scholarly journals Rapid Communication: Subclinical bovine respiratory disease – loci and pathogens associated with lung lesions in feedlot cattle1

2017 ◽  
Vol 95 (6) ◽  
pp. 2726-2731 ◽  
Author(s):  
◽  
J. N. Kiser ◽  
T. E. Lawrence ◽  
M. Neupane ◽  
C. M. Seabury ◽  
...  
2017 ◽  
Vol 95 (6) ◽  
pp. 2726 ◽  
Author(s):  
J. N. Kiser ◽  
T. E. Lawrence ◽  
M. Neupane ◽  
C. M. Seabury ◽  
J. F. Taylor ◽  
...  

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
C. Blakebrough-Hall ◽  
A. Dona ◽  
M. J. D’occhio ◽  
J. McMeniman ◽  
L. A González

AbstractCurrent diagnosis methods for Bovine Respiratory Disease (BRD) in feedlots have a low diagnostic accuracy. The current study aimed to search for blood biomarkers of BRD using 1H NMR metabolomics and determine their accuracy in diagnosing BRD. Animals with visual signs of BRD (n = 149) and visually healthy (non-BRD; n = 148) were sampled for blood metabolomics analysis. Lung lesions indicative of BRD were scored at slaughter. Non-targeted 1H NMR metabolomics was used to develop predictive algorithms for disease classification using classification and regression trees. In the absence of a gold standard for BRD diagnosis, six reference diagnosis methods were used to define an animal as BRD or non-BRD. Sensitivity (Se) and specificity (Sp) were used to estimate diagnostic accuracy (Acc). Blood metabolomics demonstrated a high accuracy at diagnosing BRD when using visual signs of BRD (Acc = 0.85), however was less accurate at diagnosing BRD using rectal temperature (Acc = 0.65), lung auscultation score (Acc = 0.61) and lung lesions at slaughter as reference diagnosis methods (Acc = 0.71). Phenylalanine, lactate, hydroxybutyrate, tyrosine, citrate and leucine were identified as metabolites of importance in classifying animals as BRD or non-BRD. The blood metabolome classified BRD and non-BRD animals with high accuracy and shows potential for use as a BRD diagnosis tool.


2020 ◽  
Vol 98 (2) ◽  
Author(s):  
Claudia Blakebrough-Hall ◽  
Joe P McMeniman ◽  
Luciano A González

Abstract Bovine respiratory disease (BRD) causes significant economic losses to the feedlot industry due to decreased production and increased costs associated with treatment. This study aimed to assess the impacts of BRD on performance, carcass traits, and economic outcomes defined using four BRD diagnosis methods: number of BRD treatments an animal received, pleural lesions at slaughter, lung lesions at slaughter, and clinical BRD status defined using both treatment records and lung and pleural lesions. Crossbred steers (n = 898), with an initial body weight of 432 kg (± SD 51), were followed from feedlot entry to slaughter. Veterinary treatment records were collected and lungs scored at slaughter for lesions indicative of BRD. There was an 18% morbidity rate and a 2.1% BRD mortality rate, with an average net loss of AUD$1,647.53 per BRD mortality. Animals treated ≥3 times for BRD had 39.6 kg lighter carcasses at slaughter and returned an average of AUD$384.97 less compared to animals never treated for BRD (P < 0.001). Animals with severe lung lesions at slaughter grew 0.3 kg/d less, had 14.3 kg lighter carcasses at slaughter, and returned AUD$91.50 less than animals with no lung lesions (P < 0.001). Animals with subclinical and clinical BRD had 16.0 kg and 24.1 kg lighter carcasses, respectively, and returned AUD$67.10 and AUD$213.90 less at slaughter, respectively, compared to healthy animals that were never treated with no lesions (P < 0.001). The severity of BRD based on the number of treatments an animal received and the severity of lung and pleural lesions reduced animal performance, carcass weight and quality, and economic returns. Subclinical BRD reduced animal performance and economic returns compared to healthy animals; however, subclinical animals still had greater performance than animals with clinical BRD. This information can be used to plan for strategic investments aimed at reducing the impacts of BRD in feedlot cattle such as improved detection methods for subclinical animals with lesions at slaughter and BRD treatment protocols.


