Comparative study on the behaviour, health and productivity of laying hens in a furnished cage and an aviary system.

A total of 540 Lohmann Silver laying hens was used to investigate behaviour, use of the structural elements offered, as well as health and productive parameters in six units (45 hens each) of one furnished cage system (FC; Typ 715/725, Fa. Salmet, Berge, Germany, according to EU guideline 1999/74/EG [2003]) vs. three units (90 hens each) of one aviary housing system (AV; type natura, Big Dutchman, Vechta, Germany). There was no difference between the two systems in terms of animal health, egg quality, laying performance and nest acceptance Acceptance of the nests was high in both systems and resulted in relatively small proportions of mislaid eggs (median 0.28% AV vs. 0.33% FC). Perches in FC were used during the light phase by 15.6% of the hens compared with 73.3% at night. The dust bathing activity of the hens in AV corresponded to natural circadian behaviour patterns (P <0.003) and the complete behaviour chain was exhibited. In contrast, FC hens invariably exhibited incomplete dust bathing patterns on the mat and on the grid floor without any diurnal rhythm. Duration of dust bathing of hens in FC differed significantly from the AV hens (median value 4.77 minutes on mats and 4.62 on grid floors respectively vs. 14.87 minutes, P < 0.05). Even though comparison of laying performance, egg quality and health did not yield any serious disadvantage of one system over the other, it has to be taken into consideration that normal behaviour was highly restricted in FC.