title: Changes in bone fragility in laying hens.
abstract: An experiment was conducted with Hy-Line W36 hens to determine the influence of age on tibia ash and breaking strength of hens kept in cages and floor pens. Breaking strength progressively decreased from 20 to 32 weeks of age for hens kept in cages and floor pens. However, the decrease was greater with hens kept in cages. Tibia ash progressively increased from 20 to 32 weeks of age; there was no difference after 23 weeks of age between cage and floor groups. Twenty hens were moved from cages to floor and 20 were moved from the floor to cages at 26 weeks of age. Tibia breaking strength did not significantly change for those moved from cages to floor and decreased for those moved from floor to cages. The difference between the two groups was not statistically significant at 32 weeks of age.
mesh_terms: D000375:Aging; D000818:Animals; D001842:Bone and Bones / Q000502:physiology*; D002645:Chickens / Q000502:physiology*; D005260:Female; D013718:Tensile Strength; D013977:Tibia / Q000502:physiology