Stocking Density Affects Stress and Anxious Behavior in the Laying Hen Chick During Rearing.

Autor: Eugen KV; Behavior and Welfare Group, Department of Farm Animal Health, Faculty of Veterinary Medicine, Utrecht University, Utrecht, the Netherlands. sarah.voneugen@ruhr-uni-bochum.de.; Biopsychology, Institute of Cognitive Neuroscience, Faculty of Psychology, Ruhr-University Bochum, Bochum, Germany. sarah.voneugen@ruhr-uni-bochum.de., Nordquist RE; Behavior and Welfare Group, Department of Farm Animal Health, Faculty of Veterinary Medicine, Utrecht University, Utrecht, the Netherlands. r.e.nordquist1@uu.nl., Zeinstra E; Behavior and Welfare Group, Department of Farm Animal Health, Faculty of Veterinary Medicine, Utrecht University, Utrecht, the Netherlands. e.c.zeinstra@uu.nl., Staay FJV; Behavior and Welfare Group, Department of Farm Animal Health, Faculty of Veterinary Medicine, Utrecht University, Utrecht, the Netherlands. F.J.vanderStaay@uu.nl.
Jazyk: angličtina
Zdroj: Animals : an open access journal from MDPI [Animals (Basel)] 2019 Feb 10; Vol. 9 (2). Date of Electronic Publication: 2019 Feb 10.
DOI: 10.3390/ani9020053
Abstrakt: The recent increases in stocking density, in extreme cases resulting in 'crowding', have a major impact on poultry welfare. In contrast to available research on adult laying hens, there is a gap in the literature studying the rearing phase. The present study investigated the effects of stocking density during the rearing period on the welfare of the laying hen chick. The chicks were housed under one of three crowding conditions, increasing with age: undercrowding (500-1000-1429 cm² per chick), conventional crowding (167-333-500 cm² per chick), or overcrowding (56-111-167 cm² per chick). The parameters evaluated encompassed behavioral and physiological factors related to anxiety and stress. We found that during the first 6 weeks, overcrowded chicks displayed more anxious behavior than undercrowded chicks, and both extreme densities induced higher corticosterone levels compared to chicks housed under conventional crowding. At 10 weeks of age, plasma corticosterone had dropped to the level of conventional crowding group in both groups, whereas feather corticosterone remained high only in the overcrowded group. We conclude that current conventional stocking densities do not seem to impair the welfare state of the laying hen chick, and that a three-fold increase or decrease of density influences corticosterone levels and anxious behavior, but within the adaptive capacity of the chick. Important side notes to this conclusion are that an increase of stocking density did result in a slower rate of adaptation, and that there could be long-term consequences of both the different stocking densities and/or increased costs of adaptation.
Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
Databáze: MEDLINE
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