South Korea has lost a third of its laying-hen flocks due to outbreaks of avian influenza.
Wholesale egg prices have doubled, retail prices have increased by 30 per cent and the government has cancelled import tariffs.
About 26 million birds will have been culled by Wednesday.
This set of outbreaks began Nov. 17 and is the worst in South Korea among six since 2003.
The highly-contagious influenza has spread to all provinces including a major park in south of Seoul and a scenic wetland area in the south.
No human cases have been reported.