DICHOTOMY IN CHOICE OF NEST CHARACTERISTICS BY CAGED LAYING HENS

Soiling of nests in modified cages for laying hens might be reduced by using a wire mesh floor for the nest. However, use of such a material might be contrary to the preferences of the hens and compromise their welfare. Twenty-four laying hens were housed singly in modified cages which incorporated two nests. One nest had the standard perforated plastic floor whilst the other had one of two types of metal mesh floor. To determine whether hens preferred any one of the floor types for oviposition, the positions of the nest floors were swapped three times during 110 days. The hens showed a dichotomy in their behaviour after the nest floors were swapped: the majority (12 of those making a consistent choice) continued to lay in the same nest location (ie location conservative) whereas 6-9 hens changed the nest in which they laid (ie floor type conservative). Only one of the floor type conservative hens preferred to lay on metal mesh. These results show that although the majority of hens showed no apparent aversion to laying in nests with metal mesh floors, 57-68 per cent preferred plastic floors and changed location to lay on this substrate.