Better Bones

  • Ian Dunn (Creator)
  • Colin Simpson (Data Manager)
  • Pete Wilson (Creator)
  • Heather McCormack (Creator)
  • Robert Fleming (Creator)
  • Björn Andersson (Creator)
  • Matthias SCHMUTZ (Creator)
  • Alejandro Rodriguez-Navarro (Creator)



Data used in the analysis presented in the publication 'Lack of genetic correlation between bone quality and egg number in the laying hen suggests increased egg production may not be responsible for reduction in bone quality '.


The physiological adaptations for egg laying make hens susceptible to bone fractures and keel bone damage. Longer periods of egg laying in modern breeds could bring a greater risk of poor bone quality and it is frequently stated that selection for increased egg production is a cause. However, the historical literature does not support this hypothesis. To test the hypothesis of a correlation between egg production and bone quality, breaking strength and density, genetic correlations were estimated in White Leghorn and Rhode Island Red breeds. Additionally the correlation of the cortical and medullary bone material chemical properties with bone quality were estimated. The aim is to improve bone quality with appropriately targeted measurement of key traits.
Bone quality traits in both breeds had moderate heritability (0.19-0.59) with the exception of the keel bone where heritability was not different from zero. There was no evidence for a genetic or phenotypic relationship between post peak egg production and bone quality. In the White Leghorn there was a significant negative correlation between age at first egg and bone quality (-0.7 to -0.4). Thermogravimetric measurements of tibial medullary bone mineralisation were significantly heritable (0.18-0.41) as were the genetic correlations with tibia breaking strength and density (0.6-0.9).
This study has identified that onset of puberty and well-mineralised medullary bone, a specialised adaptation for egg laying, may be an important factor in determining the quality of the skeleton later in egg production. These are areas where genetic but also environment and management factors can have positive outcomes for the overall quality of the skeleton of laying hens. The lack of correlation between post peak egg production and bone quality suggests increased egg production does not necessarily adversely affect bone quality. Will appear in Genetics Selection Evolution 2020.

Data Citation

Dunn, I et al. "Better Bones" [dataset] (2020) Edinburgh DataVault.
Date made available2020
PublisherEdinburgh DataVault
Date of data production1 Nov 2015 - 1 Nov 2018

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