Aarhus University Seal

Scientists improve health and welfare of organic laying hens

The mortality rate among organic laying hens is twice as high as for layers from enriched cages. In an international research collaboration scientists from Aarhus University will be investigating why this is so with the hope of improving the health and welfare of laying hens and this dissatisfactory statistic.

Mortality among organic hens is twice as high as in enriched cages. A new research project seeks to rectify this problem. Photo: Janne Hansen

Despite strenuous efforts more organically reared laying hens are dying prematurely than laying hens reared in  cages. In organic flocks, the death rate is around 10 per cent, while in conventional flocks with cages it is only around 5 per cent under Danish conditions. 


Scientists from Aarhus University, University of Copenhagen and from seven other European countries will be looking into the causes of the excessively high mortality rate in organic egg production.


One of the requirements for an organic production is that the hens must have access to an outdoor area - but this also exposes the hens to the risk of parasitic and predator attacks. Scientists will study the causes of death from multiple angles. Egg producers will be interviewed, there will be systematic observations of live hens, and dead hens from a number of organic farms will be autopsied.


The causes of mortality will be examined both at flock level and for individual hens. This is in addition to identifying the management and feeding factors that affect feather-pecking, parasitic infection and the use of the outdoor area.


The studies at flock level will be based on data from more than 100 flocks in the eight countries. The large data material will give scientists a unique opportunity to identify risk factors.


Research will consist of three closely integrated projects that use the same hen flocks and carry out recordings simultaneously in the flocks.


“HealthyHens” is a project of the EU ERA-NET under Core Organic II and is carried out in collaboration with the University of Copenhagen and research environments in seven other European countries and is coordinated by ICROFS. The purpose of the project is to promote good health and welfare in the European organic egg production industry.


The project “Færre døde høns” (Fewer dead hens) is funded by Fonden for Økologisk Landbrug (Foundation for Organic Farming) and the PhD project "Promoting animal health through improved health in organic egg production" has been set up by the GSST graduate school at Aarhus University.


Scientists are interested in hearing from Danish organic egg producers who might be interested in joining the project. You can learn more by contacting PhD student Lena K. Hinrichsen, e-mail: lena.hinrichsen@agrsci.dk, telephone: +45 8715 7876 or Research Director Jan Tind Sørensen, e-mail: jantind.sorensen@agrsci.dk, telephone: +45 8715 7923, both from the Department of Animal Science


Text: Janne Hansen