Effect of two floor housing systems and cages on health, production, and fear response in layers

Health, production, and fear reaction (tonic immobility) were compared in t wo non-beak-trimmed hybrids (1726 birds), a medium-heavy brown (LB) and a l ight white Leghorn (LSL), kept in three housing systems: a three-tiered "Ma rielund aviary", a traditional floor system, or conventional three-hen cage s from 20-80 wk of age. LB hens showed mortality rates of 21-27% in both fl oor systems, mainly due to bacterial infection through pecking at the naked skin, while mortality reached only 7% in cages. The LSL showed moderate mo rtality (6-10%) regardless of system. Due to corresponding amounts of feath er pecking, there were 10% increases in feed intake due to poor feather ins ulation of the body. The proportion of cracked and dirty eggs was lower in the traditional floor system than in cages for LSL birds; the proportion of misplaces eggs was similar in the aviary and the traditional system for LS L, but higher for the LB in the aviary. Birds had more bumble foot, keel bo ne deviation, and inferior hygiene of feet and plumage but less hyperkerato sis in the floor systems than in cages. Tonic immobility duration in birds did not differ between systems, but the LSL needed fewer induction repetiti ons than the LB. The non-break-trimmed LB apparently experiences social dis turbance leading to pecking when kept in large groups, i.e., non-cage syste ms. There may be little difference in health between birds in an aviary sys tem and a traditional floor system.