It is not clear how long it will take for Česká drůbež to restore its flock so it can restart egg production. If the company can obtain mature hens chickens, production could be restarted relatively fast, Dlouhá said. Currently, though, there is a shortage of mature hens in Europe due to bird flu. If Česká drůbež buys new-born chicks, it will take about 20 weeks before they start laying, according to Dlouhá.