"We are expecting a legal challenge, but would stand by our argument that it is unnecessary killing, and as such, outlawed by animal welfare laws," a spokeswomen for the NRW environment ministry told The Local.
Announcing the edict on Thursday state environment and consumer minister Johannes Remmel said: “This practice is very cruel. It makes creatures a by-product of the agricultural industry.”
The chicks are killed because they are not deemed suitable for meat production and cannot lay eggs.
But in a year's time, farmers in the state will have to feed the male chicks until they are suitable for slaughter, the ministry spokeswoman said.
The decision was sparked by and backs up a case against a small hatchery in Münster where the prosecutor said killing the male chicks broke animal protection laws as there was no reasonable grounds to do so.
European laws allow the chicks to be shredded or gassed, but a spokeswoman for the consumer affairs ministry said the state prosecutor believed this was not legitimate.