title: Specific characteristics of the aviary housing system affect plumage condition, mortality and production in laying hens.
abstract: Feather pecking and high mortality levels are significant welfare problems in non-cage housing systems for laying hens. The aim of this study was to identify husbandry-related risk factors for feather damage, mortality, and egg laying performance in laying hens housed in the multi-tier non-cage housing systems known as aviaries. Factors tested included type of system flooring, degree of red mite infestation, and access to free-range areas. Information on housing characteristics, management, and performance in Belgian aviaries (N=47 flocks) were obtained from a questionnaire, farm records, and farm visits. Plumage condition and pecking wounds were scored in 50 randomly selected 60-week-old hens per flock. Associations between plumage condition, wounds, performance, mortality, and possible risk factors were investigated using a linear model with a stepwise model selection procedure. Many flocks exhibited a poor plumage condition and a high prevalence of wounds, with considerable variation between flocks. Better plumage condition was found in wire mesh aviaries (P<0.001), in aviaries with no red mite infestation (P=0.004), and in free-range systems (P=0.011) compared to plastic slatted aviaries, in houses with red mite infestations, and those without a free-range area. Furthermore, hens in aviaries with wire mesh flooring had fewer wounds on the back (P=0.006) and vent (P=0.009), reduced mortality (P=0.003), and a better laying performance (P=0.013) as compared to hens in aviaries with plastic slatted flooring. Flocks with better feather cover had lower levels of mortality (P<0.001). Red mite infestations were more common in plastic slatted aviaries (P=0.043). Other risk factors associated with plumage condition were genotype, number of diet changes, and the presence of nest perches. Wire mesh flooring in particular seems to have several health, welfare, and performance benefits in comparison to plastic slats, possibly related to decreased feather pecking, better hygiene, and fewer red mite infestations. This suggests that adjustments to the aviary housing design may further improve laying hen welfare and performance.
authors.affiliation: Animal Sciences Unit, Institute for Agricultural and Fisheries Research (ILVO), Scheldeweg 68, B-9090 Melle, Belgium jasper.heerkens@ilvo.vlaanderen.be.
authors.forename: Jasper L T
authors.initials: JL
authors.lastname: Heerkens
authors.affiliation: Animal Sciences Unit, Institute for Agricultural and Fisheries Research (ILVO), Scheldeweg 68, B-9090 Melle, Belgium.
authors.forename: Evelyne
authors.initials: E
authors.lastname: Delezie
authors.affiliation: Experimental Poultry Centre, Poiel 77, B-2440 Geel, Belgium.
authors.forename: Ine
authors.initials: I
authors.lastname: Kempen
authors.affiliation: Experimental Poultry Centre, Poiel 77, B-2440 Geel, Belgium.
authors.forename: Johan
authors.initials: J
authors.lastname: Zoons
authors.affiliation: Animal Sciences Unit, Institute for Agricultural and Fisheries Research (ILVO), Scheldeweg 68, B-9090 Melle, Belgium.
authors.forename: Bart
authors.initials: B
authors.lastname: Ampe
authors.affiliation: Behavioural Ecology Group, Wageningen University, P.O. Box 338, 6700 AH Wageningen, The Netherlands.
authors.forename: T Bas
authors.initials: TB
authors.lastname: Rodenburg
authors.affiliation: Animal Sciences Unit, Institute for Agricultural and Fisheries Research (ILVO), Scheldeweg 68, B-9090 Melle, Belgium Ghent University, Faculty of Veterinary Medicine, Salisburylaan 133, B-9820 Merelbeke, Belgium.
authors.forename: Frank A M
authors.initials: FA
authors.lastname: Tuyttens
mesh_terms: D000827:Animal Welfare; D000818:Animals; D001530:Belgium / Q000453:epidemiology; D002645:Chickens; D005241:Feathers / Q000473:pathology; D005260:Female; D006799:Housing, Animal / Q000592:standards*; D011201:Poultry Diseases / Q000453:epidemiology* / Q000209:etiology / Q000401:mortality; D012098:Reproduction / Q000502:physiology; D012307:Risk Factors
keywords: aviary; feather pecking; housing system; mortality; red mite