There are approximately 7.5 million laying hens in Sweden, according to the Swedish Board of Agriculture. Turnover in the population is more than 5.5 million each year. The eggs laid contain as many male chickens (cockrels) as females, but since the cockrels cannot lay eggs and are unsuitable for use as food, they are killed and the bodies destroyed. A research team at LiU’s Department of Physics, Chemistry and Biology (IFM) has developed a method to solve the problem.
“The eggs can be sorted right from the start, when they’ve just been laid. The eggs destined to become cockerels can be taken out to be used in food production, or even eaten as eggs”, says Anita Lloyd Spetz, professor emerita at IFM.
Analysing the gases
The researchers can now determine whether the egg is destined to become a cockerel or a hen by analysing the gases emitted from it. Research into sexing eggs is being carried out in several places, and the methods used differ.“This is important work – being able to save cockerels in this way, so that they don’t have to be killed – it solves a large ethical problem. Many groups have made considerable progress, but no other group uses gas sensors as we do”, says Professor Anita Lloyd Spetz. According to the researchers, the advantages of this method are that it can be done at an early stage and that it is relatively cheap.
Jan Ybrahim was still a student when the project started a year ago. His degree project investigated the gases emitted by the eggs and showed that the composition of the gases differed between those destined to become cockerels and those destined to become hens. The research team was able to analyse the gases at different temperatures using silicon carbide sensors, developed at the IFM. In his subsequent research, Jan Ybrahim has modelled the values measured and derived an equation that can distinguish cockerels from hens with 85% accuracy. “Indeed – that’s what we can achieve at the moment. And there are many reasons to believe that we can reach a better figure”, says Jan Ybrahim, who holds a master’s degree in engineering biology.
When will this be commercially available?
“It’s difficult to say, but we’ve come a long way in six months. What remains is to translate this into a commercial method such that it makes economic sense”, says Anita Lloyd Spetz.
What is the goal of the research?
“I hope that sometime in the future, and I don’t know when, that the unnecessary killing of cockerels will end. Quite simply – the eggs can be used and the total amount of suffering reduced. That’s the principal goal for me”, says Jan Ybrahim.
The research has received financial support from the Agtech 2030 initiative.