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 fa