Increased mortality in groups of cattle administered the β-adrenergic agonists ractopamine hydrochloride and zilpaterol hydrochloride

K-REx Repository

Show simple item record Loneragan, Guy H. Thomson, Daniel U. Scott, Harvey Morgan 2014-05-27T18:20:56Z 2014-05-27T18:20:56Z 2014-03-12
dc.description.abstract The United States Food and Drug Administration (FDA) approved two β-adrenergic agonists (βAA) for in-feed administration to cattle fed in confinement for human consumption. Anecdotal reports have generated concern that administration of βAA might be associated with an increased incidence of cattle deaths. Our objectives, therefore, were to a) quantify the association between βAA administration and mortality in feedlot cattle, and b) explore those variables that may confound or modify this association. Three datasets were acquired for analysis: one included information from randomized and controlled clinical trials of the βAA ractopamine hydrochloride, while the other two were observational data on zilpaterol hydrochloride administration to large numbers of cattle housed, fed, and cared for using routine commercial production practices in the U.S. Various population and time at-risk models were developed to explore potential βAA relationships with mortality, as well as the extent of confounding and effect modification. Measures of effect were relatively consistent across datasets and models in that the cumulative risk and incidence rate of death was 75 to 90% greater in animals administered the βAA compared to contemporaneous controls. During the exposure period, 40 to 50% of deaths among groups administered the βAA were attributed to administration of the drug. None of the available covariates meaningfully confounded the relationship between βAA and increased mortality. Only month of slaughter, presumably a proxy for climate, consistently modified the effect in that the biological association was generally greatest during the warmer months of the year. While death is a rare event in feedlot cattle, the data reported herein provide compelling evidence that mortality is nevertheless increased in response to administration of FDA-approved βAA and represents a heretofore unquantified adverse drug event. en_US
dc.language.iso en_US en_US
dc.relation.uri en_US
dc.subject Cattle en_US
dc.subject Ractopamine hydrochloride en_US
dc.subject Zilpaterol hydrochloride en_US
dc.subject B-adrenergic agonists en_US
dc.subject β-adrenergic agonists en_US
dc.title Increased mortality in groups of cattle administered the β-adrenergic agonists ractopamine hydrochloride and zilpaterol hydrochloride en_US
dc.type Article (publisher version) en_US 2014 en_US
dc.citation.doi 10.1371/journal.pone.0091177 en_US
dc.citation.issue 3 en_US
dc.citation.jtitle PLoS ONE en_US
dc.citation.spage e91177 en_US
dc.citation.volume 9 en_US
dc.contributor.authoreid thomson en_US
dc.contributor.authoreid hmscott en_US

Files in this item

This item appears in the following Collection(s)

Show simple item record

Search K-REx

Advanced Search


My Account


Center for the

Advancement of Digital