Factors associated with Bovine Respiratory Disease case fatality in feedlot cattle

2021 ◽  
Author(s):  
C Blakebrough-Hall ◽  
P Hick ◽  
T J Mahony ◽  
L A González
Keyword(s):  
Respiratory Disease ◽  
Nasal Swab ◽  
Animal Health ◽  
Bovine Respiratory Disease ◽  
Case Fatality ◽  
Mixed Effects ◽  
Feedlot Cattle ◽  
Blood Metabolites ◽  
Factors Associated ◽  
Production Factors

Abstract Bovine Respiratory Disease (BRD) is the primary cause of morbidity and mortality in cattle feedlots. There is a need to understand what animal health and production factors are associated with increased mortality risk due to BRD. The aim of the present study was to explore factors associated with BRD case fatality in feedlot cattle. Four pens totalling 898 steers were monitored daily for visual signs of BRD such as difficult breathing and coughing, and animals exhibiting signs of BRD were taken to the hospital shed for further examination and clinical measures. Blood samples were obtained at feedlot entry and at time of first BRD pull from animals diagnosed with BRD (n=121) and those that died due to BRD confirmed by post-mortem examination (n=16; 13.2% case fatality rate). Mixed-effects linear regression models were used to estimate differences in animal health and production factors and the relative concentrations of 34 identified blood metabolites between animals that survived versus those that died. Generalised linear mixed-effects models were used to obtain the odds of being seronegative (at both feedlot entry and first BRD pull) to five BRD viruses and having a positive nasal swab result at the time of first pull in died and survived animals. Animals that died from BRD had lower average daily gain (ADG), reduced weight at first BRD pull, higher visual BRD scores and received more treatments for BRD compared to animals that survived BRD (P < 0.05). The odds of being seronegative for bovine viral diarrhea virus 1 (BVDV-1) was 5.66 times higher for animals that died compared to those that survived (P = 0.013). The odds of having a positive bovine coronavirus nasal swab result were 13.73 times higher in animals that died versus those that survived (P = 0.007). Animals that died from BRD had higher blood concentrations of α glucose chain, β-hydroxybutyrate, leucine, phenylalanine and pyruvate compared to those that survived (P < 0.05). Animals that died from BRD had lower concentrations of acetate, citrate and glycine compared to animals that survived (P < 0.05). The results of the current study suggest that ADG to first BRD pull, weight at first BRD pull, visual BRD score, the number of BRD treatments, seronegativity to BVDV-1, virus positive to BCoV nasal swab, and that certain blood metabolites are associated with BRD case fatality risk. The ability of these measures to predict the risk of death due to BRD needs further research.

scholarly journals Development of Bacterial Therapeutics against the Bovine Respiratory Pathogen Mannheimia haemolytica

2019 ◽  
Vol 85 (21) ◽  
Author(s):  
Samat Amat ◽  
Edouard Timsit ◽  
Danica Baines ◽  
Jay Yanke ◽  
Trevor W. Alexander
Keyword(s):  
Respiratory Disease ◽  
Animal Health ◽  
Bovine Respiratory Disease ◽  
Feedlot Cattle ◽  
Mitigation Strategies ◽  
Commensal Bacteria ◽  
Mannheimia Haemolytica ◽  
Respiratory Pathogen ◽  
Content Type

ABSTRACT Bovine respiratory disease (BRD) is a major cause of morbidity and mortality in beef cattle. Recent evidence suggests that commensal bacteria of the bovine nasopharynx have an important role in maintaining respiratory health by providing colonization resistance against pathogens. The objective of this study was to screen and select bacterial therapeutic candidates from the nasopharynxes of feedlot cattle to mitigate the BRD pathogen Mannheimia haemolytica. In a stepwise approach, bacteria (n = 300) isolated from the nasopharynxes of 100 healthy feedlot cattle were identified and initially screened (n = 178 isolates from 12 different genera) for growth inhibition of M. haemolytica. Subsequently, selected isolates were evaluated for the ability to adhere to bovine turbinate (BT) cells (n = 47), compete against M. haemolytica for BT cell adherence (n = 15), and modulate gene expression in BT cells (n = 10). Lactobacillus strains had the strongest inhibition of M. haemolytica, with 88% of the isolates (n =33) having inhibition zones ranging from 17 to 23 mm. Adherence to BT cells ranged from 3.4 to 8.0 log10 CFU per 105 BT cells. All the isolates tested in competition assays reduced M. haemolytica adherence to BT cells (32% to 78%). Among 84 bovine genes evaluated, selected isolates upregulated expression of interleukin 8 (IL-8) and IL-6 (P < 0.05). After ranking isolates for greatest inhibition, adhesion, competition, and immunomodulation properties, 6 Lactobacillus strains from 4 different species were selected as the best candidates for further development as intranasal bacterial therapeutics to mitigate M. haemolytica infection in feedlot cattle. IMPORTANCE Bovine respiratory disease (BRD) is a significant animal health issue impacting the beef industry. Current BRD prevention strategies rely mainly on metaphylactic use of antimicrobials when cattle enter feedlots. However, a recent increase in BRD-associated bacterial pathogens that are resistant to metaphylactic antimicrobials highlights a pressing need for the development of novel mitigation strategies. Based upon previous research showing the importance of respiratory commensal bacteria in protecting against bronchopneumonia, this study aimed to develop bacterial therapeutics that could be used to mitigate the BRD pathogen Mannheimia haemolytica. Bacteria isolated from the respiratory tracts of healthy cattle were characterized for their inhibitory, adhesive, and immunomodulatory properties. In total, 6 strains were identified as having the best properties for use as intranasal therapeutics to inhibit M. haemolytica. If successful in vivo, these strains offer an alternative to metaphylactic antimicrobial use in feedlot cattle for mitigating BRD.

