title: Investigations on the possible impact of a glyphosate-containing herbicide on ruminal metabolism and bacteria in vitro by means of the 'Rumen Simulation Technique'.
abstract: OBJECTIVE
  This study was performed in a well-established in vitro model to investigate whether the application of a glyphosate-containing herbicide might affect the bacterial communities and some biochemical parameters in a cow's rumen.
  
  
  RESULTS
  The test item was applied in two concentrations (high and low) for 5 days. In a second trial, fermentation vessels were inoculated with Clostridium sporogenes before the high dose was applied. Effluents were analysed by biochemical, microbiological and genetic methods. A marginal increase in short-chain fatty acid production and a reduction in NH3 -N were observed. There were minor and rather equivocal changes in the composition of ruminal bacteria but no indications of a shift towards a more frequent abundance of pathogenic Clostridia species. Clostridium sporogenes counts declined consistently.
  
  
  CONCLUSIONS
  No adverse effects of the herbicide on ruminal metabolism or composition of the bacterial communities could be detected. In particular, there was no evidence of a suspected stimulation of Clostridia growth.
  
  
  CONCLUSIONS
  Antibiotic activity of glyphosate resulting in microbial imbalances has been postulated. In this exploratory study, however, intraruminal application of concentrations reflecting potential exposure of dairy cows or beef cattle did not exhibit significant effects on bacterial communities in a complex in vitro system. The low number of replicates (n = 3/dose) may leave some uncertainty.
authors.affiliation: Department of Physiology, University of Veterinary Medicine, Hannover, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Riede
authors.affiliation: Federal Institute for Risk Assessment, Berlin, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Toboldt
authors.affiliation: Department of Physiology, University of Veterinary Medicine, Hannover, Germany.
authors.forename: G
authors.initials: G
authors.lastname: Breves
authors.affiliation: RIPAC-LABOR GmbH, Potsdam, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Metzner
authors.affiliation: RIPAC-LABOR GmbH, Potsdam, Germany.
authors.forename: B
authors.initials: B
authors.lastname: Köhler
authors.affiliation: Federal Institute for Risk Assessment, Berlin, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Bräunig
authors.affiliation: Federal Institute for Risk Assessment, Berlin, Germany.
authors.forename: H
authors.initials: H
authors.lastname: Schafft
authors.affiliation: Federal Institute for Risk Assessment, Berlin, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Lahrssen-Wiederholt
authors.affiliation: Federal Institute for Risk Assessment, Berlin, Germany.
authors.forename: L
authors.initials: L
authors.lastname: Niemann
mesh_terms: D000818:Animals; D001419:Bacteria / Q000145:classification* / Q000378:metabolism; D002417:Cattle / Q000378:metabolism* / Q000382:microbiology; D003013:Clostridium / Q000145:classification / Q000187:drug effects / Q000254:growth & development*; D004032:Diet; D005227:Fatty Acids / Q000032:analysis; D005260:Female; D005285:Fermentation; D005750:Gastric Juice / Q000382:microbiology; D000069196:Gastrointestinal Microbiome / Q000187:drug effects*; D005998:Glycine / Q000031:analogs & derivatives* / Q000633:toxicity; D006540:Herbicides / Q000633:toxicity*; D066298:In Vitro Techniques; D012417:Rumen / Q000378:metabolism* / Q000382:microbiology; D000097797:Glyphosate
chemical_list: D005227:Fatty Acids; D005998:Glycine; D006540:Herbicides; D000097797:Glyphosate
keywords: Clostridia; Rumen Simulation Technique; glyphosate; microbial communities; ruminal metabolism