Bovine Respiratory Disease Detection Research Articles

PSIII-3 Evaluation of remote detection of heart rate, respiratory rate, and body temperature for improved detection of bovine respiratory disease in high-risk receiving calves

Abstract The objective of this study was to evaluate the effectiveness of the VetGuardian remote monitor to create data-driven detection of bovine respiratory disease (BRD) by identifying vital sign abnormalities for early disease detection. Male calves (n = 20, initial body weight = 213 ± 3 kg) were purchased from regional auction markets and shipped to the University of Arkansas Stocker Receiving Unit. Upon arrival, calves were weighed, branded, received an identification tag, vaccinated, dewormed, and bulls were castrated. On d 1, the remote sensor was used to monitor all calves while restrained in the chute system detecting their body temperatures, and heart and respiratory rates. The remote sensor was placed in 1 of 2 locations for recordings: 1) in front of chute to capture the head, or 2) on the side of chute capturing the torso. Each calf was assigned to a scan location (10 calves/scan location). For all calves, rectal temperatures were also recorded manually, and heart and respiratory rates were determined by thoracic auscultation. Before processing and for the following 28 d, cattle were observed daily for clinical BRD. If presenting symptoms of BRD and if rectal temperature was ≥ 40°C, cattle were deemed morbid and treated with an antibiotic according to a standard preplanned protocol. For any cattle that were examined for BRD the remote sensor was again used for a minimum of 5 min to compare with manual recordings. Statistical analyses were performed using the CORR, MIXED, and MEANS procedures of SAS 9.4 with sex as a random effect and individual calf specified as the subject. There was a positive correlation between manual recordings of rectal temperatures and remote recordings from the head (0.67; P = 0.04) and the side (0.88; P = 0.0008). Remote recordings did not correlate (P ≥ 0.21) with manual recordings for heart rates. However, there was a positive correlation (0.79; P = 0.01) between manual respiratory rates and the side scans, but no relationship (P = 0.16) between manually collected respiratory rates with head scans. LSMeans for temperature data collected manually or by the remote sensor at either location did not differ (P ≥ 0.34). LSMeans for heart rate differed between manual and remote measurements from either location (P ≤ 0.0008). Manual measurements for respiratory rate did not differ (P = 0.26) from remote recordings from the side; however, differed (P < 0.0001) from recordings from the head. In conclusion, the VetGuardian remote sensor varied from manual recordings for heart rates, regardless of sensor location. Scan location had an influence on accuracy of respiratory rate recordings, and body temperature recordings from either location did not differ from manual measurements. Preliminary data should be used for further investigation of this remote sensor.

Early detection of bovine respiratory disease in pre-weaned dairy calves using sensor based feeding, movement, and social behavioural data

Previous research shows that feeding and activity behaviours in combination with machine learning algorithms has the potential to predict the onset of bovine respiratory disease (BRD). This study used 229 novel and previously researched feeding, movement, and social behavioural features with machine learning classification algorithms to predict BRD events in pre-weaned calves. Data for 172 group housed calves were collected using automatic milk feeding machines and ultrawideband location sensors. Health assessments were carried out twice weekly using a modified Wisconsin scoring system and calves were classified as sick if they had a Wisconsin score of five or above and/or a rectal temperature of 39.5 °C or higher. A gradient boosting machine classification algorithm produced moderate to high performance: accuracy (0.773), precision (0.776), sensitivity (0.625), specificity (0.872), and F1-score (0.689). The most important 30 features were 40% feeding, 50% movement, and 10% social behavioural features. Movement behaviours, specifically the distance walked per day, were most important for model prediction, whereas feeding and social features aided in the model’s prediction minimally. These results highlighting the predictive potential in this area but the need for further improvement before behavioural changes can be used to reliably predict the onset of BRD in pre-weaned calves.

A systematic review of the relationship between housing environmental factors and bovine respiratory disease in preweaned calves - Part 2: Temperature, relative humidity and bedding

Bovine respiratory disease (BRD) is a challenge in all housed farming systems that raise calves. Farm to farm variation in BRD prevalence can be partially attributed to variation in host immunity, pathogens and housing environment. Unlike host immunity and BRD pathogens, housing environment has not been well investigated. The objective of this systematic review was to identify the measurable environmental variables associated with BRD in housed preweaned calves. Pubmed, CAB Direct and Scopus databases were searched. To be considered for inclusion publications had to be published in English, before 24 November, 2022 and include at least one measurable/ manipulated environmental variable and a standardized method of BRD detection. In total 12 publications were included in this review. In this second part of the systematic review the environmental variables identified were; temperature (9 publications); relative humidity (8 publications); bedding (5 publications); ventilation (1 publication); air CO2 concentration (1 publication) and air velocity (4 publications). Of the publications that were examined a statistically significant relationship to BRD was identified in 4/9 publications examining temperature, 3/8 examining relative humidity, 2/4 examining air velocity, 2/5 examining bedding, 0/1 examining ventilation rates and 0/1 examining CO2 concentration. From this review it is clear high airspeed at calf level should be avoided as should deep, wet pack bedding. The relationship between BRD prevalence and both high and low temperature requires more investigation to identify temperature thresholds associated with increased risk of BRD as well as the most influential modifiers. An optimal environment for housed calves could not be clearly identified in this review.

