Lactation can be extended to last at least 16 to 18 month by delayed rebreeding in dairy cows. An extended lactation strategy holds potential to improve dairy cow longevity and efficiency due to fewer calvings with associated health risks and fewer dry periods over an expected lifetime. In a typical Danish dairy production the lactation period will be 10 to 11 month based on early rebreeding after calving. However, rebreeding in this period is often challenging and with poor outcome in terms of pregnancy rate, and it is also not clear if early rebreeding is the optimal strategy in relation to milk production, reproduction, cow health, milk quality, environmental impact or economic outcome of the production. Results on some of these aspects from recent Danish experiments and from investigations on private Danish farms on extended lactation strategy will be presented and discussed. The feeding level and the feeding strategy imposed will affect lactation yield and persistency for the dairy cows on extended lactation strategy. An extended lactation strategy might increase the variation between cows and challenge the commonly applied TMR feeding strategy with one feed ration used for all lactating cows. Likewise, an individualised or group-based feeding strategy might be more favorable in relation to increased lactation length and the implied demand for increased lactation persistency for the extended lactation strategy to become successful. Results on individualized and live-weight based feeding strategies in relation to extended lactation performance and metabolic load of the dairy cows will be presented and discussed. Finally, extended lactation strategies will be discussed in relation to dairy cow lifetime performance and herd scenarios.