Effect of Two Floor Housing Systems and Cages on Health, Production, and Fear Response in Layers

Abstract
Health, production, and fear reaction (tonic immobility) were compared in two non-beak-trimmed hybrids (1726 birds), a medium-heavy brown (LB) and a light white Leghorn (LSL), kept in three housing systems: a three-tiered “Marielund aviary,” a traditional floor system, or conventional three-hen cages from 20-80 wk of age. LB hens showed mortality rates of 21-27% in both floor systems, mainly due to bacterial infection through pecking at the naked skin, while mortality reached on 7% in cages. The LSL showed moderate mortality (6-10%) regardless of system. Due to corresponding amounts of feather pecking, there were 10% increases in feed intake due to poor feather insulation of the body. The proportion of cracked and dirty eggs was lower in the tradition floor system than in cages for LSL birds; the proportion of misplaced eggs was similar in the aviary and the traditional system for LSL, but higher for LB in the aviary. Birds had more bumble foot, keel bone deviation, and inferior hygiene of feet and plumage but less hyperkeratosis in the floor systems than in cages. Tonic immobility duration in birds did not differ between systems, but the LSL needed fewer induction repetitions than the LB. The non-beak-trimmed LB apparently experiences social disturbance leading to pecking when kept in large groups, i.e., non-cage systems. There may be little difference in health between birds in an aviary system and a traditional floor system.