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United States Department of Agriculture

Agricultural Research Service

Research Project: Safeguarding Well-being of Food Producing Animals

Location: Livestock Behavior Research

Title: The effect of perch access during pullet rearing and egg laying on physiological measurements of stress in 71-week-old White Leghorns

Authors
item Yan, Feifei -
item Hester, Patricia -
item Dennis, Rachel
item Cheng, Heng Wei

Submitted to: Poultry Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: March 18, 2014
Publication Date: May 19, 2014
Citation: Yan, F., Hester, P.Y., Dennis, R.L., Cheng, H. 2014. The effect of perch access during pullet rearing and egg laying on physiological measurements of stress in 71-week-old White Leghorns. Poultry Science. 93(6):1318-1326.

Interpretive Summary: Most of the research on the effects of perch access in hens has focused on their behavior, productivity, and skeletal health. Little is known about the influence of perch usage on the stress response of hens. The objective of this study was to investigate the effect of perch access during all or part of the life cycle on the stress response of caged 71-wk-old White Leghorn hens. The birds' physical and physiological changes associated with perch access were measured. Results showed there was no perch effects on the stress response of hens except for shank width. Chickens with previous exposure to perches during the pullet phase had wider shanks than chickens without access to perches. These data suggest that modification of conventional cages with perches did not cause stress in hens, and it may inprove skeletal health in chickens. These results can be used by egg producers to develop management guidelines for improving pullet and hen welfare by providing perches.

Technical Abstract: Egg laying strains of chickens have a strong motivation to perch. Providing caged chickens with perches allows them to perform their natural perching instinct and also improves their musculoskeletal health due to exercise. Little is known about the effect of perch access by hens on physiological measurements of stress. Our hypothesis was that denying chicken access to perches would elicit a stress response. The objective of this study was to determine the effect of perch access during all or part of life cycle on physiological homeostasis in caged 71-wk-old White Leghorn hens. Chickens were randomly assigned to 2 groups, 14 cages each with and without perches, from hatch to 16.9 wk of age. At 17 wk of age, the chickens were further assigned randomly to 1 of 4 treatments with 9 replicates per treatment. Treatment 1 chickens never had access to perches during their life cycle. Treatment 2 chickens had access to perches only from 17 to 71 wk of age (laying phase). Treatment 3 chickens had access to perches only from hatch to 16.9 wk of age (pullet phase). Treatment 4 chickens always had access to perches during their life cycle. At 71 wk of age, 2 chickens per cage were sampled randomly for measurement of plasma catecholamines (epinephrine, norepinephrine, and dopamine) and corticosterone; blood serotonin and tryptophan; and shank length and width. The right adrenal weight was determined in 8 to 9 hens per cage and expressed relative to BW. Only shank width differed among treatments. Chickens with previous exposure to perches during the pullet phase had wider shanks than chickens without access to perches (P = 0.006). These results suggest that 71-wk-old White Leghorn hens that never had access to perches showed no evidence of eliciting a stress response.

Last Modified: 10/20/2014
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