scholarly journals Predicting bovine respiratory disease outcome in feedlot cattle using latent class analysis

2020 ◽  
Vol 98 (12) ◽  
Author(s):  
Claudia Blakebrough-Hall ◽  
Paul Hick ◽  
Luciano A González
Keyword(s):  
Latent Class Analysis ◽  
Respiratory Disease ◽  
Rectal Temperature ◽  
Nasal Swab ◽  
Latent Class ◽  
Bovine Respiratory Disease ◽  
Feedlot Cattle ◽  
Disease Outcome ◽  
Computer Assisted ◽  
Class Analysis

Abstract Bovine respiratory disease (BRD) is the most significant disease affecting feedlot cattle. Indicators of BRD often used in feedlots such as visual signs, rectal temperature, computer-assisted lung auscultation (CALA) score, the number of BRD treatments, presence of viral pathogens, viral seroconversion, and lung damage at slaughter vary in their ability to predict an animal’s BRD outcome, and no studies have been published determining how a combination of these BRD indicators may define the number of BRD disease outcome groups. The objectives of the current study were (1) to identify BRD outcome groups using BRD indicators collected during the feeding phase and at slaughter through latent class analysis (LCA) and (2) to determine the importance of these BRD indicators to predict disease outcome. Animals with BRD (n = 127) were identified by visual signs and removed from production pens for further examination. Control animals displaying no visual signs of BRD (n = 143) were also removed and examined. Blood, nasal swab samples, and clinical measurements were collected. Lung and pleural lesions indicative of BRD were scored at slaughter. LCA was applied to identify possible outcome groups. Three latent classes were identified in the best model fit, categorized as non-BRD, mild BRD, and severe BRD. Animals in the mild BRD group had a higher probability of having visual signs of BRD compared with non-BRD and severe BRD animals. Animals in the severe BRD group were more likely to require more than 1 treatment for BRD and have ≥40 °C rectal temperature, ≥10% total lung consolidation, and severe pleural lesions at slaughter. Animals in the severe BRD group were also more likely to be naïve at feedlot entry and the first BRD pull for Bovine Viral Diarrhoea Virus, Bovine Parainfluenza 3 Virus, and Bovine Adenovirus and have a positive nasal swab result for Bovine Herpesvirus Type 1 and Bovine Coronavirus. Animals with severe BRD had 0.9 and 0.6 kg/d lower overall ADG (average daily gain) compared with non-BRD animals and mild BRD animals (P &lt; 0.001). These results demonstrate that there are important indicators of BRD severity. Using this information to predict an animal’s BRD outcome would greatly enhance treatment efficacy and aid in better management of animals at risk of suffering from severe BRD.

scholarly journals Management factors associated with bovine respiratory disease in preweaned calves on California dairies: The BRD 100 study

2019 ◽  
Vol 102 (8) ◽  
pp. 7288-7305 ◽  
Author(s):  
G.U. Maier ◽  
W.J. Love ◽  
B.M. Karle ◽  
S.A. Dubrovsky ◽  
D.R. Williams ◽  
...  
Keyword(s):  
Respiratory Disease ◽  
Bovine Respiratory Disease ◽  
Factors Associated ◽  
Management Factors

scholarly journals A systematic review and network meta-analysis of injectable antibiotic options for the control of bovine respiratory disease in the first 45 days post arrival at the feedlot

2019 ◽  
Vol 20 (2) ◽  
pp. 163-181
Author(s):  
A. M. O'Connor ◽  
D. Hu ◽  
S. C. Totton ◽  
N. Scott ◽  
C. B. Winder ◽  
...  
Keyword(s):  
Systematic Review ◽  
Beef Cattle ◽  
Respiratory Disease ◽  
Citation Index ◽  
Meta Analysis ◽  
Bovine Respiratory Disease ◽  
The United States ◽  
Feedlot Cattle ◽  
Freedom Of Information ◽  
Biological Index

AbstractWe conducted a systematic review and network meta-analysis to determine the comparative efficacy of antibiotics used to control bovine respiratory disease (BRD) in beef cattle on feedlots. The information sources for the review were: MEDLINE®, MEDLINE In-Process and MEDLINE® Daily, AGRICOLA, Epub Ahead of Print, Cambridge Agricultural and Biological Index, Science Citation Index, Conference Proceedings Citation Index – Science, the Proceedings of the American Association of Bovine Practitioners, World Buiatrics Conference, and the United States Food and Drug Administration Freedom of Information New Animal Drug Applications summaries. The eligible population was weaned beef cattle raised in intensive systems. The interventions of interest were injectable antibiotics used at the time the cattle arrived at the feedlot. The outcome of interest was the diagnosis of BRD within 45 days of arrival at the feedlot. The network meta-analysis included data from 46 studies and 167 study arms identified in the review. The results suggest that macrolides are the most effective antibiotics for the reduction of BRD incidence. Injectable oxytetracycline effectively controlled BRD compared with no antibiotics; however, it was less effective than macrolide treatment. Because oxytetracycline is already commonly used to prevent, control, and treat BRD in groups of feedlot cattle, the use of injectable oxytetracycline for BRD control might have advantages from an antibiotic stewardship perspective.

Sign in / Sign up

Export Citation Format

Share Document