2019 ◽  
Vol 35 (3) ◽  
pp. 209-217
Author(s):  
Vladimir Kurcubic ◽  
Radojica Djokovic ◽  
Zoran Ilic ◽  
Nikola Vaskovic ◽  
Milos Petrovic

Bovine respiratory disease complex (BRDC) is the biggest health problem of the cattle industry globally due to the high prevalence and economic consequences which arise due to numerous reasons. Huge economic losses are most often attributed to high morbidity and mortality, reduction of Average Daily Gain (ADG) and food utilization, weight loss, lower quality of carcasses and comprehensive measures of prophylaxis and therapy. BRDC commonly observed throughout the feedlot phase due to the stress factors. Predisposing factors divided didactic on environmental (inclement weather conditions, inadequate humidity and dust), host factors (age, sex, race, genetics, immune status) and stressful management practices (transportation, nutritional stress, metabolic disease, high density of animals, handling, castration, dehorning). In complex etiopathogenesis, in addition to the aforementioned predisposing factors, numerous viral and bacterial agents are involved. Gross lung lesions are most commonly observed in cattle slaughter or autopsies (visible to the naked eye) occur as a result of pneumonia. It is the result of an infection by the bovine respiratory syncytial virus (BRSV), parainfluenza virus type 3 (PI3V), bovine herpes virus type 1 (BoHV1) and bovine viral diarrhea virus (BVDV) alone or in combination with one another, as well the common bacterial pathogens Mannheimia haemolytica, Pasteurella multocida, Histophilus somni and Micrococcus spp. Numerous studies have pointed to the detrimental effects on performance and carcass characteristics.


2021 ◽  
Vol 74 (1) ◽  
Author(s):  
Inmaculada Cuevas-Gómez ◽  
Mark McGee ◽  
José María Sánchez ◽  
Edward O’Riordan ◽  
Nicky Byrne ◽  
...  

Abstract Background Bovine respiratory disease (BRD) is the main cause of mortality among 1-to-5 month old calves in Ireland, accounting for approximately one-third of deaths. Despite widespread use of clinical respiratory signs for diagnosing BRD, lung lesions are detected, using thoracic ultrasonography (TUS) or following post-mortem, in calves showing no clinical signs. This highlights the limitation of clinical respiratory signs as a method of detecting sub-clinical BRD. Using 53 purchased artificially-reared male dairy calves, the objectives of this study were to: (i) characterise the BRD incidence detected by clinical respiratory signs and/or TUS, (ii) investigate the association between clinical respiratory signs and lung lesions detected by TUS, and (iii) assess the effect of BRD on pre-weaning growth. Results Clinical BRD (based on Wisconsin clinical respiratory score and/or rectal temperature > 39.6 ºC) was detected in 43 % and sonographic changes (lung lesions) were detected in 64 % of calves from purchase (23 (SD; 6.2) days of age) until weaning, 53 days post-arrival. Calves with clinical BRD were treated. Sixty-one per cent calves affected with clinical BRD had lung lesions 10.5 days (median) before detection of clinical signs. Moderate correlations (rsp 0.70; P < 0.05) were found between cough and severe lung lesions on arrival day, and between rectal temperature > 39.6 ºC and lung lesions ≥ 2 cm2 on day 7 (rsp 0.40; P < 0.05) post-arrival. Mean average daily live weight gain (ADG) of calves from purchase to weaning was 0.75 (SD; 0.10) kg; calves with or without clinical BRD did not differ in ADG (P > 0.05), whereas ADG of those with severe lung lesions (lung lobe completely consolidated or pulmonary emphysema) was 0.12 kg/d less (P < 0.05) than calves without lung lesions. Conclusions Thoracic ultrasonography detected lung consolidation in calves that did not show signs of respiratory disease. The presence of severe lung lesions was associated with reduced pre-weaning growth. These findings emphasise the importance of using TUS in addition to clinical respiratory scoring of calves for an early and accurate detection of clinical and sub-clinical BRD.


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