Customer stories

Eggs with mussel power

open this image in new window: Frenz chickens

Free-range egg producer Frenz is solving an environmental problem and boosting the nutritional content of its eggs by feeding mussel waste to chickens.

At a glance

  • Frenz discovered that hens love mussel by-product and realised it could add essential calcium, nutrients and protein to their diet.

  • The mussel farming industry creates a lot of waste that is either buried or kicked over the side.

  • After a nearly 10-year project Frenz figured out how to get a regular supply of the waste, dry it affordably, and dispense it to the chickens.

  • With the help of Callaghan Innovation Frenz is now drying a tonne of Coromandel mussel by-product a day and testing its eggs to prove the nutritional advantage.

Frenz Eggs founder Rob Darby used to get rid of leftover mussel burley from fishing trips by giving it to his hens. The birds loved it. Then he had a lightbulb moment.

“Hens love protein. They love worms, they love slugs, they love grass and they put all those benefits into the egg,” he says.

Meanwhile the green-lipped mussel farming industry creates a lot of waste that is either buried or kicked over the side back into the ocean.

“We thought, ‘what if we can find a way to dry the mussel waste and put it into the hens’ feed?’,” Darby says.

“The environment wins because we're not putting waste back into the ocean or dumping it into a landfill. We’re giving it to the hens, converting it into a great source of energy and nutrition that goes into our eggs. We send the eggs overseas and bring back export dollars. It’s a win-win for everybody, and especially for our precious environment.”

Finding this triple-win solution wasn’t simple. It took a nearly decade-long project to figure out a financially viable way to do it without creating any waste. The biggest challenge was getting everyone on board, Darby says.

The company needed to partner with mussel farmers and establish a regular supply of the waste, get the local authorities on side, develop a way of drying the product, then determine how best to deliver it to the chickens and in what quantities.

With help from a Callaghan Innovation Project Grant and support from the agency’s Research and Technical Services team, the free-range egg producer – who first introduced free range eggs into supermarkets 30 years ago – has now developed a drying system and is processing around a tonne of Coromandel mussel by-product a day.

The next step is doing comprehensive testing of the eggs to prove the recognised nutritional benefits of the new feed and create a marketing advantage for Frenz.

Frenz eggs

“Our eggs already have up to three times the amount of Omega 3 as other eggs, and are higher in protein and have less saturated fat, because of their unlimited access to green pasture, and we’re confident we’re going to find other benefits from the mussel feed,” Darby says.

“We’re in the early stages of testing – we know feeding the mussel waste to our hens is adding to the nutritional benefits of our eggs, it’s now just a matter of doing the trials for long enough,” Darby says.

“The chickens obviously need the calcium to put around their eggs, so they'll eat the mussel, they'll eat the mussel shell, they'll eat the seaweed, the squirts, the crabs, you name it.”

Paving the way for others

Frenz has been operating since the early 1980s on the core principle of ‘healthier hens, healthier eggs’. The birds derive a lot of nutritional benefits just from being out on the dewy grass in the mornings, Darby says.

A tonne of mussel waste produces around 300 kgs of dry feed containing natural sea salt, calcium for the eggshells and an array of nutrients from the mussels which are protected because of the special drying technique.

The company is experimenting with giving the chickens different quantities, but currently adds 6-8% into their feed – so every tonne of food contains around 80 kgs of mussel product. It’s also perfecting the dryer to maximise the amount of by-product it can process each day.

Frenz uses mussels from the Coromandel but the company is conscious that mussels are farmed all over New Zealand, and the ambition is to pave the way for other producers.

“We can’t dry all the waste in New Zealand, but we hope others will catch on and realise this amazing by-product can be converted into a superfood for animals.”

Chicken feed

“We share the same philosophy as Hippocrates: food is medicine. Eating wholesome food is the basis of good health, so our ambition is to make food that delivers great nutritional benefits and contributes to people’s wellbeing.”

Callaghan Innovation has been a great help, Darby says. “We couldn’t have done this without numerous partnerships, and they were always in the background offering us good, sound scientific knowledge and expertise.

“When we sell eggs to export markets, we’re not so much selling eggs as selling New Zealand. This innovation – turning waste into a nutritional benefit – has got New Zealand written all over it.”

“Diverting waste from the landfill is a clear win for Frenz and a win for New Zealand,” says Mark Eltom, Customer Manager Food and Beverage for Callaghan Innovation.

“We’re proud to have played our part in helping Frenz by providing advice, guidance and access to co-funding to help push the project ahead.”

“Increasingly New Zealand companies are looking at utilising waste streams to recover high value compounds or to convert waste streams into a feed ingredient for animals. This type of work is being enabled by more R&D occurring around the country and by the decreasing cost of the technology required.”

Updated: 14 April 2023