title: Microbiological impact of three commercial laying hen housing systems.
abstract: Hen housing for commercial egg production continues to be a societal and regulatory concern. Controlled studies have examined various aspects of egg safety, but a comprehensive assessment of commercial hen housing systems in the US has not been conducted. The current study is part of a holistic, multidisciplinary comparison of the diverse aspects of commercial conventional cage, enriched colony cage, and cage-free aviary housing systems and focuses on environmental and egg microbiology. Environmental swabs and eggshell pools were collected from all housing systems during 4 production periods. Total aerobes and coliforms were enumerated, and the prevalence of Salmonella and Campylobacter spp. was determined. Environmental aerobic and coliform counts were highest for aviary drag swabs (7.5 and 4.0 log cfu/mL, respectively) and enriched colony cage scratch pad swabs (6.8 and 3.8 log cfu/mL, respectively). Aviary floor and system wire shell pools had the greatest levels of aerobic contamination for all eggshell pools (4.9 and 4.1 log cfu/mL, respectively). Hens from all housing systems were shedding Salmonella spp. (89-100% of manure belt scraper blade swabs). The dry belt litter removal processes for all housing systems appear to affect Campylobacter spp. detection (0-41% of manure belt scraper blade swabs) considering detection of Campylobacter spp. was much higher for other environmental samples. Aviary forage area drag swabs were 100% contaminated with Campylobacter spp., whereas enriched colony cage scratch pads had a 93% positive rate. There were no differences in pathogen detection in the shell pools from the 3 housing systems. Results indicate egg safety is enhanced when hens in alternative housing systems use nest boxes. Additionally, current outcomes indicate the use of scratch pads in hen housing systems needs to be more thoroughly investigated for effects on hen health and egg safety.
authors.affiliation: USDA, Agricultural Research Service, Russell Research Center, Athens, GA 30605 Deana.Jones@ars.usda.gov.
authors.forename: D R
authors.initials: DR
authors.lastname: Jones
authors.affiliation: USDA, Agricultural Research Service, Russell Research Center, Athens, GA 30605.
authors.forename: N A
authors.initials: NA
authors.lastname: Cox
authors.affiliation: USDA, Agricultural Research Service, Russell Research Center, Athens, GA 30605.
authors.forename: J
authors.initials: J
authors.lastname: Guard
authors.affiliation: USDA, Agricultural Research Service, Russell Research Center, Athens, GA 30605.
authors.forename: P J
authors.initials: PJ
authors.lastname: Fedorka-Cray
authors.affiliation: USDA, Agricultural Research Service, Russell Research Center, Athens, GA 30605.
authors.forename: R J
authors.initials: RJ
authors.lastname: Buhr
authors.affiliation: USDA, Agricultural Research Service, Russell Research Center, Athens, GA 30605.
authors.forename: R K
authors.initials: RK
authors.lastname: Gast
authors.affiliation: USDA, Agricultural Research Service, Russell Research Center, Athens, GA 30605.
authors.forename: Z
authors.initials: Z
authors.lastname: Abdo
authors.affiliation: USDA, Agricultural Research Service, Russell Research Center, Athens, GA 30605.
authors.forename: L L
authors.initials: LL
authors.lastname: Rigsby
authors.affiliation: USDA, Agricultural Research Service, Russell Research Center, Athens, GA 30605.
authors.forename: J R
authors.initials: JR
authors.lastname: Plumblee
authors.affiliation: Department of Animal Science, Michigan State University, East Lansing 48824.
authors.forename: D M
authors.initials: DM
authors.lastname: Karcher
authors.affiliation: Department of Animal Science, Michigan State University, East Lansing 48824.
authors.forename: C I
authors.initials: CI
authors.lastname: Robison
authors.affiliation: Department of Animal Science, University of California, Davis 95616.
authors.forename: R A
authors.initials: RA
authors.lastname: Blatchford
authors.affiliation: Department of Animal Science, Michigan State University, East Lansing 48824.
authors.forename: M M
authors.initials: MM
authors.lastname: Makagon
mesh_terms: D000822:Animal Husbandry / Q000379:methods*; D000827:Animal Welfare; D000818:Animals; D002645:Chickens / Q000382:microbiology* / Q000502:physiology*; D004531:Eggs / Q000382:microbiology*; D004777:Environment; D004783:Environmental Microbiology; D005502:Food / Q000191:economics; D059022:Food Safety; D006799:Housing, Animal; D006801:Humans; D016272:Occupational Health
keywords: Campylobacter; Salmonella; egg; hen housing; microbiology