Determination of Behavioral Changes Associated with Bovine Respiratory Disease in Australian Feedlots.

Accurately identifying bovine respiratory disease is challenging in feedlots, and previous studies suggest behavioral monitoring is important. The study objective was to describe individual differences in physical activity (distance traveled), feeding/watering patterns (proximity to feed and water), and social behavior (average cattle within 3 m) when associated with health status in commercially raised beef cattle during the first 28 days on feed. Data from a previous Australian feedlot study monitoring cattle behavior and associated health outcomes were analyzed.

Environmental performance of commercial beef production systems utilizing conventional productivity-enhancing technologies.

The objective of this study was to evaluate the effects of using conventional productivity-enhancing technologies (PETs) with or without other natural PETs on the growth performance, carcass traits, and environmental impacts of feedlot cattle. A total of 768 cross-bred yearling steers (499 ± 28.6 kg;  = 384) and heifers (390 ± 34.

Evaluating the effects of antimicrobial drug use on the ecology of antimicrobial resistance and microbial community structure in beef feedlot cattle.

Introduction: Use of antimicrobial drugs (AMDs) in food producing animals has received increasing scrutiny because of concerns about antimicrobial resistance (AMR) that might affect consumers. Previously, investigations regarding AMR have focused largely on phenotypes of selected pathogens and indicator bacteria, such as or . However, genes conferring AMR are known to be distributed and shared throughout microbial communities.

Genomic Characterization of From Beef Cattle Feedlots and Associated Environmental Continuum.

Enterococci are commensal bacteria of the gastrointestinal tract of humans, animals, and insects. They are also found in soil, water, and plant ecosystems. The presence of enterococci in human, animal, and environmental settings makes these bacteria ideal candidates to study antimicrobial resistance in the One-Health continuum.

Prevalence and Risk Factors Associated With Antimicrobial Resistance in Bacteria Related to Bovine Respiratory Disease-A Broad Cross-Sectional Study of Beef Cattle at Entry Into Canadian Feedlots.

A broad, cross-sectional study of beef cattle at entry into Canadian feedlots investigated the prevalence and epidemiology of antimicrobial resistance (AMR) in , and , bacterial members of the bovine respiratory disease (BRD) complex. Upon feedlot arrival and before antimicrobials were administered at the feedlot, deep nasopharyngeal swabs were collected from 2,824 feedlot cattle in southern and central Alberta, Canada. Data on the date of feedlot arrival, cattle type (beef, dairy), sex (heifer, bull, steer), weight (kg), age class (calf, yearling), source (ranch direct, auction barn, backgrounding operations), risk of developing BRD (high, low), and weather conditions at arrival (temperature, precipitation, and estimated wind speed) were obtained.

Association between computer-aided lung auscultation and treatment failure risk in calves treated for respiratory disease.

The use of computer-aided lung auscultation (CALA, Whisper Veterinary Stethoscope; Merck Animal Health, Madison, New Jersey, USA) is a relatively new approach to assist in confirming the diagnosis of bovine respiratory disease (BRD). For this prospective cohort study at 1 feedlot in the United States, a CALA score was generated for 2726 feeder cattle (calf-fed Holsteins and mixed-breed beef animals) at the time of the first BRD diagnosis and treatment. All cattle were treated according to the same BRD protocol prescribed for that facility and the protocol was not influenced by the CALA score.

Bovine respiratory disease treatment failure: definition and impact.

Bovine respiratory disease (BRD) treatment failure occurs when animals receiving a treatment regimen for BRD fail to directly return to health, resulting in chronic illness and a requirement for repeated treatments, sale for salvage slaughter, euthanasia or death. BRD treatment failure has both direct and indirect impacts. Direct impacts include costs to manage chronically ill animals, including those associated with BRD relapse treatment; reduced returns from animals sent for salvage slaughter, loss of the initial investment to purchase the animal and feed and other accumulated expenses to death, and costs associated with carcass disposal.

Corrigendum: Multidrug Resistance in Associated With Bovine Respiratory Disease Mortalities in North America From 2011 to 2016.

[This corrects the article DOI: 10.3389/fmicb.2020.

Use of 3-nitrooxypropanol in a commercial feedlot to decrease enteric methane emissions from cattle fed a corn-based finishing diet.

