Free range and organic systems expose the laying hen more to unexpected events and adverse climatic conditions than barn and cage systems. In France, The Netherlands and Switzerland the requirements for a hen suitable to produce in free range and organic systems were discussed with farmers. The farmers preferred for these systems a more ‘robust’ hen, more specifically defined as a heavier hen with good eating capacity."
Benchmarking of flocks in a web-based management program in The Netherlands from layer flocks finished in 2008 – 2013 indicated that in earlier years indeed mortality among organic and to a lesser extent free range hens was higher than among barn or cage hens. Feed conversion (kg feed/kg eggs) is higher, but the gap is closing."
Improvements in management of the hens during rearing and in the layer phase in free range and organic systems seem to be important. Breeding companies take behaviour and performance in non-cage systems into account in their selection programs."
Heavier hens need a diet with a lower protein to energy ratio. From model calculations we concluded that in organic systems a heavier hen might be economically profitable, as total feed costs are lower for the heavier hen then for a hen with a lower body weight requiring a diet with a high protein content. For conventional free range hens this is not the case as then the protein content can be adapted by synthetic amino acids."
Field studies and cooperation between farmers and breeding organisations will have to show if a strain of heavier hens will be successful in the rather small organic market.