Sexing Chicken Eggs by Scent
Fertilized chicken eggs can be sexed by “sniffing” volatile chemicals emitted through the shell, according to new work by researchers at the University of California, Davis, and Sensit Ventures Inc., a startup company in Davis. The work is published May 22 in PLOS ONE.
The study shows that it is feasible to sort eggs by sex, early in incubation, based on volatile organic chemicals, said Professor Cristina Davis, associate vice chancellor for interdisciplinary research and strategic initiatives at UC Davis and co-author on the paper.
Hatcheries for laying hens sort chicks by sex a day after hatching, with male chicks being culled immediately. If hatcheries could instead identify the sex of an egg early in incubation, billions of male eggs could be humanely diverted to other uses, reducing waste and environmental impact. Some European countries have already banned culling of male chicks or plan to phase it out.
Technology already on the market depends either on sampling the egg through a tiny hole in the shell, or imaging through the shell. Imaging technology is more accurate with older eggs.
The UC Davis/Sensit approach relies on detecting volatile organic compounds given off by the developing embryo that diffuse through the shell. The first step was to find out if there is a reliably detectable difference in the chemicals given off by male and female embryos.
Davis’ lab at the UC Davis Department of Mechanical and Aerospace Engineering has developed sensing chip technology that can be used to collect and analyze organic chemicals in the air. The patented technology has been licensed by Sensit, which aims to commercialize it for a range of applications including agriculture and medicine.