Multiplex RT-qPCR Application in Early Detection of Bovine Respiratory Disease in Healthy Calves

Bovine respiratory diseases (BRD) are associated with various predisposing factors, such as physical and physiological stress factors, and bacterial and viral pathogens. These stressors and viruses suppress immune defenses, leading to bacterial growth in the upper respiratory tract and invasion of pathogens into the lower respiratory tract. Therefore, continuous monitoring of the causative pathogens would contribute to the early detection of BRD. Nasal swabs and sera from 63 clinically healthy calves were continuously collected from seven farms in Iwate prefecture from 2019 to 2021. We attempted to monitor dynamics of BRD-associated pathogens by multiplex real-time RT-PCR (RT-qPCR) using their nasal swab samples. In addition, we attempted to monitor fluctuation of antibody titers against each BRD-associated pathogen by virus neutralization test (VNT) using their sera. In contrast, nasal swabs from 89 calves infected with BRD were collected from 28 farms in Iwate prefecture from 2019 to 2021. We attempted to analyze their nasal swab samples by multiplex RT-qPCR aim to detect BRD-associated pathogens that are dominant in this region. As a result, our analyses using samples from clinically healthy calves showed that positive results by multiplex RT-qPCR were closely related to a significant increase of antibody titers by VNT in bovine coronavirus (BCoV), bovine torovirus (BToV), and bovine respiratory syncytial virus (BRSV). In addition, our data exhibited that BCoV, BToV, BRSV, bovine parainfluenza virus 3, and Mycoplasma bovis have been more frequently detected in calves infected with BRD compared to those detected in clinically healthy calves. Moreover, the data presented herein revealed co-infections by combination multiple viral pathogens with bacterial pathogens are closely involved in the onset of BRD. Taken together, our study demonstrates multiplex RT-qPCR which can simultaneously analyze multiple pathogens, including viruses and bacteria, and is useful for the early detection of BRD.

Development and validation of a clinical respiratory disease scoring system for guiding treatment decisions in veal calves using a Bayesian framework.

Active infectious bovine respiratory disease (BRD) is an infection of the airways that needs to be diagnosed correctly so that appropriate treatment can be initiated. The simplest and most practical test to detect active BRD in dairy calves raised for veal is the detection and interpretation of clinical signs by producers or technicians. However, the clinical scoring system currently available for veal calves lacks sensitivity and specificity, contributing to economic losses and high use of antimicrobials. An accurate and reliable batch-level test to detect active BRD is essential to tailor antimicrobial use and reduce economic losses in veal calves. The objective of this study was therefore to develop and validate a new veal calf respiratory clinical scoring system (VcCRS), including reliable clinical signs (cough, ear droop or head tilt) and increased rectal temperature to detect active BRD in batches of veal calves housed individually, and to describe the accuracy of the scoring system for identifying batches of veal calves to treat. During 2017 to 2018, clinical examination, thoracic ultrasonography (TUS) and a haptoglobin concentration (Hap) were prospectively performed on 800 veal calves housed individually in Québec, Canada. Deep nasopharyngeal swabs were performed on 250 veal calves. A Bayesian latent class model accounting for imperfect accuracy of TUS and Hap was used to obtain weights for the clinical signs and develop the VcCRS. The VcCRS was then validated externally in 3 separate data sets. Finally, the applicability of the VcCRS at batch level was determined. We found that calves with 2 of the following findings-cough, unilateral or bilateral ear droop or head tilt, or increased rectal temperature ≥39.7°C-were considered positive and had a 31% chance of having active BRD. Without at least 2 of these 2 findings, a calf had a 100% chance of not having active BRD. At the batch level, we found that a batch with ≥3 positive calves among 10 calves sampled 2 wk after arrival at the fattening unit had a 94% chance of having an active BRD prevalence ≥10%. A batch with <3 positive calves had a 95% chance of not having an active BRD prevalence ≥10%. In this study, we developed a simple individual and batch-level score that is reliable across examiners and performs effectively in the detection of active BRD in veal calves. The implementation of this VcCRS in the veal calf industry would promote the elaboration of a protocol tailoring antimicrobial use.

