Differences in management between organic and conventional production in different countries, as well as differences in trait definitions and analysis models, make it difficult to generalize the results. Contrary to the Swedish results, Nauta et al.(2006b) show G×E between organic and conventional herds for production traits in first-lactation Holstein cows. Genetic correlations for longevity between other environments or countries have been shown to vary between 0.3 and unity (Haile-Mariam et al., 2008; Forabosco et al., 2009).