title: Effects of strontium on bone strength, density, volume, and microarchitecture in laying hens.
abstract: Strontium has been reported to have beneficial effects on bone. Treatment of laying hens, which are susceptible to osteoporosis and bone fracture, with strontium increased DXA measurements of BMD and BMC and microCT measurements of bone volume and microarchitecture and improved the mechanical performance of whole bone, but had no effect on the estimated material properties of the bone tissue.
  
  
  BACKGROUND
  Strontium (Sr) has been reported to dissociate bone remodeling and have positive influences on bone formation. We supplemented the diet of laying hens, which are susceptible to osteoporosis and bone fracture, with Sr to study the capacity of the element to improve bone mechanical integrity and resistance to fracture.
  
  
  METHODS
  Increasing dosages of Sr (0, 3000, 4500, and 6000 ppm) were fed to 196 13-week-old pullets for 11 months. BMD and BMC, as measured by conventional and DXA methods, microarchitectural parameters derived from microCT, and structural and material properties as determined by three-point bending test, were studied. Calcium (Ca), phosphorus (P), and Sr levels in plasma and bone, as well as egg output, shell quality, and composition, were assessed.
  
  
  RESULTS
  Sr concentrations in plasma and bone increased in a dose-dependent manner without affecting Ca and P. Treatment with Sr increased BMD and BMC as measured by DXA, increased cortical and medullary bone volume, trabecular thickness, number, and surface, and improved whole bone ultimate load, but had no effect on the estimated material properties of diaphyseal bone. Sr also increased the ash content of eggshells and did not affect egg output and shell quality.
  
  
  CONCLUSIONS
  Sr supplementation induced large positive effects on bone density, volume, and microarchitecture as measured by radiographic methods. Sr treatment also improved the structural strength of diaphyseal bone but had no effect on the estimated material properties of the bone tissue.
authors.affiliation: Department of Nutritional Sciences, Pennsylvania State University, University Park, Pennsylvania, USA.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Shahnazari
authors.forename: Neil A
authors.initials: NA
authors.lastname: Sharkey
authors.forename: Gary J
authors.initials: GJ
authors.lastname: Fosmire
authors.forename: Roland M
authors.initials: RM
authors.lastname: Leach
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D015519:Bone Density / Q000187:drug effects*; D050071:Bone Density Conservation Agents / Q000494:pharmacology; D002645:Chickens; D003720:Densitometry; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D005260:Female; D050723:Fractures, Bone / Q000517:prevention & control; D010024:Osteoporosis / Q000188:drug therapy; D013314:Stress, Mechanical; D013324:Strontium / Q000494:pharmacology*; D013718:Tensile Strength
chemical_list: D050071:Bone Density Conservation Agents; D013324:Strontium