BEHAVIORAL EXPRESSION OF LAYING HENS IN AVIARIES AND CAGES - FREQUENCIES, TIME BUDGETS AND FACILITY UTILIZATION

1. We studied: behavioural frequencies and time budgets of behaviour p atterns in non-beak-trimmed White Leghorn layers housed in cages (720 cm(2)/hen, 3 hens/cage), and in the Marielund, the Tiered Wire Floor ( TWF), and the Laco-Voletage aviaries (17 hens/m(2) ground area); indiv idual variation in behaviour among aviary hens; spatial utilisation of the different types of aviary. 2. At 25, 40, and 60 weeks of age beha viour patterns of 114 focal animals were data logged. Each bird was ob served for 10 min 4 times a day on three consecutive days. 3. The freq uency of activity transitions and the activity level was highest in TW F, second highest in cages, and lowest in Laco-Voletage, suggested tha t Laco-Voletage hens were the calmest, whereas birds in cages and in T WF were more restless. Abnormal types of behaviour occurred most often in cages and TWF. The disadvantageous behaviour patterns shown by bir ds in TWF and cages imply that these environments were the least appro priate for this layer strain. 4. Pronounced individual variations in m obility and facility utilisation were found, both within and between t he three aviaries. Resting levels were used twice as much (Laco-Voleta ge), and litter areas one third as much (Marielund), as that expected on a simple a proportionate basis. Most feather pecking was performed at resting levels and on feeding floors, whereas most agonistic behavi our patterns were observed on feeding floors and litter. 5. Measures t o improve the aviaries are outlined.