Chicken or chicken? Sex determination in the egg
In no other livestock, the specialization in the target of use has reached a similar level as the chicken, so the veterinarian at the Clinic for birds and reptiles. Roosters of breeds that are bred for laying eggs, find no takers and are simply superfluous. Therefore, more than 40 million male hatchlings just hatched are killed each year in Germany alone. Routine killing affects all areas of laying hens, including the bio-sector. "This is a socio-political issue, both from the point of view of animal welfare and industry," says Krautwald-Junghanns.
However, the second-use breeds that used to be widespread, in which hens and roosters are used for meat production after a certain laying performance, have become obsolete from an economic point of view - beyond organic farming. Instead of the "multi-purpose chicken", fattening lines that have already reached a slaughter weight of 30 grams after 1500 days and highly specialized laying lines are bred. When breeding laying hens, however, not only do the hens required for egg production hatch, but also roughly the same number of chickens, which are undesirable due to the lack of economic possibilities for use, from the eggs.
In the joint research project with zoologists, physicists, chemists and engineers from the University of Jena, the TU Dresden, the Frauenhofer Institute, the arxes Information Design Berlin GmbH and the Lohmann Tierzucht GmbH Cuxhaven, the Leipzig researchers are getting closer and closer to their goal, a reliable method for sex determination to develop in the unhatched hen's egg. In January / February 2011 patents were granted for two vibration spectroscopic methods. This currently most promising research status of the project, which ended at the end of June, arouses great interest in the professional world.
The research project funded by the Federal Office for Agriculture and Food (BLE) for three years with a funding amount of around one million euros in the area of "Innovation Promotion" will end in June 2011. A new application should then examine the reliability of the new methods of the project "Possibilities of In ovo sex determination in domestic chickens as an alternative to the routine killing of day-old male chicks from laying hen lines. "In further studies, we therefore want to pursue three new approaches, among other things, with regard to the possible uses of optical and vibration spectroscopic analysis methods," explains the coordinator.
For the currently preferred spectroscopic methods, a hole created in the egg shell by means of a laser serves as access for further, light-assisted analysis. However, the hatching rates from sampled eggs have so far only been tested on a small scale. "It is now important to also precisely analyze the effects of the individual examination steps on the breeding process and success, on the postnatal development of the chicks as well as the animal health and laying performance of the hens."
The Animal Welfare Act states that no animal may be killed or tortured without a reason. But the economy itself is also concerned with avoiding the killing of millions and millions of healthy chickens every year. "For me, the ethical component is in the foreground, after all, it is about living animals whose only flaw is being male," says the veterinarian. The support from the economic side is nevertheless crucial: "Many projects have always died when economic aspects were not sufficiently taken into account."
So far, there are no practical methods for sex determination in hen's eggs that would leave them as undamaged as possible. This could change in the medium term with the intended, completely new endocrinological, spectroscopic and imaging methods. "Then, ideally, unhatched eggs, from which chickens would one day hatch, could still be brought to the market," says Krautwald-Junghanns. And last but not least, that would also help to reduce the number of laying hens needed to supply the population with eggs and egg products.
Source: Leibzig [Uni]
