Rearing conditions and needs for space and litter in laying hens (1991)

Faure, J. M.

Abstract

Many results show that hens in battery cages show abnormal behaviour indicative of frustration. The fact than none of the single factors studies [space, litter] seem to be solely responsible for this frustration may indicate that what is lacking in cages is not a single factor but something more general, such as environmental enrichment.