Egg producers have been given an extra two years to phase out the use of battery cages.
Primary Industries Minister Nathan Guy said on Thursday the move is to avoid a large increase in the price of eggs.
He said an independent review found that there would have been a significant disruption in the supply and price of eggs with the earlier transition dates.
Mr Guy said farmers need more time to get resource consents and build new sheds.
Battery cages installed before the end of 1999 must now be replaced by the end of 2018. Cages installed before the end of 2001 have until the end of 2020 to be changed.
The final date of 2022 for all layer hens to be out of battery cages remains unchanged.