This study aimed to evaluate the behavior and the welfare of hens comparing a conventional housing system (laying cages in battery) with another system using litter + nest. The effects of environmental conditions (stress or comfort) on behavior responses of laying hens were also analyzed by precision techniques. Two groups of 10 birds of Hy-line W36 and Hy-line Brown stains, at the beginning of the production phase, were submitted to two environmental conditions (26°C with 60% RU or 35°C with 70% RU) and two housing systems (cages in battery or litter), during two weeks. The birds were marked with non-toxic paint and their behavior was evaluated by tape recorded by video cameras installed on the roof of the climatic chambers. Behavior parameters such as eating, drinking or dustbathing were recorded during 2 hours, in the morning and in the afternoon, in intervals of 1s in order to investigate the frequency and lenght of each parameter. Housing system in litters allowed the expression of all natural behaviors of birds and those related to their comfort, which lead to improve the welfare conditions. The conventional housing system (laying cages) increased stress because birds tried to manifest their natural behavior in the absence of conditions for it.
laying hens; animal behavior; environmental conditions; housing systems
