Worldwide, 6 billion male chicks are killed directly after hatching during egg production each year because they can neither lay eggs nor provide enough meat.

Respeggt’s solution to stop chick culling is the so-called in-ovo sexing technology. In-ovo translates as “inside the egg” in Latin. In-ovo sexing is an innovative technology that allows hatcheries to identify the gender of the hatching egg early on in the incubation process, i.e., before the chick has hatched.

How does the Respeggt technology work in detail?

The Respeggt technology is our key to success. To uphold our promise of “Free of Chick Culling”, we have invested significant time and resources in developing a groundbreaking method for inovo sexing.

The patented Respeggt technology employs cutting-edge innovation to distinguish between male and female eggs before hatching. By accurately identifying and separating male eggs from the process, we can ensure that male chicks are no longer subject to culling, making our egg production process more humane and ethical.

A set of Respeggt technology consists of 3 modules:

On around day nine of incubation, the hatching eggs are removed from the incubator. The Circuit uses
a laser to create a tiny hole of 0.3 mm (0.01 in) in the shell of all fertilized hatching eggs. A minimal amount of allantoic fluid is then extracted from the hatching eggs and placed into an external marker.

The hatching eggs are unharmed due to the non-invasive procedure used to extract the fluid, meaning that the inner part of the hatching egg is not affected. After the fluid is extracted, the minuscule hole created by the laser is sealed with beeswax.

Using PCR analysis, the extracted liquid from the hatching eggs can now be analysed to determine whether the hatching egg is male or female. This information is then automatically sent to the Sorter.

The Sorter receives the results from the Test Station and the hatching eggs are now sorted. Male hatching eggs are processed into highquality feed and the female hatching eggs are returned to the incubator. Consequently, only female chicks will hatch on the 21st day of incubation. These will later lay table eggs that are “Free of Chick Culling”.

Respeggt in Europe

Despite in-ovo sexing technologies currently being concentrated in Europe, the technology is gaining global attention.

In-ovo sexing technology means that hatcheries no longer need to practice chick culling, thus improving animal welfare standards in the egg production chain.

Respeggt performance

Annual number of
female chicks analysed by
total installed Respeggt technology:

Average accuracy in all hatcheries:





Machine capacity

  • Analysis around day 9

  • Highest accuracy on the market (over 99%)

  • Small and flexible footprint of machine
  • Suitable for all ages of parent stock
  • Labour input per set: 3 people per shift
  • Non-invasive sampling
  • Compatible with in-ovo vaccination
  • Throughput: 1 hatching egg per second per set
  • Suitable for all hatching eggs, white and brown

  • Low number of hatching eggs needed 

  • Suitable for all setter trays

  • Fits all hatchery sizes thanks to modular system.

Studies on pain perception

The Respeggt technology makes it possible to distinguish between female and male hatching eggs on around the ninth day of incubation. In-ovo sexing technology is applied by Respeggt before day twelve of the incubation as this day marks the possible beginning of pain perception by the chick embryo.

A study by TU Munich from 2023 shows that after day 12 of incubation, different processes in the embryo, e.g., brain activity, are starting. This indicates the beginning of a possible pain perception by the embryo.

Practicing in-ovo sexing before day 12 of incubation guarantees ethical benefits and meets consumer expectations. In-ovo sexing should always be applied as early as possible.

Respeggts‘ in-ovo sexing technology is one of the earliest methods, that can be implemented and is, applied on around day 9 of the incubation (see yellow area in the graph).

Respeggt’s goal is to offer even earlier technical solutions through continued research and development.

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

By applying Respeggt technology on around day 9 of the incubation, we offer an ethical solution that is  “Free of Chick Culling“!