International team seeks to improve understanding of factors contributing to strength of important bone in laying hens. A project to understand bone health in laying hens aims to support their health and welfare, and inform breeding selection as industry moves towards non-caged systems. Outcomes from the US$3m international study will inform the selection of hens suited to egg production, whose breastbones are vulnerable to fractures, especially in non-caged birds. The collaboration led by Roslin scientists aims to develop a process of directly assessing the health of chicken’s keel bone, or sternum. Additionally, researchers will seek to better understand how nutrition can be optimised in caged and non-caged hens, and how the timing of maturity in hens, when they start to lay, affects subsequent bone quality. The five-year study is funded by the Foundation for Food & Agriculture Research via the US Department of Agriculture. Bone imaging Research into the keel bone builds on previous work by the same Roslin team, which developed a digital X-ray procedure for assessing keel bone density by imaging the legs of hens. Researchers hope to further develop this work to establish a speedy, efficient, practicable method to measure quality in the keel bone directly and to apply artificial intelligence to automate imaging and analysis. A practical way to measure bone density in the keel bone could also help reduce the number of animals needed for research into nutritional and management aids for bone health. Researchers will also investigate possible dietary approaches that might allow hens time to develop strong bones before they reach maturity and begin to lay eggs, which will help to reduce the risk of keel bone fractures in extensively housed laying hens. The team will seek to determine whether the genetic basis of keel bone quality can be assessed in the same way for caged or non-caged hens, or whether each environment needs to be considered independently. Researchers from the Roslin Institute will work in collaboration with the Swedish University of Agricultural Sciences, University of Guelph, University of Alberta, University of Granada and with commercial partners Lohmann Breeding and Hyline. Keel bone damage is a particular problem as non-cage systems are in increasing use across the world. This project seeks to enable genetic selection directly for the keel bone itself, as well as novel nutritional approaches and the influence of the timing of when hens start to lay eggs on their bone quality. Professor Ian DunnRoslin Institute ** The Roslin Institute receives strategic investment funding from the Biotechnology and Biological Sciences Research Council and it is part of the University of Edinburgh’s Royal (Dick) School of Veterinary Studies. **