Cage or free range hens?
23 March 2012
Free range hens are not necessarily less stressed than cage or barn housed hens, a new study from the Faculty of Veterinary Scienceat the University of Sydney has found.
Researcher Dr Jeff Downing, from the Faculty of Veterinary Science, said his study did not point to one particular housing system creating more stress than any other.
Dr Downing analysed levels of corticosterone, a stress hormone found in hens. The study was over 72 weeks and included 12 farms using free range, barn and cage production systems.
"When we combined the results of each housing system there were no statistical differences between corticosterone levels in cage, barn or free range hens," he said.
"We found the variation in corticosterone levels between different farms of the same type of housing system was greater than the variation between housing systems. Regardless of their housing system birds on some farms were showing comparatively low levels of the stress hormone, while birds on other farms were showing higher levels."
Contact: Dr Jeff Downing