Merged administration data are utilized to study farms that have converted to organic beef production in Ireland, to draw lessons for future CAP scheme design. Results show the complex structure of organic farms with lower cattle age progression than in non-organic systems, suggesting leakage to conventional agriculture. There is also a flow of animals as they age from poorer land in the West to better Eastern areas that are more suitable for finishing, however the flow is less for organic farms. Additionally, there is less specialisation on organic farms as more animals are finished, so leakage is less than expected.