‘Sniffing’ chicken eggs could help determine sex before hatching

This happens for two reasons—male chickens in the egg production industry cannot lay eggs themselves and are also unsuitable for meat production. This is because “layer hens,” which are bred for laying eggs, are different from the kinds of chickens that are raised for their meat.

But if hatcheries could identify the sex of an egg early in the incubation of the fertilised egg, this could prevent billions of male chicks being killed every year. Instead, the fertilised eggs could be diverted to other uses. Some countries like Germany have already banned the industrial culling of male chicks.

‘Sniffing’ the egg

There is already technology on the market that can sample the eggs through a tiny hole in the shell or through imaging, according to UC Davis. The new approach works by detecting the volatile organic compounds that are given off by the developing embryo and diffused through the shell.

To develop the approach, the researchers adapted suction cups that are used in the industrial handling of eggs to pull in air from the eggs without opening them. These air samples were then analysed at a lab using gas chromatography/mass spectrometry using a sensing chip technology they had developed.

The researchers adapted suction cups used in the industrial handling of eggs to “sniff” them. (Image credit: UC Davis)

The sex of the eggs was then confirmed using DNA analysis and they found that this method could be used to identify between male and female embryos in eggs that were incubated for 8 days with an accuracy of 80 per cent.

The results of the research have been published in an article in the peer-reviewed journal PLOS ONE.