title: A 10-day vacancy period after cleaning and disinfection has no effect on the bacterial load in pig nursery units.
abstract: BACKGROUND
  Biosecurity measures such as cleaning, disinfection and a vacancy period between production cycles on pig farms are essential to prevent disease outbreaks. No studies have tested the effect of a longer vacancy period on bacterial load in nursery units.
  
  
  METHODS
  The present study evaluated the effect of a 10-day vacancy period in pig nursery units on total aerobic flora, Enterococcus spp., Escherichia coli, faecal coliforms and methicillin resistant Staphylococcus aureus (MRSA). Three vacancy periods of 10 days were monitored, each time applied in 3 units. The microbiological load was measured before disinfection and at 1, 4, 7 and 10 days after disinfection.
  
  
  RESULTS
  No significant decrease or increase in E. coli, faecal coliforms, MRSA and Enterococcus spp. was noticed. Total aerobic flora counts were the lowest on day 4 after disinfection (i.e. 4.07 log CFU/625 cm2) (P < 0.05), but the difference with other sampling moments was limited (i.e. 0.6 log CFU/625 cm2) and therefore negligible. Furthermore, this observation on day 4 was not confirmed for the other microbiological parameters. After disinfection, drinking nipples were still mostly contaminated with total aerobic flora (i.e. 5.32 log CFU/625 cm2) and Enterococcus spp. (i.e. 95 % of the samples were positive) (P < 0.01); the feeding troughs were the cleanest location (total aerobic flora: 3.53 log CFU/625 cm2and Enterococcus spp.: 50 % positive samples) (P < 0.01).
  
  
  CONCLUSIONS
  This study indicates that prolonging the vacancy period in nursery units to 10 days after disinfection with no extra biosecurity measures has no impact on the environmental load of total aerobic flora, E. coli, faecal coliforms, MRSA and Enterococcus spp..
authors.affiliation: Institute for Agricultural and Fisheries Research (ILVO), Merelbeke, Belgium.
authors.forename: K
authors.initials: K
authors.lastname: Luyckx
authors.affiliation: Institute for Agricultural and Fisheries Research (ILVO), Merelbeke, Belgium.
authors.forename: S
authors.initials: S
authors.lastname: Millet
authors.affiliation: Institute for Agricultural and Fisheries Research (ILVO), Merelbeke, Belgium.
authors.forename: S
authors.initials: S
authors.lastname: Van Weyenberg
authors.affiliation: Institute for Agricultural and Fisheries Research (ILVO), Merelbeke, Belgium.
authors.forename: L
authors.initials: L
authors.lastname: Herman
authors.affiliation: Institute for Agricultural and Fisheries Research (ILVO), Merelbeke, Belgium.|Department of Pathology, Bacteriology and Poultry Diseases, Ghent University, Faculty of Veterinary Medicine, Merelbeke, Belgium.
authors.forename: M
authors.initials: M
authors.lastname: Heyndrickx
authors.affiliation: Veterinary Epidemiology Unit, Department of Reproduction, Obstetrics and Herd Health, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium.
authors.forename: J
authors.initials: J
authors.lastname: Dewulf
authors.affiliation: Institute for Agricultural and Fisheries Research (ILVO), Merelbeke, Belgium. koen.dereu@ilvo.vlaanderen.be.
authors.forename: K
authors.initials: K
authors.lastname: De Reu
mesh_terms: D000822:Animal Husbandry / Q000379:methods* / Q000592:standards; D000818:Animals; D058491:Bacterial Load / Q000662:veterinary*; D018407:Bacterial Physiological Phenomena; D004203:Disinfection / Q000379:methods* / Q000592:standards*; D006799:Housing, Animal / Q000592:standards*; D013552:Swine; D013997:Time Factors
keywords: Bacterial load; Between batch vacancy; Cleaning and disinfection; Nursery pigs