title: Evaluation of the relationship between the biosecurity status, production parameters, herd characteristics and antimicrobial usage in farrow-to-finish pig production in four EU countries.
abstract: BACKGROUND
  High antimicrobial usage and the threat of antimicrobial resistance highlighted the need for reduced antimicrobial usage in pig production. Prevention of disease however, is necessary to obtain a reduced need for antimicrobial treatment. This study aimed at assessing possible associations between the biosecurity level, antimicrobial usage and farm and production characteristics in order to advice on best practices for a low antimicrobial usage and maximum animal health and production. A cross-sectional study was conducted in 227 farrow-to-finish pig herds in Belgium, France, Germany and Sweden between December 2012 and December 2013. Associations between biosecurity status, antimicrobial usage, and production parameters were evaluated with multivariable general linear models, according to an assumed causal pathway.
  
  
  RESULTS
  The results showed that higher antimicrobial usage in sows tended to be associated with higher antimicrobial usage from birth until slaughter (p= 0.06). The antimicrobial usage from birth until slaughter was positively associated with the number of pathogens vaccinated against (p< 0.01). A shorter farrowing rhythm (p< 0.01) and a younger weaning age (p= 0.06) tended to be also associated with a higher antimicrobial usage from birth until slaughter whereas a better external biosecurity (p< 0.01) was related with a lower antimicrobial usage from birth until slaughter.
  
  
  CONCLUSIONS
  Management practices such as weaning age and biosecurity measures may be important factors indirectly impacting on antimicrobial usage. We therefore promote a holistic approach when assessing the potential to reduce the need for antimicrobial treatments.
authors.affiliation: Veterinary Epidemiology Unit, Department of Reproduction, Obstetrics and Herd Health, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium.
authors.forename: Merel
authors.initials: M
authors.lastname: Postma
authors.affiliation: Department of Animal Health and Antimicrobial Strategies, National Veterinary Institute, SVA, SE-751 89 Uppsala, Sweden.|Department of Clinical Sciences, Swedish University of Agricultural Sciences, P.O. Box 7054, SE-750 07 Uppsala, Sweden.
authors.forename: Annette
authors.initials: A
authors.lastname: Backhans
authors.affiliation: SAFOSO AG, Waldeggstrasse 1, CH-3097 Liebefeld, Switzerland.|UMR1300 BioEpAR, LUNAM Université, Oniris, INRA, BP40706, F-44307 Nantes, France.
authors.forename: Lucie
authors.initials: L
authors.lastname: Collineau
authors.affiliation: Field Station for Epidemiology, University of Veterinary Medicine Hannover, Büscheler Straße 9, D-49456 Bakum, Germany.
authors.forename: Svenja
authors.initials: S
authors.lastname: Loesken
authors.affiliation: Department of Animal Health and Antimicrobial Strategies, National Veterinary Institute, SVA, SE-751 89 Uppsala, Sweden.|Department of Clinical Sciences, Swedish University of Agricultural Sciences, P.O. Box 7054, SE-750 07 Uppsala, Sweden.
authors.forename: Marie
authors.initials: M
authors.lastname: Sjölund
authors.affiliation: UMR1300 BioEpAR, LUNAM Université, Oniris, INRA, BP40706, F-44307 Nantes, France.
authors.forename: Catherine
authors.initials: C
authors.lastname: Belloc
authors.affiliation: Department of Clinical Sciences, Swedish University of Agricultural Sciences, P.O. Box 7054, SE-750 07 Uppsala, Sweden.
authors.forename: Ulf
authors.initials: U
authors.lastname: Emanuelson
authors.affiliation: Field Station for Epidemiology, University of Veterinary Medicine Hannover, Büscheler Straße 9, D-49456 Bakum, Germany.
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Grosse Beilage
authors.affiliation: Danish Agriculture and Food Council, Axeltorv 3, DK-1609 Copenhagen V, Denmark.
authors.forename: Elisabeth Okholm
authors.initials: EO
authors.lastname: Nielsen
authors.affiliation: SAFOSO AG, Waldeggstrasse 1, CH-3097 Liebefeld, Switzerland.
authors.forename: Katharina D C
authors.initials: KDC
authors.lastname: Stärk
authors.affiliation: Veterinary Epidemiology Unit, Department of Reproduction, Obstetrics and Herd Health, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium.
authors.forename: Jeroen
authors.initials: J
authors.lastname: Dewulf
keywords: Antimicrobial usage; Biosecurity; Causal path; Pig production; Production parameters