The SELEGGT process

The SELEGGT process is a way to prevent chick culling. The scientific approach of endocrinological (hormone-based) gender identification in the hatching egg has been extensively automated with the SELEGGT process and is already being used in practice today.

During the process, the nine days incubated hatching eggs are removed from the incubator and checked for fertilisation based on sensors. A precision laser opens the eggshell by creating a small hole with a diameter of approx. 0.3mm in the eggshell of all fertilised hatching eggs. A small amount of allantoic fluid is then extracted. The allantoic fluid of female hatching eggs contains estrone sulphate, a female gender hormone. The fluid is extracted non-invasively by means of a precise, electronically controlled suction process. Consequently, it has no negative consequences for the hatching egg, as the inside of the hatching egg remains untouched and unharmed.

The fluid sample is now applied to a patented marker outside the hatching egg. The marker reacts to the estrone sulphate with a colour change. The hatching eggs can now be distinguished and sorted into male and female gender according to the colour change. This way, it is possible to process the male hatching eggs into high-quality feed, while the female hatching eggs are returned to the incubator.

Immediately after the allantoic liquid has been extracted, the hole in the eggshell is sealed with beeswax to minimise the risk of contamination of the inside of the hatching egg. The advantage of beeswax is that, as a natural material, it is permitted as an ingredient in feed and can be used without any problems when the male hatching eggs are further processed into feed.

On the 21st day of hatching, only female chicks hatch, which then become respeggt laying hens that lay respeggt eggs. Further information for consumers can be found at

The SELEGGT process in brief


By loading the video, you agree to YouTube's privacy policy.
Learn more

Load video

Studies on pain perception

The SELEGGT process makes it possible to distinguish between female and male hatching eggs on the 9th day of incubation. We are aware that scientists debate the exact moment at which a chicken embryo is able to perceive pain. The Research Services of the German Bundestag has stated that the perception of pain is possible from the 15th day of incubation. The incubation days before that are evaluated differently by scientists.

We believe that this debate is important and necessary but should not prevent us from making a sectoral improvement today.

If at all, the probability of perceiving pain or other negative experiences on the 9th day of incubation is very small. In any case, the SELEGGT process should always be considered as an improvement to hatching, sorting, transporting and killing a day-old chick.

Stopping the incubation process of male hatching eggs is very fast and effective. In addition, these eggs can be used as high-quality feed and thus play an important role in the circular approach to nutrient use.

PDF: (in german): About Pain Perception of chicken embryos
(paper from the scientific service of the Bundestag)