Bugs as grub wipes waste

Waste-not the mantra of emerging maggot industry as larvae convert to protein


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Circular agriculture is the buzz word among a group of bug breeders intent on minimising waste while maximising protein.

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James Sackl's Melbourne-based company Karma is developing a method of constant and consistent larvae production suitable for chook feed.

James Sackl's Melbourne-based company Karma is developing a method of constant and consistent larvae production suitable for chook feed.

Imagine a farm where breeders are flies and weaners, the maggots, end up as feed for chickens, pigs and even humans.

Twenty years ago the idea that black soldier fly could help feed the world from its own left-over refuse was a concept in its infancy. In the past decade the process has become real and investment is following.

The European Union has relaxed regulations around how fly larvae can be used in food production. Meanwhile, in Australia, laws already permit this fledgling industry to supply a portion of rations for aquaculture, pork and chicken production.

Bugs as grub is a notion considered disgusting only to wealthy westerners, says Olympia Yarger, chief executive officer of the Insect Protein Association of Australia.

Asia has dined on critters for millennia while today in Kenya black soldier fly larvae are cleaning latrines and will later feed chickens which will satisfy humans. That 10 year project is showing that you don't need to be squeamish. Even so, laws in Australia prohibit larvae fed on faeces to be fed to livestock, despite the fact cold blooded insects do not pass on viral or bacterial disease.

Ms Yarger, an old wool classer, says she started as a maggot farmer and has come full circle, with her own company Goterra, based in Canberra, processing five tonnes of waste a day to produce protein. The company is ready to launch its first onsite trials of a robotic modular unit suited for on-farm use.

“Our policy is we don’t say no to waste," she says. Beef bones and chicken wings are fair game, so are biobags. Too much plastic is no good but plastics, fibres and metals can be sifted out at the end with forks and magnets.

While putrified waste is perfect for feeding breeders, the weaners must be fed on clean, green left-overs, of which many consumers bid for - especially in a drought.  Instead of fighting for the molasses and chaff, or the spent brewers’ grains Ms Yarger says she looks “further down the food chain” to grape marc, for example, which feed a new generation of black soldier fly larvae which will themselves end up as feed and oil.

“Where does this all fit into the agriculture ecosystem?” she asks. "In fact, farmers tend to look at how best they can add value. After all there is  not much you can do with waste, other than burn it or bury it,” she says. “Turning it into protein makes sense." 

In Australia, like elsewhere , the native black soldier fly is the most viable species to breed, and they can live in dark, stinky boxes at 75-80 per cent humidity around 28-30C. 

“It’s not everyone’s cup of tea..yet” says James Sackl, whose Melbourne-based company Karma is developing industrially scaleable maggot farms, robotically controlled, with the intention of establishing Australia’s first mega-scale waste-to-nutrient facility.

“Consumers and businesses are opting for the sustainable option where possible,” he says. “We are at the centre of a circular agriculture movement with a process powered by the black soldier fly.”

Karma will produce up to 5-10t/week of live larvae within the next 12 months. Current customers include organic chicken producers, zoos, fish bait suppliers and as an ingredient in aquaculture pellets.

Mr Sackl is particularly proud of the bugs’ role in retaining phosphorous in its faeces, or "frass".

“We are nearing a period known as peak phosphorous . Inadvertently, we realised that when this industry scales, it could have a tremendous impact on the recapture of phosphorus and the re-introduction of it into our soils” he said. Frass is a terrific addition to soils, Karma intends to enhance the frass even further by processing it into biochar.

At the moment, maggots as livestock feed is a concept accepted by aquaculture while pork producers have been generally behind the idea, provided it competes on cost and performance with grain. The poultry industry is less enthusiastic, which is a shame says  Dr Isabelle Ruhnke, senior lecturer in animal science at the University of New England, Armidale.

Her recent research presented laying hens with a choice of their regular enhanced rations or black soldier fly larvae, squished of their oil in a process known as "de-fatting" and freeze dried for storage. The results were clear - laying hens replaced up to 16% of their diet with the larvae because it was rich in energy.

“A little bit like wanting ice-cream,” explained Dr Ruhnke. “The hens accepted black soldier fly larvae very well,” she said.

Compared to soy meal at 48 per cent protein and 2pc fat, BSF larvae, de-fatted, provide 55 to 60pc protein at 8pc fat. Maggots straight out of the paddock comprise 30pc fat which is too much if a farmer wants to produce eggs.

Dave Cadogan, nutritionist with the company Feedworks, says rendering of larvae, removing the fat, not only prolongs the product’s shelf life,  but the oil that is pressed out is a medium chain fatty acid similar to coconut oil and palm oil. It serves as a gut tonic by neutralising pathogenic bacteria and has much wider potential in the human consumption market.

There is evidence to say that eggshells are thinner after 12 weeks on a trial diet of fly larvae but this is not from a lack of nutrition in the larvae, but rather the lack of mineral and vitamin supplements which would have been digested had the hens chose formulated feed over bugs.

For the same reason egg yolks from hens on BSF larvae were a pale yellow compared to those from hens on regular feed because those rations included colouring to modify the look, in the way that farmed salmon appears orange. Current research funded by the Poultry CRC is investigating the impact of Black Soldier Fly larvae on chicken meat quality.

In contrast, ruminants have trouble with the fatty larvae, too high in protein with the result that excess nitrogen converts to ammonia gas which is toxic. Of course feeding cattle with maggots reared on meat is a no-no but even larvae reared on vegetable waste are unlikely to ever be feed to ruminants in Australia, according to Goterra’s Ms Yarger.

“This is a new industry and understandably people have a lot of questions,” she said. “But the industry has matured. It is more credible. For instance we understand different waste as insect feed substrates, like pig effluent, better than we did before. We know how it works. On the other hand we, as an industry, need to demonstrate we can manage concerns about food and health safety.”

“We are on the threshold," she says, "of something big.” 

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