The impact of scheduled cage cleaning on older hens (Gallus gallus)

Researchers are increasingly using the domestic hen (Gallus gallus) as an animal model for ovarian cancer. The authors analyzed mortality rates of two large flocks of older hens that were being used for ovarian adenocarcinoma studies. All hens were fed the same maintenance diets, though some hens in each flock received experimental chemopreventive treatments. Per the request of a collaborating institution, partway through the study, the authors started to remove the hens in one of the flocks for cage changing once every 4 weeks. After the authors began cleaning some of the hens' cages, the mortality rate in this flock increased significantly. Throughout the study, within each flock, hens in the treatment and control groups had similar mortality rates. These results suggest that regularly cleaning the cages of older hens may not promote better welfare or improve flock mortality.