Graphic footage seemingly showing day-old male chicks being shredded in Melbourne egg hatcheries has renewed animal rights activists’ calls for an end to the legal practice.

Animal Liberation and Aussie Farms released footage on Tuesday that they say shows male chicks being pushed through a maceration machine.

Many male chicks are destroyed when they are born since they do not produce eggs.

“We’ve known about this process for a long time but it’s been very highly guarded by the industry; nobody’s been able to capture it here in Australia until now,” Aussie Farms director Chris Felforce said.

“I think most people would be absolutely horrified to learn that this is what they’re paying for when they buy eggs, even those with ostensibly higher-welfare labels like ‘free range’.”

The practice is legal in Australia.

“Quick maceration” is categorised as an acceptable form of humane destruction of chicks in Australia, according to the model code of practice for the welfare of domestic poultry.

“Culled or surplus hatchlings awaiting disposal must be treated as humanely as those intended for retention or sale,” the code says.

“They must be destroyed humanely by a recommended method such as carbon dioxide gassing or quick maceration and thoroughly inspected to ensure that all are dead.”

The video was allegedly shot in a Melbourne hatchery called Specialised Breeders Australia. Comment has been sought from SBA.

Germany will introduce technology by the end of 2016 that will identify the sex of chicken embryos before they are hatched. The US has committed to stop culling chicks within four years.