Population-level effects of risk factors for bovine respiratory disease in Australian feedlot cattle

Abstract

Please cite this article as: Hay, K.E., Morton, J.M., Clements, A.C.A., Mahony, T.J., Barnes, T.S., Population-level effects of risk factors for bovine respiratory disease in Australian feedlot cattle.Preventive Veterinary Medicine http://dx.doi.org/10. 1016/j.prevetmed.2017.03.001 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. HighlightsPopulation-level effects of risk factors for BRD in feedlot cattle were determined Risk factors with large effects were shared pen water, breed, mixing and move timing BVDV in the pen, prior group size and weight had moderate or modest effects 82% of BRD incidence was attributed to management-related risk factors 2 AbstractResults obtained from a nationwide longitudinal study were extended to estimate the population-level effects of selected risk factors on the incidence of bovine respiratory disease (BRD) during the first 50 days at risk in medium-sized to large Australian feedlots.Population attributable fractions (PAF) and population attributable risks (PAR) were used to rank selected risk factors in order of importance from the perspective of the Australian feedlot industry within two mutually exclusive categories: 'intervention' risk factors had practical strategies that feedlot managers could implement to avoid exposure of cattle to adverse levels of the risk factor and a precise estimate of the population-level effect while 'others' did not. An alternative method was also used to quantify the expected effects of simultaneously preventing exposure to multiple management-related factors whilst not changing exposure to factors that were more difficult to modify. Other important risk factors identified and prioritised for further research were feedlot region, season of induction and cohort formation patterns.3 An estimated 82% of BRD incidence was attributable to management-related risk factors, whereby the lowest risk category of a composite management-related variable comprised animals in the lowest risk category of at least four of the five component variables (shared pen water, mixing, move timing, BVDV-1 in the cohort and the number of animals in the animal's group-13). This indicated that widespread adoption of appropriate interventions including ensuring pen water is not shared between pens, optimising animal mixing before induction, timing of the animal's move to the vicinity of the feedlot, and group size prior to placing animals in feedlot pens, and avoiding BVDV-1 in cohorts could markedly reduce the incidence of BRD in medium-sized to large Australian feedlots.

An Evaluation of Temporal Distributions of High, Low, and Zero Cohort Morbidity of Cumulative First Treatment Bovine Respiratory Disease and Their Associations with Demographic, Health, and Performance Outcomes in US Feedlot Cattle

“…Shrink was lowest in cohorts reporting no BRD morbidities (ZERO) and highest in HIGH (H1 through H5) cluster groups. Findings showing higher levels of shrink associated with higher morbidity were similar to previous research, which reported that cattle with greater shrink (body weight loss from purchase to feedlot arrival) had greater BRD morbidity risk as well as lower arrival body weights [ 19 , 20 ]. The authors suggested this was likely due to the stress incurred during transport and distance traveled.…”

Re-Introduction of Bovine Viral Diarrhea Virus in a Disease-Free Region: Impact on the Affected Cattle Herd and Diagnostic Implications

“…While a major animal health and welfare impact of BVDV originates from the birth of PI calves that often succumb to the virus' late-onset form of the inevitably fatal MD, BVDV is also described to be a key pathogen in the multifactorial bovine respiratory disease (BRD) complex [36][37][38]. Therefore, the clinical signs indicative of a respiratory disease that were observed during the period in which the PI calves were present in the study herd might be related to BVDV.…”

Ruminant health research – progress to date and future prospects, with an emphasis on Irish research

“…Bovine respiratory disease is the most prevalent disease of recently weaned beef calves in Ireland, accounting for 34.3% of deaths in calves between 1 and 5 mo old (Murray et al, 2017;DAFM, 2019). In addition, BRD is also the most prevalent disease of recently weaned feedlot cattle in Ireland (Murray et al, 2017;Cuevas Gomez et al, 2020) and internationally (Delabouglise et al, 2017;Hay et al, 2017;Wilson et al, 2017) and causes substantial economic losses due to decreased animal performance, higher mortality rates and increased costs associated with treatment (Cernicchiaro et al, 2013;Blakebrough-Hall et al, 2020) as well as negatively impacting animal welfare (Lynch et al, 2011;Wolfger et al, 2015aWolfger et al, , 2015bEarley et al, 2017).…”