The present study evaluated enteric CH4 production, dry matter (DM) intake (DMI), and rumen fermentation in feedlot cattle supplemented with increasing concentrations of 3-nitrooxypropanol (3-NOP). A total of 100 crossbred steers (body weight, 421 ± 11 kg) was randomly assigned to one of four treatments (n = 25/treatment): control (no 3-NOP) or low (100 mg/kg DM), medium (125 mg/kg DM), and high (150 mg/kg DM) doses of 3-NOP. The study was comprised of 28 d of adaptation followed by three 28-d periods, with CH4 measured for 7 d per period and cattle remaining on their respective diets throughout the 112-d study.

Feedlot Cattle Antimicrobial Use Surveillance Network: A Canadian Journey.

Antimicrobial drugs are important tools for maintaining human and animal health. Globally, antimicrobial use (AMU) in food-producing animals is under increasing scrutiny due to its potential to promote antimicrobial resistance (AMR). Historically, comprehensive Canadian data related to the types of antimicrobial drugs used, extent of use, common indicators of use and the demographics of the cattle populations receiving antimicrobial drugs have been limited, in part due to segmentation in the cattle industry and fragmentation of the drug distribution system.

Multidrug Resistance in Associated With Bovine Respiratory Disease Mortalities in North America From 2011 to 2016.

Multidrug-resistant (MDR; resistance to ≥3 antimicrobial classes) members of the family may compromise the efficacy of therapies used to prevent and treat bovine respiratory disease (BRD) in feedlot cattle. This study examined the prevalence of multidrug resistance in strains of and collected from BRD cattle mortalities in North America. Isolates of ( = 147) and ( = 70) spanning 69 Alberta feedlots from 2011 to 2016 and two United States feedlots from 2011 to 2012 were examined for antimicrobial resistance (AMR) in association with integrative and conjugative elements (ICEs).

Author Correction: Surveillance of Enterococcus spp. reveals distinct species and antimicrobial resistance diversity across a One-Health continuum.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

A One Health Comparative Assessment of Antimicrobial Resistance in Generic and Extended-Spectrum Cephalosporin-Resistant from Beef Production, Sewage and Clinical Settings.

This study aimed to compare antimicrobial resistance (AMR) in extended-spectrum cephalosporin-resistant and generic from a One Health continuum of the beef production system in Alberta, Canada. A total of 705 extended-spectrum cephalosporin-resistant (ESC) were obtained from: cattle feces (CFeces, = 382), catch basins (CBasins, = 137), surrounding streams (SStreams, = 59), beef processing plants (BProcessing, = 4), municipal sewage (MSewage; = 98) and human clinical specimens (CHumans, = 25). Generic isolates (663) included: CFeces ( = 142), CBasins ( = 185), SStreams ( = 81), BProcessing ( = 159) and MSewage ( = 96).

Bovine Respiratory Disease Treatment Failure: Impact and Potential Causes.

Bovine respiratory disease (BRD) is often attributed to complex interactions between the host, pathogen, and the environment. Likewise, many BRD treatment failures result from interactions between the host, pathogen, environment, drug, and drug administrator. Investigating and addressing the underlying causes of BRD treatment failures can improve clinical outcomes and animal welfare of future cases, improve morale of employees, reduce direct costs of dealing with BRD treatment failures, refine antimicrobial prescribing practices, and advance antimicrobial stewardship.

Whole Genome Sequencing Differentiates Presumptive Extended Spectrum Beta-Lactamase Producing along Segments of the One Health Continuum.

Antimicrobial resistance (AMR) has important implications for the continued use of antibiotics to control infectious diseases in both beef cattle and humans. AMR along the One Health continuum of the beef production system is largely unknown. Here, whole genomes of presumptive extended-spectrum β-lactamase (ESBL-EC) from cattle feces ( = 40), feedlot catch basins ( = 42), surrounding streams ( = 21), a beef processing plant ( = 4), municipal sewage ( = 30), and clinical patients ( = 25) are described.

Investigation of a Reduction in Tylosin on the Prevalence of Liver Abscesses and Antimicrobial Resistance in Enterococci in Feedlot Cattle.

Recent concerns over linkages between antimicrobial resistance in human pathogens and antimicrobial use in livestock have prompted researchers to investigate management strategies that reduce the current reliance on in-feed tylosin to control liver abscesses in feedlot cattle. A total of 7,576 crossbred yearlings were allocated to the study (~253 animals/pen, 10 replicate pens per treatment) and individually randomized to one of three treatments. Tylosin phosphate (11 ppm) was included in-feed (1) for the first 125 days on feed (DOF) (), (2) for DOF 41 to 161 (), or (3) for the entire feeding period (; day 0-161).

