Three million egg-laying hens killed each year: Redundant egg layers can become food

The reason for the current practice of destroying the birds instead of slaughtering them for human consumption is that the latter is not profitable enough for producers. The slaughter of laying hens would require a restructuring of the automated process currently used for chickens, which would be both resource intensive and create additional costs for the poultry slaughterhouses. This is something the researchers want to address.

"An ever-increasing global population and a rising demand for food will make it unsustainable not to find a profitable way of exploiting the resources which three million laying hens represent," says Project Manager Ana Carvajal at SINTEF. According to Carvajal, the interest in hens has increased in recent years. For example, the military has participated in a pilot project in which the birds were used as food. "However, it's been difficult in practice to find good applications for the hens in terms of new food products that meet consumer demands. For one thing, it takes longer to cook a hen than a chicken," she says.

Nothing goes to waste

Currently, the vast majority of laying hens are gassed and then destroyed. Most then end up as components in concrete bonding agents. Barely five per cent are slaughtered as a raw material for large-scale catering facilities such as in the military. The classic Norwegian "hen" fricassée hasn't entirely disappeared from dinner tables, so a couple of Norwegian producers are still sending their hens for slaughter.

But the birds also contain valuable oils and proteins. "Part of the project will be investigating food products that can be produced from hens currently being slaughtered," says Carvajal. "Another aspect will involve applying a variety of technologies such as enzymatic hydrolysis in order to extract materials from the birds for use as food or animal feed. Enzymatic hydrolysis uses enzymes to break down the raw materials into oils and valuable proteins. Globally, proteins are currently in short supply," she emphasises.

The researchers aim to conduct a bio-economic exploitation of the birds -- meaning that nothing will go to waste. Any residual material remaining after the hens have been exploited for food or animal feed will be used for products such as soil improvement agents.

Marine industry technologies

Carvajal and her colleagues are working very closely with the aquaculture and fisheries industries, which have been working for many years to find profitable ways of stepping-up the exploitation of marine-derived waste raw materials.

This has also been a key preoccupation of the agricultural sector. "Expertise and technologies developed for the exploitation of marine-derived waste can be applied to generate profits from redundant egg layers," says Carvajal.

Organisations participating in the project include Nortura and Norilia, the egg producers' network Jådåren, the Norwegian University of Life Sciences at Ås, Bioforsk, and the animal feed research division at Felleskjøpet. In other words, a highly skilled alliance which is currently focusing on the afterlife of egg-laying hens.

"The first thing we do is to find out exactly what these birds can be used for," says Carvajal. "After that we can consider what technologies can be applied to make the process profitable. For example, we can envisage the development of mobile slaughterhouses which can be transported to a farm facility so that the hens can be destroyed, humanely and in compliance with regulations, without them having to be moved to another location," she says. The project is being funded with NOK 3.25 million from the Regional Research Fund for Mid-Norway and NOK 1 million from the participating organisations.