Technological Tools for the Early Detection of Bovine Respiratory Disease in Farms

Simple SummaryThe inclusion of remote automatic systems that use continuous learning technology are of great interest in precision livestock cattle farming, since the average size of farms is increasing while time for individual observation is decreasing. Bovine respiratory disease is a main concern in both fattening and heifer rearing farms due to its impact on antibiotic use, loss of performance, mortality, and animal welfare. Much scientific literature has been published regarding technologies for continuous learning and monitoring of cattle’s behavior and accurate correlation with health status, including early detection of bovine respiratory disease. This review summarizes the up-to-date technologies for early diagnosis of bovine respiratory disease and discusses their advantages and disadvantages under practical conditions.Classically, the diagnosis of respiratory disease in cattle has been based on observation of clinical signs and the behavior of the animals, but this technique can be subjective, time-consuming and labor intensive. It also requires proper training of staff and lacks sensitivity (Se) and specificity (Sp). Furthermore, respiratory disease is diagnosed too late, when the animal already has severe lesions. A total of 104 papers were included in this review. The use of new advanced technologies that allow early diagnosis of diseases using real-time data analysis may be the future of cattle farms. These technologies allow continuous, remote, and objective assessment of animal behavior and diagnosis of bovine respiratory disease with improved Se and Sp. The most commonly used behavioral variables are eating behavior and physical activity. Diagnosis of bovine respiratory disease may experience a significant change with the help of big data combined with machine learning, and may even integrate metabolomics as disease markers. Advanced technologies should not be a substitute for practitioners, farmers or technicians, but could help achieve a much more accurate and earlier diagnosis of respiratory disease and, therefore, reduce the use of antibiotics, increase animal welfare and sustainability of livestock farms. This review aims to familiarize practitioners and farmers with the advantages and disadvantages of the advanced technological diagnostic tools for bovine respiratory disease and introduce recent clinical applications.

Meta-Analysis of qPCR for Bovine Respiratory Disease Based on MIQE Guidelines.

Qualitative and quantitative PCR-based tests are widely used in both diagnostics and research to assess the prevalence of disease-causing pathogens in veterinary medicine. The efficacy of these tests, usually measured in terms of sensitivity and specificity, is critical in confirming or excluding a clinical diagnosis. We undertook a meta-analysis to assess the inherent value of published PCR diagnostic approaches used to confirm and quantify bacteria and viruses associated with bovine respiratory disease (BRD) in cattle. This review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A thorough search of nine electronic databases (Web of Science, EBSCOhost, Cambridge journals online, ProQuest, PubMed, Sage journals online, ScienceDirect, Wiley online library and MEDLINE) was undertaken to find studies that had reported on the use of PCR and/or qPCR for the detection and/or quantification of BRD associated organisms. All studies meeting the inclusion criteria for reporting quantitative PCR for identification of BRD associated microorganisms were included in the analysis. Studies were then assessed on the applications of the Minimum Information for Publication of Quantitative Real-Time PCR Experiment (MIQE) and PCR primer/probe sequences were extracted and tested for in silico specificity using a high level of stringency. Fourteen full-text articles were included in this study. Of these, 79% of the analysed articles did not report the application of the MIQE guidelines in their study. High stringency in silico testing of 144 previously published PCR primer/probe sequences found many to have questionable specificity. This review identified a high occurrence of primer/probe sequences with a variable in silico specificity such that this may have implications for the accuracy of reporting. Although this analysis was only applied to one specific disease state, identification of animals suspected to be suffering from bovine respiratory disease, there appears to be more broadly a need for veterinary diagnostic studies to adopt international best practice for reporting of quantitative PCR diagnostic data to be both accurate and comparable between studies and methodologies.

Additive Bayesian network analysis of the relationship between bovine respiratory disease and management practices in dairy heifer calves at pre-weaning stage

