Production performance and proportion of nest eggs in layer hybrids housed in different designs of furnished cages.

The aim of the study was to compare use of nests, production performance, and egg quality in 4 designs of furnished cages (FC) housing 8 (T8), 10 (T10), 20 (T20), or 40 (T40) layers. The FC housing 8 and 10 hens were commonly used in commercial egg production in Sweden, whereas the cages housing 20 and 40 hens constituted new designs, at present not allowed in Sweden. The FC also differed in design and location of litter facilities. The study comprised 2 full production cycles (20-72 wk of age). Trial 1 included 588 Hy-Line White W98 and 460 Hy-Line Brown layers, and trial 2 used 572 Lohmann Selected Leghorn and 588 Lohmann Brown layers. In accordance with Swedish prohibition, beak treatment was not conducted. In both trials production parameters and mortality were considered normal and levels were unaffected by cage design. Deaths attributable to cannibalistic pecking were rare. Overall, exterior egg quality was superior in T8 compared with T20 and T40, whereas T10 generated intermediate results. Genotype differences were found in production performance, exterior egg quality, and use of nests. In T8 and T10 at least 95% of the eggs were laid in nest whereas in T20 and T40 a considerable percentage of eggs were laid on the litter mat, constituting the litter facility in those cage models. Additional lighting of litter mats (trial 2) had no effect on layers' choice of site for egg laying. Dividing T40 cages in 2 identical cage halves by a rear partition with pop holes had no effect on any of the traits measured. In conclusion, housing larger groups of non-beak-treated hens together in FC is possible, with acceptable levels of production and mortality, provided that cannibalism does not develop. The inferior egg quality in T20 and T40, likely caused by the large proportions of misplaced eggs, needs to be considered in the further development of those cage designs.