A DESCRIPTIVE ACCOUNT OF THE PRELAYING BEHAVIOR OF HENS HOUSED INDIVIDUALLY IN MODIFIED CAGES WITH NESTS

Incorporating nests into modified cages for laying hens might overcome some of the welfare concerns about conventional cages, though detailed behavioural studies of pre-laying in such systems must first be conducted to assess their suitability. The present study describes the pre-laying behaviour of 24 hens housed singly in modified cages, each containing two nests and compares this with pre-laying behaviour reported previously for hens in other husbandry systems. Generally, hens in the modified cages expressed a full repertoire of pre-laying activities. Displacement behaviours and pacing (usually considered as indicators of frustration) were less frequent than in conventional cages. Sleeping, sitting on the nest, nest-building behaviours and crouching were all more similar to those in extensive systems than to those observed in conventional cages. Nest entries and inspections were relatively infrequent. The modified cages appeared to be more acceptable on welfare grounds than conventional cages without nests, however, the abnormal behaviour of some hens indicated considerable individual differences existed which must be considered in future designs.