BEHAVIOR, HEALTH AND INTEGUMENT OF 4 HYBRIDS OF LAYING HENS IN MODIFIED AND CONVENTIONAL CAGES

1. In 2 trials the health and behaviour of a total of 3552 caged layin g hens of 4 hybrids, Dekalb XL, Lohmann Selected Leghorn (LSL) and Sha ver 288 in trial 1 and ISA Brown and LSL in trial 2, were studied. The cage designs were Get-away cages (GA) with 15 hens per cage, a specia l version of the 'Edinburgh modified cage' called 'Modified and enrich ed cage' (ME) with 4 ISA or 5 Leghorn hens per cage, conventional meta l cages with 4 hens per cage without (GO) and with a perch (PC) and co nventional plastic cages (PL) with three hens per cage. GA and ME incl uded nests, perches and sandbaths. 2. In the first trial two nest mode ls were used, artificial turf and welded wire floor. In the second tri al both nest models were used in GA,while all nests in ME were equippe d with artificial turf. In the second trial there were 4 sandbath trea tments in ME; no sandbath, sandbath (25 x 50 cm) first opened at 16 we eks of age, sandbath first opened at 26 weeks and double size sandbath (50 x 50 cm) first opened at 16 weeks. Hens in GA were allowed access to the sandbaths from 26 weeks. 3. At 35 and 55 weeks the best plumag e condition (feather cover) was found in PL and GA but plumage conditi on in ME was not significantly inferior than in GA. Hens in GA had the dirtiest plumage and most bumble foot but no toe pad hyperkeratosis. Some toe pad hyperkeratosis occurred in the other systems. Most keel b one lesions were found in systems with perches. The highest mortality was registered in GA. Hens in systems with perches, sandbaths and nest s had increased strength of humerus at slaughter. 4. More eggs were la id in nests with artificial turf than in welded wire floor nests. LSL hens laid larger proportions of eggs in the nests (94% and 92% in the two trials) than the other hybrids. Less than 1% of the eggs in ME and 2% in GA were laid in the sandbaths. 5. The use of perches in ME and PC was approximately 30% in the day time. At night the use was 93% in ME and 89% in PC in trial 1 and 96% in ME and 81% in PC in trial 2. 6. Hens in ME with the double sized sandbath both visited the sandbath a nd performed dust bathing behaviour most, followed by hens in GA, hens in ME with access to the bath from 16 weeks and last, hens in ME with access to the bath from 26 weeks. 7. It is concluded that enrichments of laying cages are used by the hens to a large extent if properly co nstructed and managed, implying an increased behavioural repertoire of the hens compared with conventional cages. With perches at only one l evel and with smaller groups of birds, ME provided better hygiene and inspection properties than GA.