BackgroundNursery farms that accept nursing and growing pre-weaned heifer calves from private dairy farms must work to prevent bovine respiratory disease (BRD). Knowledge of the BRD-associated risk factors related to calf management and calves’ condition will help to develop appropriate neonatal management practices at original farms and to identify calves at higher risk for BRD at nursery farms. In this study, the relationship between BRD and calf management practices (colostrum feeding, dam parity, serum total protein concentration at introduction (TP), body weight at introduction, introduction season, and daily average growth) was investigated using observational data from pre-weaned dairy calves introduced into a nursery farm in Hokkaido, Japan between 2014 and 2018 (n = 3185). Using additive Bayesian network (ABN) analysis, which is a multivariate statistical modelling approach, the direct and indirect associations between these factors were assessed.ResultsColostrum feeding contributed to an increase in TP (correlation 1.02 [95 % CI, 0.94;1.10]), which was negatively associated with BRD directly (log odds ratio − 0.38 [− 0.46;−0.31]) and indirectly through increasing daily growth (correlation 0.12 [0.09;0.16]). Calves of multiparous dams had higher body weight at introduction (correlation 0.82 [0.74;0.89]), which indirectly reduced BRD risk through the increasing daily growth (correlation 0.17 [0.14;0.21]). Calves introduced during winter had the highest risk for BRD (log odds ratio 0.29 [0.15;0.44]), while those introduced in summer had the lowest risk (log odds ratio − 0.91 [− 1.06;−0.75]). The introduction season was also associated with BRD indirectly through dam parity, body weight at introduction, and daily growth.ConclusionsThe following calf management practices are recommended for preventing BRD in pre-weaned calves at nursery farms: (1) encouraging colostrum feeding to neonatal calves at their original farms; and (2) identifying calves with higher BRD risk, i.e., those without feeding colostrum, born to primiparous cattle, with low body weight at introduction, and/or introduced in winter, and paying intensive attention to the calves for rapid detection of BRD. ABN analysis applied enabled us to understand the complex inter-relationships between BRD incidence and the risk factors, which will help to reduce BRD incidence and to rear healthy calves at nursery farms.

Early prediction of respiratory disease in preweaning dairy calves using feeding and activity behaviors

Bovine respiratory disease (BRD) represents one of the major disease challenges affecting preweaning dairy-bred calves. Previous studies have shown that differences in feeding and activity behaviors exist between healthy and diseased calves affected by BRD. The aim of this study was to develop and assess the accuracy of models designed to predict BRD from feeding and activity behaviors. Feeding and activity behaviors were recorded for 100 male preweaning calves between ~8 to 42 d of age. Calves were group housed with ad libitum access to milk via automatic milk feeders, water, starter diet, and straw. Activity was monitored via a leg-mounted accelerometer. Health status of individual calves was monitored daily using an adapted version of the Wisconsin Scoring System to identify BRD. Three models were created to predict disease: (1) deviation from normal lying time based on moving averages (MA); (2) random forest (RF), a machine learning technique based on feeding and activity variables; and (3) a combination of RF and MA output. For the MA model, lying time was predicted based on behavior over previous days (3- and 7-d MA) and the expected value for the current day (based on calf age; measured using accelerometers). Data were not split into training and test data sets. Occasions when the actual lying time increased >9% of predicted lying time were classified as a deviation from normal and a disease alert was provided. Both feeding and activity behaviors were included within the RF model. Data were split into training (70%) and test (30%) data sets based on disease events. Events were classified as 2 d before, the day(s) of the disease event, and 2 d after the event. Accuracy of models was assessed using sensitivity, specificity, balanced accuracy, and Matthews correlation coefficient (MCC). If a positive disease prediction agreed with an actual disease event within a 3-d rolling window, it was classified as a true positive. Stand-alone models (RF; MA) showed high specificity (0.95; 0.97), moderate sensitivity (0.35; 0.43), balanced accuracy (0.65; 0.64), and MCC (0.25; 0.29). Combining outputs increased accuracy (specificity = 0.95, sensitivity = 0.54, balanced accuracy = 0.75, MCC = 0.36). The work presented is the first to demonstrate the use of modeling data derived from precision livestock farming techniques that monitor feeding and activity behaviors for early detection of BRD in preweaning calves, offering a significant advance in health management of youngstock.

Efficacy of statistical process control procedures to monitor deviations in physical behavior for preclinical detection of bovine respiratory disease in feedlot cattle

