Also, "basal" levels of salivary cortisol were lower in pigs exposed to natural lighting (P < 0.02) but no differences in the magnitude of the response to handling and transport were evident between different lighting conditions. Male pigs raised under artificial lighting had greater fat depth than those raised under natural light (P < 0.03) and a lower lean yield (P < 0.05). The longer photoperiod and full spectrum of natural light probably entrains the circadian rhythm of cortisol to an earlier clock time and are likely to be the major factors in differential cortisol concentrations between lighting conditions. Key words: Lighting, cortisol, saliva, pigs, stress, meat quality
Pigs were fed a commercial conjugated linoleic acid (CLA) mixture, prepared by alkali isomerization of sunflower oil, at 2% of the basal diet, from 61.5 to 106 kg live weight, and were compared to pigs fed the same basal diet with 2% added sunflower oil. The total lipids from liver, heart, inner back fat, and omental fat of pigs fed the CLA diet were analyzed for the incorporation of CLA isomers into all the tissue lipid classes. A total of 10 lipid classes were isolated by three-directional thin-layer chromatography and analyzed by gas chromatography (GC) on long capillary columns and by silver-ion high-performance liquid chromatography (Ag+-HPLC); cholesterol was determined spectrophotometrically. Only trace amounts (<0.1%; by GC) of the 9,11–18∶2 cis/trans and trans, trans isomers were observed in pigs fed the control diet. Ten and twelve CLA isomers in the diet and in pig tissue lipids were sepatated by GC and Ag+-HPLC, respectively. The relative concentration of all the CLA isomers in the different lipid classes ranged from 1 to 6% of the total fatty acids. The four major cis/trans isomers (18.9% 11 cis, 13 trans-18∶2; 26.3% 10 trans, 12 cis-18∶2; 20.4% 9 cis, 11 trans-18∶2; and 16.1% 8 trans, 10 cis-18∶2) constituted 82% of the total CLA isomers in the dietary CLA mixture, and smaller amounts of the corresponding cis,cis (7.4%) and trans,trans (10.1%) isomers were present. The distribution of CLA isomers in inner back fat and in omental fat of the pigs was similar to that found in the diet. The liver triacylglycerols (TAG), free fatty acids (FFA), and cholesteryl esters showed a similar patterns to that found in the diet. The major liver phospholipids showed a marked increase of 9 cis,11 trans-18∶2, ranging from 36 to 54%, compared to that present in the diet. However, liver diphosphatidylglycerol (DPG) showed a high incorporation of the 11 cis,13 trans-18∶2 isomer (43%). All heart lipid classes, except TAG, showed a high content of 11 cis,13 trans-18∶2, which was in marked contrast to results in the liver. The relative proportion of 11 cis,13 trans-18∶2 ranged from 30% in the FFA to 77% in DPG. The second major isomer in all heart lipids was 9 cis,11 trans-18∶2. In both liver and heart lipids the relative proportions of both 10 trans,12 cis-18∶2 and 8 trans,10 cis-18∶2 were significantly lower compared to that found in the diet. The FFA in liver and heart showed the highest content of trans,trans isomers (31 to 36%) among all the lipid classes. The preferential accumulation of the 11 cis,13 trans-18∶2 into cardiac lipids, and in particular the major phospholipid in the inner mitochondrial membrane, DPG, in both heart and liver, appears unique and may be of concern. The levels of 11 cis,13 trans-18∶2 naturally found in foods have not been established.
The transport and handling procedures imposed on beef cattle during the normal course of marketing can be a significant stressor. Factors including time off feed, water deprivation, mixing and the resulting behavioral problems, transport movement, unfamiliar noise, inclement weather, and so forth are often present and collectively result in live weight and carcass losses as well as degraded meat quality. In addition, a growing public concern regarding animal welfare in such situations is evident. Understanding how cattle adapt to and are influenced by these factors is a necessary first step in being able to reduce these stresses and a major research effort globally has been directed toward this end. Studies at the Lacombe Research Center have focused on understanding the role of electrolytes in attenuating transport and handling stress. Apparent in this research has been the consistent observation that transport and handling reduce blood pH, glucose concentration, and interstitial water space (P < .05), and increases in serum chloride. hemoglobin, urine sodium, and urine osmolality (P < .05) are evident. These changes are also accompanied by significant increases in the neutrophile/lymphocyte ratio. The application of oral electrolyte therapy, especially if similar in constituents to interstitial fluid, seems to attenuate these physiological changes. Resulting improvements in both live and carcass weights (less shrink) of up to several percent in treated animals as well as a reduction in meat quality degradation (reduced dark cutting) is evident in such trials. These studies suggest that the use of electrolyte therapy may be an effective means of reducing stress in transported cattle.
1.1.|The effects of acute (12 h) and chronic (10–12 week) cold exposure (3°C) on the distribution of cardiac output and blood flow in adult sheep were measured using radioactive microspheres.2.2.|Increased blood flow was observed in the nonrespiratory skeletal muscles and thyroids of both acute and chronic cold-exposed sheep, whereas, a simultaneous reduction in relative blood flow was observed in reticulorumen, diaphgragm and lower-limb hoof and bone tissue. There as no significant treatment difference in blood flow to the heart, kidney or fat tissues.3.3.|Compared to acute cold, the chronic cold animals demonstrated an increased blood flow to the nonrespiratory skeletal muscles. Based on these findings, it is suggested that skeletal muscle may be of thermoregulatory significance to cold-adapted sheep.
Shipping stress is an economic problem be- cause of its effect on meat quality. Because shipping increases plasma cortisol and pyridoxal 5*-phosphate interacts with steroid hormones, we examined the inter- action between adrenocorticotropic hormone (ACTH) and vitamin B-6 metabolism in pigs. Six crossbred pigs with ear vein catheters received 50 IU of porcine ACTH intravenously at 3-h intervals from 0800 to 2100 h on d 1-3 and 100 IU intramuscularly at 0800, 1400 and 2000 h on d 6 and 7. Controls received saline. ACTH had no effect on pyridoxal 5*-phosphate in adrenal tissue but decreased pyridoxamine 5*-phosphate from 6.1 6 0.7 to 4.7 6 1.0 nmol/g (P < 0.05). Adrenal pyridoxal and pyri- doxamine concentrations were 0.4 6 0.1 nmol/g in con- trols and 1.1 6 0.3 and 1.3 6 0.5 nmol/g, respectively, in ACTH-treated pigs (P < 0.01). Pyridoxal 5*-phosphate phosphatase activity (median (25-75 percentile value)) at pH 7.4 in adrenal tissue was 66.6 (47.8 -75.5) nmol/ (g z min) in the controls and 764 (626 -771) in the ACTH- treated pigs (P < 0.01). There was no significant differ- ence in pyridoxal kinase activity. However, kinase activity in the adrenals was about twice as high as in other tissues. These data suggest an active turnover of vitamin B-6 in adrenal tissue. J. Nutr. 129: 1905-1908, 1999.