Surveillance of Enterococcus spp. reveals distinct species and antimicrobial resistance diversity across a One-Health continuum.

For a One-Health investigation of antimicrobial resistance (AMR) in Enterococcus spp., isolates from humans and beef cattle along with abattoirs, manured fields, natural streams, and wastewater from both urban and cattle feedlot sources were collected over two years. Species identification of Enterococcus revealed distinct associations across the continuum.

Antimicrobial Use on 36 Beef Feedlots in Western Canada: 2008-2012.

The accurate quantification of antimicrobial use (AMU) in production animals is critical for monitoring trends in exposure to antimicrobial drugs (AMD) over time and examining potential associations with antimicrobial resistance in bacteria. In this study, a census sample of cattle was used to quantify individually-dosed and in-feed AMU as both numbers of animal daily doses (nADD) and total grams of AMD (gAMD) used in cattle placed in 36 western Canadian feedlots between 1-November, 2008 and 31-October, 2012; representing about 21.5% of fed cattle in Canada during that time period.

Calculation of Antimicrobial Use Indicators in Beef Feedlots-Effects of Choice of Metric and Standardized Values.

The potential for antimicrobial use (AMU) to lead to the development of antimicrobial resistant bacteria is an increasingly important priority in human and veterinary medicine. Accurate AMU quantification is essential to assessing the risk of antimicrobial resistance due to AMU. The quantification of AMU in production animals can be difficult, and feedlot beef cattle present a number of unique challenges.

Characterization of the Microbial Resistome in Conventional and "Raised Without Antibiotics" Beef and Dairy Production Systems.

Metagenomic investigations have the potential to provide unprecedented insights into microbial ecologies, such as those relating to antimicrobial resistance (AMR). We characterized the microbial resistome in livestock operations raising cattle conventionally (CONV) or without antibiotic exposures (RWA) using shotgun metagenomics. Samples of feces, wastewater from catchment basins, and soil where wastewater was applied were collected from CONV and RWA feedlot and dairy farms.

Presence and Diversity of Extended-Spectrum Cephalosporin Resistance Among from Urban Wastewater and Feedlot Cattle in Alberta, Canada.

A recent preliminary study from our group found that extended-spectrum cephalosporin-resistance determinants can be detected in the majority of composite fecal samples collected from Alberta feedlot cattle. Most notably, genes were detected in 46.5% of samples.

Plasmid Distribution among from Livestock and Associated Wastewater: Unraveling Factors That Shape the Presence of Genes Conferring Third-Generation Cephalosporin Resistance.

A key concern with agricultural wastewater storage ponds is that they may provide an environment conducive for horizontal exchange of antibiotic resistance genes (ARGs), thereby facilitating the emergence of antibiotic resistant pathogens. Central to this exchange are mobile genetic elements like plasmids; yet, the factors shaping their presence in agricultural environments remain poorly understood. Here, using as a model bacterium, we examined genetic backgrounds and plasmid profiles of generic fecal and wastewater isolates and those possessing and genes (which confer resistance to third-generation cephalosporins) to delineate factors shaping the environmental persistence of plasmid-associated ARGs in beef cattle feedlots.

Comparative diversity of microbiomes and Resistomes in beef feedlots, downstream environments and urban sewage influent.

Background: Comparative knowledge of microbiomes and resistomes across environmental interfaces between animal production systems and urban settings is lacking. In this study, we executed a comparative analysis of the microbiota and resistomes of metagenomes from cattle feces, catch basin water, manured agricultural soil and urban sewage.

Results: Metagenomic DNA from composite fecal samples (FC; n = 12) collected from penned cattle at four feedlots in Alberta, Canada, along with water from adjacent catchment basins (CB; n = 13), soil (n = 4) from fields in the vicinity of one of the feedlots and urban sewage influent (SI; n = 6) from two municipalities were subjected to Illumina HiSeq2000 sequencing.

Association of lung lesions measured by thoracic ultrasonography at first diagnosis of bronchopneumonia with relapse rate and growth performance in feedlot cattle.

Background: Severity of lung lesions quantified by thoracic ultrasonography (TUS) at time of bronchopneumonia (BP) diagnosis predicted death among steers not treated for this condition. Further research is needed to confirm that lung lesions detected by TUS can be associated with negative outcomes in cattle with BP that subsequently were treated.

Objective: To quantify the effects on relapse rate and average daily gain (ADG) of lung lesions detected by TUS at first BP diagnosis in feedlot cattle.