Opportunities exist to improve the efficacy of antimicrobial treatment and animal welfare standards through use of remote sensor technologies for early detection of bovine respiratory disease (BRD). A post-hoc analysis using statistical process control (SPC) procedures was performed on continuously-recorded physical activity data collected from BRD-diagnosed and healthy calves from Pillen et al. (2016). We hypothesized that SPC models that monitor physical activity traits (step count, motion index, standing time, lying bouts) would yield higher diagnostic accuracies compared to methods based on visual observation of clinical signs of illness for detecting the onset of BRD. Crossbred steers and bulls (n = 266; initial BW = 180 kg) at high risk for BRD were fitted with leg-attached accelerometers (IceQube, IceRobotics, Ltd.) upon arrival at a commercial feedlot and evaluated for 56 d Overall, calves experienced 48% morbidity, with the average day of first treatment occurring 16 d post-feedlot arrival. Shewhart charts were used to evaluate daily changes in each trait as univariate models and combined traits in principal component analysis (PCA)–constructed multivariate models, relative to the day of BRD diagnosis. Diagnostic test sensitivity and specificity were calculated for each model and compared. The univariate models had relatively low sensitivities (< 40%), with specificities ranging from 23 to 81%, and chart signaling occurred up to 2 d prior to visual diagnosis of BRD. The univariate model for step count had the highest accuracy (52.3%), while lying time had the lowest accuracy (32%). The multivariate models that included all 4 physical activity traits or only lying bout behavior had moderate sensitivities (44 to 57%), but low specificities (< 37%), and chart signaling occurred 2 d prior to visual diagnosis. The relatively low diagnostic test accuracies of the SPC models reported in this study may have been due to substantial within-animal daily variation in the physical activity traits and(or) the limited time for adequate model training prior to the onset of BRD cases. Future research should investigate SPC analysis of multifactorial algorithms using physical activity and feeding behavior traits to improve the accuracy of preclinical detection of BRD.

Early detection of bovine respiratory disease in calves by induced cough

100 Holstein calves aged 7-14 days investigated the effectiveness of various cough provocation methods for bovine respiratory disease early detection. The animals were evaluated according to the clinical scoring system WI, to provoke cough in calves, they performed: 15-minute run, 30-second apnea on exhalation, palpated the trachea in its lower third region and intravenously injected 0.6% hydrogen peroxide solution at 0.9 % sodium chloride solution at a dose of 0.4 ml per kg of body weight to induce H2O2-induced bronchoconstriction. Out of 100 calves, 60 were selected without spontaneous cough and with a WI clinical score of 3 points or less, in which the leukocyte count, differential leukocyte count, neutrophil-to-lymphocyte ratio, nuclear shift index, and pH of exhaled breath condensate and the hydrogen peroxide concentration in exhaled breath. For 2 weeks, these animals were monitored daily for the bovine respiratory disease signs. It was established that 30-second apnea and H2O2-induced bronchoconstriction allow diagnosing bronchitis in calves 6-12 days before its symptom complex (peak) development when other symptoms are still absent and WI clinical score is 3 points or less. However, already at this disease stage, animals exhibit leukocytosis, increased serum content of haptoglobin, decreased pH exhaled breath condensate, and increased the hydrogen peroxide concentration in exhaled breath. The trachea lower third cough on palpation appearance indicates the tracheobronchitis early manifestations presence in calves. Trachea lower third Sequential palpation and 30-second apnoea to provoke coughing in calves allows not only the bovine respiratory disease early detection, but also to differentiate early bronchitis and tracheobronchitis manifestations.

Development and application of molecular diagnostics and proteomics to bovine respiratory disease (BRD)

Advances in molecular and proteomic technologies and methods have enabled new diagnostic tools for bovine respiratory pathogens that are high-throughput, rapid, and extremely sensitive. Classically, diagnostic testing for these pathogens required culture-based approaches that required days to weeks and highly trained technical staff to conduct. However, new advances such as multiplex hydrolysis probe-based real-time PCR technology have enabled enhanced and rapid detection of bovine respiratory disease (BRD) pathogens in a variety of clinical specimens. These tools provide many advantages and have shown superiority over culture for co-infections/co-detections where multiple pathogens are present. Additionally, the integration of matrix-assisted laser desorption ionization time of flight mass spectrometry (MS) into veterinary diagnostic labs has revolutionized the ability to rapidly identify bacterial pathogens associated with BRD. Recent applications of this technology include the ability to type these opportunistic pathogens to the sub-species level (specifically Mannheimia haemolytica) using MS-based biomarkers, to allow for the identification of bacterial genotypes associated with BRD versus genotypes that are more likely to be commensal in nature.

Behavior assessment and applications for BRD diagnosis: beef.

Assessment of behavior is a longstanding strategy to assist the diagnosis of clinical bovine respiratory disease (BRD) in beef cattle. Cattle with systemic inflammation caused by infectious pathogen(s) display predictable behavioral adaptations compared to healthy cohorts. Behavioral alterations in BRD-affected cattle include lethargy, social isolation, and anorexia. However, behavior assessment to support BRD case definition in the production setting is challenging because: (1) other bovine diseases cause behavior alterations similar to BRD; (2) cattle have inherent prey instinct to disguise sickness behavior during human evaluation; (3) labor constraints dictate very brief observation of animal behavior; and (4) traditional behavior assessment is subjective and agreement is often poor. Some of these challenges may be overcome with the use of advanced technologies that allow continuous, remote, and objective behavior assessment of individual cattle. Automated methodologies for behavior assessment include three-axis accelerometers that quantify physical behaviors, systems that document feeding/watering behavior, and triangulation systems that document spatial behavior. Each of these behavior-monitoring approaches generates unique information and may facilitate early detection of BRD compared to traditional methods. Nevertheless, adoption of behavior assessment technologies for BRD diagnosis in beef operations hinges upon improved detection, positive return on investment, and successful integration within existing BRD management practices.

