Figure 1.

Prevalence of keel bone deformities (KBD) assessed at the end of the rearing period (A) and during the laying period, when hens were kept in floor pens (B) or single cages (C) of the first generation. Each bar represents the percentages of hens without deformities (Score 4; green part of the bar), with slightly deformed (Score 3; yellow part of the bar) and moderate to severe deformed keel bones (Score 2; red part of the bar), respectively. The number of examined hens within the single weeks of age is given in brackets above the bars.