title: Treating cattle with antibiotics affects greenhouse gas emissions, and microbiota in dung and dung beetles.
abstract: Antibiotics are routinely used to improve livestock health and growth. However, this practice may have unintended environmental impacts mediated by interactions among the wide range of micro- and macroorganisms found in agroecosystems. For example, antibiotics may alter microbial emissions of greenhouse gases by affecting livestock gut microbiota. Furthermore, antibiotics may affect the microbiota of non-target animals that rely on dung, such as dung beetles, and the ecosystem services they provide. To examine these interactions, we treated cattle with a commonly used broad-spectrum antibiotic and assessed downstream effects on microbiota in dung and dung beetles, greenhouse gas fluxes from dung, and beetle size, survival and reproduction. We found that antibiotic treatment restructured microbiota in dung beetles, which harboured a microbial community distinct from those in the dung they were consuming. The antibiotic effect on beetle microbiota was not associated with smaller size or lower numbers. Unexpectedly, antibiotic treatment raised methane fluxes from dung, possibly by altering the interactions between methanogenic archaea and bacteria in rumen and dung environments. Our findings that antibiotics restructure dung beetle microbiota and modify greenhouse gas emissions from dung indicate that antibiotic treatment may have unintended, cascading ecological effects that extend beyond the target animal.
authors.affiliation: Department of Ecology and Evolutionary Biology, University of Colorado at Boulder, Boulder, CO, USA Cooperative Institute for Research in Environmental Sciences, University of Colorado at Boulder, Boulder, CO, USA tobin.hammer@colorado.edu.
authors.forename: Tobin J
authors.identifier: 0000-0002-7308-8440
authors.initials: TJ
authors.lastname: Hammer
authors.affiliation: Department of Ecology and Evolutionary Biology, University of Colorado at Boulder, Boulder, CO, USA Cooperative Institute for Research in Environmental Sciences, University of Colorado at Boulder, Boulder, CO, USA.
authors.forename: Noah
authors.initials: N
authors.lastname: Fierer
authors.affiliation: Spatial Foodweb Ecology Group, Department of Agricultural Sciences, University of Helsinki, Helsinki, Finland.
authors.forename: Bess
authors.initials: B
authors.lastname: Hardwick
authors.affiliation: Department of Food and Environmental Sciences, University of Helsinki, Helsinki, Finland.
authors.forename: Asko
authors.initials: A
authors.lastname: Simojoki
authors.affiliation: Spatial Foodweb Ecology Group, Department of Agricultural Sciences, University of Helsinki, Helsinki, Finland Department of Zoology, University of Oxford, South Parks Road, Oxford, UK Lancaster Environment Centre, University of Lancaster, Lancaster, UK.
authors.forename: Eleanor
authors.initials: E
authors.lastname: Slade
authors.affiliation: Department of Production Animal Medicine, University of Helsinki, Saarentaus, Finland.
authors.forename: Juhani
authors.initials: J
authors.lastname: Taponen
authors.affiliation: Spatial Foodweb Ecology Group, Department of Agricultural Sciences, University of Helsinki, Helsinki, Finland Metapopulation Research Centre, Department of Biosciences, University of Helsinki, Helsinki, Finland.
authors.forename: Heidi
authors.initials: H
authors.lastname: Viljanen
authors.affiliation: Spatial Foodweb Ecology Group, Department of Agricultural Sciences, University of Helsinki, Helsinki, Finland Department of Ecology, Swedish University of Agricultural Sciences, Uppsala, Sweden.
authors.forename: Tomas
authors.initials: T
authors.lastname: Roslin
mesh_terms: D000393:Air Pollutants / Q000378:metabolism*; D000818:Animals; D000900:Anti-Bacterial Agents / Q000008:administration & dosage*; D049628:Body Size; D002245:Carbon Dioxide / Q000378:metabolism; D002417:Cattle / Q000378:metabolism*; D001517:Coleoptera / Q000235:genetics / Q000382:microbiology* / Q000502:physiology; D005243:Feces / Q000737:chemistry / Q000382:microbiology*; D005740:Gases; D056084:Genetic Fitness; D017752:Greenhouse Effect; D008697:Methane / Q000378:metabolism; D064307:Microbiota / Q000187:drug effects*; D009609:Nitrous Oxide / Q000378:metabolism; D011156:Population Density
chemical_list: D000393:Air Pollutants; D000900:Anti-Bacterial Agents; D005740:Gases; D002245:Carbon Dioxide; D009609:Nitrous Oxide; D008697:Methane
keywords: antimicrobial; greenhouse gases; insect; methane; microbiome