268 Administering an appeasing substance to optimize welfare and performance of receiving cattle

Abstract This experiment evaluated the impacts of bovine appeasing substance (BAS) administration on performance, health, and physiological responses of feedlot cattle during a 45-d receiving period. A total of 342 recently-weaned Angus-influenced steers, originating from 16 cow-calf operations, were obtained from an auction yard on d -1 and road-transported (12 h) to the feedlot. Upon arrival on d 0, body weight (BW) was recorded and steers were ranked by BW and source and assigned to receive BAS (Nutricorp, Araras, SP, Brazil; n = 171) or placebo (diethylene glycol monoethyl ether; CON; n = 171). Treatments (5 mL) were topically applied to the nuchal skin area of each animal. Within treatment, calves were allocated to 1 of 24 drylot pens (12 pens/treatment) and received a free choice total-mixed ration from d 1 to 45. Calves were assessed for bovine respiratory disease (BRD) signs and feed intake was recorded from each pen daily. Steer BW was again recorded on d 1, 7, 17, 31, and 45, whereas blood samples were collected from 5 steers/pen concurrently with each BW assessment. Average daily gain was greater (P = 0.05) in BAS vs. CON calves, although final BW did not differ (P = 0.36) between treatments. No treatment effects were detected for feed intake (P = 0.95), resulting in greater (P = 0.05) feed efficiency in BAS vs. CON steers. No treatment effects were detected (P ≥ 0.37) for plasma concentrations of haptoglobin, whereas plasma cortisol concentrations were greater (P = 0.05) in CON vs. BAS steers on d 7 (treatment × day; P = 0.07). Incidence of BRD was greater (P ≤ 0.05) in BAS vs. CON on d 6 to 10 and d 18 to 21 (treatment × day; P &amp;lt; 0.01), although overall BRD incidence did not differ (P = 0.24) between treatments. The number of antimicrobial treatments required per steer diagnosed with BRD symptoms to recover from sickness was greater (P = 0.04) in CON vs. BAS calves. No treatment differences were detected (P ≥ 0.41) for mortality incidence, or proportion of steers removed from the experiment due to extreme sickness. Results from this experiment indicate BAS administration upon feedlot entry improved average daily gain by enhancing feed efficiency. Administration of BAS facilitated earlier detection of BRD and reduced the need for antimicrobial treatments. Collectively, these results suggest BAS administration as a promising strategy to benefit performance and immunocompetence of feedlot receiving cattle.

Growth performance and hematological changes of weaned beef calves diagnosed with respiratory disease using respiratory scoring and thoracic ultrasonography.

This study investigated 1) the effect of clinical bovine respiratory disease (BRD) and associated lung consolidations on growth performance and hematological profiles of recently weaned beef calves and 2) the relationship between clinical respiratory signs and lung consolidation detected by thoracic ultrasonography (TUS). One hundred and fifty-three weaned beef calves (209 days old [SD: 35.8] and 306 kg [SD: 26.3], at arrival) purchased and transported from auction markets were accommodated indoors in concrete slatted floor pens. Calves were weighed weekly from arrival until day 28 and on day 65 post-arrival. Assessment of BRD and blood sample collection for hematological profiles were performed on scheduled days (at arrival, on days 7, 14, and 28) and on other days upon BRD diagnosis. Animals were assessed for BRD using a total clinical respiratory score (CRS) of five clinical signs (rectal temperature, ear position, cough, nasal secretion, and eye secretion with each ranging from normal [0] to abnormal [3]) and TUS scores (normal [0] to lung consolidation ≥ 1 cm2 [2]). Based on CRS, 35% of calves were CRS+ (CRS ≥ 5) and 65% were CRS- (CRS < 5). Although no lung consolidations (TUS-) were detected at arrival, 34% of calves developed lung consolidation (≥1 cm2) (TUS+) during the first 28 d post-arrival. Only fever (>39.6 °C) and nasal discharge were weakly associated (r = 0.19, P <0.05) with lung consolidation. On the day of BRD detection, neutrophil number and neutrophil:lymphocyte ratio were 58% and 73% greater, respectively, in BRD calves with lung consolidation compared with healthy calves. From day 0 to 65, calf average daily gain (ADG) did not differ (P >0.05) between CRS+ and CRS- calves but was 0.09 kg/d lower (P < 0.05) for TUS+ compared with TUS- calves. Calves classified as BRD (CRS + TUS ≥ 5) with lung consolidation had lower (P < 0.05) ADG from arrival until day 28 than healthy calves and BRD calves without lung consolidation (0.11 ± 0.10 vs. 0.53 ± 0.07 vs. 0.57 ± 0.10 kg/d, respectively); however, no differences in ADG were observed from day 0 to 65. Conventional methods to diagnose BRD failed to detect calves with lung lesions. TUS is a useful tool to detect lung lesions and its implementation in combination with CRS should provide a more accurate and early diagnosis of BRD, which is fundamental to successful treatment, animal welfare, and growth performance.

