> An estimated 4-6 billion male chicks are slaughtered globally every year because they serve no economic purpose. Some are suffocated, others are fed alive into grinding or shredding machines to be processed into reptile food.

“If you can determine the sex of a hatching egg you can entirely dispense with the culling of live male chicks,” said Seleggt managing director Dr Ludger Breloh, who spearheaded the four-year programme by German supermarket Rewe Group to make its own-brand eggs more sustainable.

Breloh said his first breakthrough came when he approached scientists at the University of Leipzig where Prof Almuth Einspanier had developed a chemical marker – similar to a pregnancy test – that could detect a hormone present in high quantities in female eggs. Mixed with fluid from fertilised eggs at nine days, the marker changes blue for a male and white for a female, with a 98.5% accuracy rate.

A laser beam burns a 0.3mm-wide hole in the shell. Then, air pressure is applied to the shell exterior, pushing a drop of fluid out of the hole. The process takes one second per egg and enables fluid to be collected from eggs without touching them.

“It worked absolutely faultlessly,” said Breloh of the test phase. “Today, female hens are laying eggs in farms in Germany that have been bred without killing any male chicks.”

Article from 2018 in regard to cull-free eggs nearly a half of decade later