Abstract. The objective of the study was to assess bone breaking strength, keel bone status and egg quality parameters of Lohmann Silver (LS) and Lohmann Tradition (LT) layers housed in small group systems (SG) and furnished cages (FC) in comparison to an aviary system. At the end of the 3rd, 6th, 9th and 11th laying month, approximately 40 hens were randomly chosen from each housing system and slaughtered (478 hens in total). Humerus and tibia strengths were analysed using a three-point-bending machine. Keel bone status was evaluated on a scale from 1 (severe) to 4 (no deformity). Shell breaking strength was measured every four weeks, totalling 4,887 eggs. Statistical analyses were performed using the MIXED procedure of SAS. Humerus and tibia strengths of LS layers housed in SG were significantly higher compared to LS hens kept in FC. Bone breaking strengths of humerus and tibia in LS and LT layers were highest in the aviary system and the differences to the other housing systems were significant. No significant differences in tibia and humerus bone breaking strengths were found between SG and FC for LT hens. Keel bone status was not significantly influenced by housing system or laying strain. For both hybrids, shell breaking strength was significantly lower in SG compared to FC and aviary system. The results showed that SG systems can significantly enhance bone breaking strength for LS layers in comparison to hens kept in FC. The lower shell breaking strength of eggs in SG might slightly impair economic aspects.
In the 3rd, 6th, 9th and 12th laying month, foot pad health, plumage condition, integument and claw length were evaluated in 432 Lohmann Silver laying hens kept in three different housing systems: a small aviary housing system (Eurovent 625a-EU, EV) with different perch levels, a furnished cage system (Aviplus, AP) and an aviary (Voliere Natura, AV). Foot health was scored for hyperkeratosis and lesions on a scale from 1 (normal) to 5 or 4 (severe). Plumage condition was assessed with scores from 1 (worst) to 4 (best) for different body regions. Integument was assessed for lesions and claw length of the middle toe was measured. Mild foot pad hyperkeratosis was the most frequent finding in hens of all housing systems. Sole pad hyperkeratosis was less frequent in AP and occurred more often in EV and AV. Significantly more often hyperkeratosis in the region between toe and claw was observed in AP. Toe pad lesions and lesions between toe and claw were scored lowest in AV and highest in AP. An aggravation of plumage in the course of the laying period was observed in all hens. Hens showed a significantly better total plumage condition in AP compared to EV. Within housing system, group size had a significant influence on plumage condition. Plumage was better in smaller groups. Lesions of the integument were rarely detected. Claws were significantly shortest in AP, longer in AV and longest in EV. Perch design in EV was not significant for all traits except for comp lesions.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.