73 Managing health during the receiving period

Abstract Cattle originating from the southeastern United States and received in stocker and feedlot facilities in the southern Great Plains are at increased risk for bovine respiratory disease (BRD) and other health disorders because the marketing and relocation process may result in stress-induced immunosuppression, increased respiratory virus transmission, and poor nutritional status. Cattle health directly affects growth performance because stress and the inflammatory response to infection results in tissue catabolism and anorexia. Preconditioning practices at the ranch origin, such as vaccination, castration, weaning, and feed bunk and water tank exposure, can significantly improve health outcome during the receiving period; however, this practice is underutilized, resulting in high-risk, commingled calves entering subsequent production sectors. Antimicrobial metaphylaxis is one of the most effective management strategies to control an anticipated outbreak of BRD in newly received calves, yet antimicrobial use in food animals is under intense scrutiny. Antimicrobial alternatives such as direct-fed microbial products may provide health benefits but uncertainty regarding the route and timing of application, effective dose, and product selection will require further research to improve application. Nutritional stress resulting from reduced feed and water intake before, during, and after relocation and potential trace mineral deficiency upon arrival must be considered in a comprehensive health management program. Finally, detection of BRD or other diseases in large groups of cattle is challenging because of the prey instinct to disguise clinical signs of illness. Technology that continuously monitor individual cattle behavior may provide early disease detection with greater sensitivity and specificity than traditional methods but several barriers to adoption exist. This symposium presentation will outline the multitude of factors to consider in managing cattle health during the receiving period and provide research-based evidence that challenge paradigm regarding health management of newly received cattle.

Oral hydration therapy with water and bovine respiratory disease incidence affects rumination behavior, rumen pH, and rumen temperature in high-risk, newly received beef calves.

The study objectives were to determine the effect of oral hydration therapy and bovine respiratory disease (BRD) on rumination behavior, rumen pH, and rumen temperature. A random subset of high-risk, auction-sourced bulls from 3 truckload blocks (initial BW = 188.9 ± 19.1 kg) were fitted with a collar containing a 3-axis accelerometer to quantify rumination time and activity (n = 58) and administered a rumen pH and temperature data logging bolus (n = 33). At arrival, subset calves (n = 2 per pen) were balanced across treatment pens (n = 15 per treatment; n = 10 animals per pen) and randomized to receive 0.57 L water/45.4 kg BW from a modified oral drenching apparatus (H2O) or no water administration (CON). Standard arrival processing procedures were implemented including surgical castration. Modified-live virus respiratory vaccination was delayed until day 28. Technicians assigned a clinical illness score (CIS) daily; calves with CIS ≥ 2 and rectal temperature ≥ 40 °C were considered a BRD case (RCASE) and treated with an antimicrobial. The fixed effect of BRD cases vs. nontreated cohorts (RCON) was determined retrospectively using data from the accelerometer collar (n = 19 and 29) and rumen bolus (n = 12 and 21, for RCASE and RCON, respectively). Daily means and hourly means across days throughout the 56-d observation period were generated. Fixed effects were analyzed using the mixed model procedure with repeated measures. Daily rumen temperature was altered (P = 0.04) such that peak rumen temperature occurred earlier for H2O, whereas CON had increased (P ≤ 0.01) rumen temperature following delayed vaccination on day 28. Calves diagnosed with BRD had a transiently decreased (P = 0.04) active minutes between days 9 and 32, decreased (P < 0.01) active minutes between 0800 and 2000 h, decreased (P < 0.01) rumination time between 2000 and 0400 h, greater (P < 0.01) rumen temperature until delayed vaccination on day 28, and greater (P < 0.01) hourly rumen temperature between 0900 and 0300, and altered (P < 0.01) rumen pH. Earlier peak rumen temperature observed in H2O may indicate physiological modification enabling a more pronounced inflammatory response. Differences in rumination behavior and activity may be useful for early BRD detection.

PSVIII-38 Oral hydration therapy and bovine respiratory disease affects rumination behavior, rumen pH, and rumen temperature in high risk, newly received beef bulls.

