Sixty 51-day-old male rabbits were divided into three experimental
groups of 20 rabbits of similar average body weights and reared in wire
net floor colony cages at the same group size (4 animals/cage) but at
different stocking density as follows: 16 rabbits/m2 (cage size:
cm 50×50×76 h), 5 rabbits/m2 (cage size: cm 100×80×76 h) and
2.5 rabbits/m2 (cage size: cm 100×160×76 h). Cages were located in
an outdoor pen built to provide the animals with protection against
predators and the radiation of the sun.