Leading judges in Germany have backed the practice of gassing or crushing to death millions of male chicks in the egg industry.

An estimated 45 million unwanted birds annually are killed this way in Germany alone, but the practice is commonplace worldwide.

Male chicks cannot lay eggs so are considered useless by egg and poultry producers.

The German Federal Administrative Court gave the green light to the practice in a case involving a hatchery that specialises in egg-laying hens.

But the court said a company’s economic interests don’t constitute a “sensible reason” under animal protection laws for killing the birds, and that techniques to determine chicks’ gender in the egg – so that males are not hatched – should soon be available.

Trio of eagles raise chicks as a team Show all 10 1 /10 Trio of eagles raise chicks as a team Trio of eagles raise chicks as a team An unconventional family of bald eagles comprised of two males and one female have been filmed raising eaglets together AP Trio of eagles raise chicks as a team The trio were spotted living together along the Mississippi River near Fulton, Illinois AP Trio of eagles raise chicks as a team The two males are sharing their second partner after their original female mate was killed by another eagle Stewards of the Upper Mississippi River Refuge Trio of eagles raise chicks as a team Stewards of the Upper Mississippi River Refuge have named the males Valor I and Valor II and the female Starr Stewards of the Upper Mississippi River Refuge Trio of eagles raise chicks as a team A webcam set up by the stewards in 2011 is allowing animal enthusiasts around the world watch live footage of the trio raising their chicks Stewards of the Upper Mississippi River Refuge Trio of eagles raise chicks as a team The original trio formed in 2013 when Valor I's previous partner chose Valor II as a new mate Stewards of the Upper Mississippi River Refuge Trio of eagles raise chicks as a team However Valor I hung around for the rest of the breeding season and, after their mate was killed in 2017, the pair courted new female Starr together later the same year Stewards of the Upper Mississippi River Refuge Trio of eagles raise chicks as a team Three eggs have been laid by Starr hatched this spring Stewards of the Upper Mississippi River Refuge Trio of eagles raise chicks as a team A screengrab from the livestream of the eagles Stewards of the Upper Mississippi River Refuge Trio of eagles raise chicks as a team The eagles in 2016, before Starr replaced now dead prior mate Stewards of the Upper Mississippi River Refuge

Soon after hatching, egg producers globally separate out the billions of male baby birds to be ground up or gassed.

The RSPCA says most – if not all – male chicks in the UK are killed using inert gas, which can take up to two minutes to kill them, but maceration is also allowed.

British group Animal Aid has estimated 30 million day-old male chicks are disposed of every year in the UK, while worldwide estimates reach 2.5 billion.

Tor Bailey, of Animal Aid, said the court’s decision was a lost opportunity.

“This is hugely disappointing, as the technology exists, but once again economics wins out over welfare. We have no need to use and abuse animals in food production,” she said.

In 2016, the German parliament voted against a Green Party bill calling for a ban on killing male chicks, as members decided the economy would suffer if industrial hatcheries moved abroad.

Julia Klöckner, the agriculture minister, has described the practice as “ethically unacceptable” and called for a ban.

But the court in Leipzig has upheld it until new technology on sex determination in eggs is introduced.

A German company called Seleggt started to sell the first “no kill” eggs last year after developing a non-invasive way to determine the sex of chicken embryos. Only females are allowed to hatch.