The study objectives were to determine the effect of oral hydration therapy and bovine respiratory disease (BRD) on rumination behavior, rumen pH, and rumen temperature. A random subset of high risk, auction-sourced bulls from 3 truckload blocks (initial BW=188.9 ± 19.1 kg) were fitted with a collar containing a 3-axis accelerometer to quantify rumination time and activity index (n=58), and administered a rumen pH and temperature data logging bolus (n=33). At arrival, subset calves (n = 2/pen) were balanced across treatment pens (n=15/treatment; n=10 animals/pen) and randomized to receive 0.57 L water/45.4 kg BW from a modified oral drenching apparatus (H2O) or no water administration (CON). Standard arrival processing procedures were implemented and bulls were surgically castrated. Modified-live virus respiratory vaccination was delayed until day 28. Daily rumen temperature was altered (P=0.04) such that peak rumen temperature occurred earlier for H2O; whereas, CON had increased (P≤0.01) rumen temperature following delayed vaccination on day 28. Technicians assigned a clinical illness score (CIS) daily; calves with CIS ≥2 and rectal temperature ≥40°C were considered a bovine respiratory disease case (BRD) and treated with an antimicrobial. The fixed effect of BRD cases vs. non-treated cohorts (RCON) was determined retrospectively using data from the accelerometer collar (n= 19 vs. 29) and rumen bolus (n= 12 vs. 21). Calves diagnosed with BRD had decreased (P<0.01) rumination time between 2000 and 0400 hours, greater (P<0.01) rumen temperature until delayed vaccination on day 28, greater (P<0.01) hourly rumen temperature between 0900 and 0300, transiently decreased (P=0.04) activity index between day 9 and 32, decreased (P<0.01) activity index between 0800 and 2000, and altered (P<0.01) rumen pH. Earlier peak rumen temperature observed in H2O may indicate physiological modification enabling a more pronounced inflammatory response. Differences in rumination behavior and activity index are potential tools for early BRD detection.

FeverTags: engaging technology in the battle against bovine respiratory disease

Tackling the successful treatment of bovine respiratory disease (BRD) is a challenging problem in clinical practice, with application of drug therapy often occurring quite late down the line of clinical progression, and so resulting in poor treatment outcomes. Temperature detecting technology such as TempVerified FeverTags has been utilised in a set of studies to allow early detection of BRD, and therefore comparison of different treatments and their outcomes in pre-weaning calves. The studies compared antimicrobial and NSAID treatments for BRD, and found that while NSAIDs did allow a potential ~30% reduction in antimicrobial usage, this treatment choice must be accompanied by continuous close monitoring of calves for the occurrence of future cases of BRD.

The effect of lung consolidation, as determined by ultrasonography, on first-lactation milk production in Holstein dairy calves

Bovine respiratory disease (BRD) is a complex disease process and many reports emphasize the negative implications of clinical BRD in dairy calves. Early diagnosis can be difficult because of inconsistent or absent clinical signs; however, the use thoracic ultrasonography has the potential to improve detection of respiratory disease. Earlier detection of BRD may result in actions to improve calf welfare and production. The objective of this prospective cohort study was to determine if lung consolidation (LC) in young dairy calves influenced age at first calving (AFC), first-lactation milk production, and survival to the end of first lactation. A total of 215 female calves from 3 dairy herds in southwestern Ontario were enrolled and assessed weekly during their first 8 wk of life for evidence of LC using thoracic ultrasonography (Ibex Pro, Loveland, CO). Consolidation was measured, using gridlines on the screen of the ultrasound, in the first 10 intercostal spaces on both sides of the thorax. Calves were considered LC positive if ≥3 cm of consolidated lung was present. Multivariable linear regression models were used to identify risk factors associated with AFC and first-lactation 305-d milk production. A survival analysis was conducted to determine differences in survival from enrolment until the end of first lactation between calves with and without consolidation. In the study population, the following calfhood conditions were detected: twins (4%; n = 8), diarrhea in the first 21 d of life (31%; n = 66), rib fractures (7%; n = 14), lung abscesses (3%; n = 6), and at least one diagnosis of LC (57%; n = 123). Overall, 7% (n = 15) of calves died, and 18% (n = 38) of animals were sold before the end of first lactation. The presence of LC, at least once in the first 8 wk of life, did not influence AFC, but did result in a 525 kg (95% confidence interval: -992.81 to -60.25) decrease in first-lactation 305-d milk production. No difference in survival was detected between LC groups. These results indicate that LC during the first 56 d of life has a long-term effect on dairy calves, manifested as reduced milk production during first lactation.