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Title: Influence of physical activity on tibial bone material properties in laying hens

Laying hens develop a type of osteoporosis that arises from a loss of structural bone, resulting in high incidence of fractures. In this study, a comparison of bone material properties was made for lines of hens created by divergent selection to have high and low bone strength and housed in either individual cages, with restricted mobility, or in an aviary system, with opportunity for increased mobility. Improvement of bone biomechanics in the high line hens and in aviary housing was mainly due to increased bone mass, thicker cortical bone and more medullary bone. However, bone material properties such as cortical and medullary bone mineral composition and crystallinity as well as collagen maturity did not differ between lines. However, bone material properties of birds from the different type of housing were markedly different. The cortical bone in aviary birds had a lower degree of mineralization and bone mineral was less mature and less organized than in caged birds. Here, these differences can be explained by increased bone turnover rates due to the higher physical activity of aviary birds that stimulates bone formation and bone remodeling. Multivariate statistical analyses shows that both cortical and medullary bone contribute to breaking strengthThe cortical thicknessmore » was the single most important contributor while its degree of mineralization and porosity had a smaller contribution. Lastly, bone properties had poorer correlations with mechanical properties in cage birds than in aviary birds presumably due to the greater number of structural defects of cortical bone in cage birds.« less
 [1] ;  [2] ;  [2] ;  [3] ;  [1] ;  [1] ;  [4] ;  [2]
  1. Univ. de Granada, Granada (Spain). Dept. de Mineralogia y Petrologia
  2. Univ. of Edinburgh, Scotland (United Kingdom). Roslin Inst.
  3. Univ. de Oviedo (Spain). Dept. de Geologia
  4. Ames Lab. and Iowa State Univ., Ames, IA (United States)
Publication Date:
Report Number(s):
Journal ID: ISSN 1047-8477; PII: S104784771730179X
Grant/Contract Number:
AC02-07CH11358; BB/J004316
Accepted Manuscript
Journal Name:
Journal of Structural Biology
Additional Journal Information:
Journal Volume: 201; Journal Issue: 1; Journal ID: ISSN 1047-8477
Research Org:
Ames Laboratory (AMES), Ames, IA (United States)
Sponsoring Org:
Country of Publication:
United States
59 BASIC BIOLOGICAL SCIENCES; Laying hens; Avian osteoporosis; Bone fractures; Physical activity; Bone turnover
OSTI Identifier: