Insects as animal feed

To this end, samples and experts regularly commute between the laboratory in Gießen and the Hanau Industrial Park, where Evonik has pooled its animal feed expertise. “The right amino acid profile lets us exploit more of the leftover material for the larvae as well as reduce costs and thus produce a competitive protein,” says Häußner. This is the only way that the insect feed idea can make insect farming into a successful business.

The market is promising, and insect startups are currently getting hundreds of millions in funding every year from investors. The global market for insect proteins is forecast to grow dramatically between now and 2030: by 5,000 percent to half a million tons of proteins per year. It will still have room for growth even then, because almost five million tons of fish meal and more than 380 million tons of soybeans are produced every year. Overfishing, deforestation, and huge climate-related effects are the result. “Just like our amino acids, insect proteins could help to feed the world’s growing population much more sustainably,” says Häußner.

The larvae begin their lives in net-covered “love cages,” where thousands upon thousands of flies mate if the conditions are right. The incidence of the light, the temperature, and the humidity all have to be the same as those in the flies’ home, the tropics. In Gießen, the love cages are located in a hothouse; they fill a well-heated hall at Heinrich Katz’s company in Baruth.

After mating, every female fly lays around 500 eggs, from which larvae hatch two days later and immediately begin to eat. If put on the right substrate, they will grow to 15,000 times their original size within two weeks. As a result, the larvae easily reach a “dressed weight” of 300 milligrams.

A small percentage of the larvae are allowed to pupate so that they turn into flies that can create the next generation. Most are used for production. In the laboratory, the larvae are flash-frozen, after which they are ground into a powder that can be dosed directly into animal feed or broken down into its constituent elements: protein, fat, and chitin. In addition to being used in feed, proteins are also in demand by the chemical and pharmaceutical industries. The same is true of the chitin from the carapace, which can be used to make biodegradable polymers. The fats, meanwhile, can be used by industry to make biodiesel or plastics.

Even the muck from the “maggot stable” is useful. Known as “frass” (a term derived from a German word for “feed”), this contains excrement, cast-off skin and the remains of feed. “Experiments in India have shown that this material can double rice yields when it is used as a fertilizer,” reports Vilcinskas.

So, is everything set for a big revolution in animal nutrition? Not quite, because the feeding of larvae to pigs and chickens has only been permitted in the EU since this summer and only to a limited extent. The ban was a relic from the BSE crisis of the 1980s and ’90s. The disease had been caused by the use of processed animal cadavers in cattle feed. After that incident, farmers were no longer permitted to use animal-based proteins in feed. The only exception was the use of fish meal in aquacultures. For decades, experts tried to get the ban lifted because pigs, chickens, and fish like to eat insects when they are outdoors. “Insect protein contains many essential amino acids,” says Häußner. “In addition, the soldier fly produces around 50 antimicrobial peptides, which strengthen the animals’ immune systems and might thus reduce the use of antibiotics.”

The researchers are correspondingly pleased that the ban has been partially lifted. However, there is still one obstacle in Europe: Livestock may not be fed waste and the black soldier fly is defined by law as livestock. The situation is different in other countries. The Kenyan startup Insectipro, for example, feeds larvae with 20 to 30 tons of waste per day from the capital city of Nairobi. It sells the larvae to pig and chicken farmers in the surrounding region. Similar projects are also under way in Asia. In some places, the BSFs also consume manure, slurry, and human feces.

The researchers in Gießen are striking out in new directions and trying to exploit food channels that might be approved by the EU. For example, the INFeed project also involves a sweets manufacturer that is looking for ways to use cocoa bean shells. The researchers have also garnered interest in Indonesia, where huge amounts of material from the fruiting heads is left over at palm oil mills. “To date, the fibrous plant material has been either used to generate energy for the mill or simply burned out on the fields,” says Rühl. The researchers in Gießen have developed a fermentation process that makes this material edible for the BSF larvae. These larvae would be an almost climate-neutral feedstuff for fish and prawn farmers in Southeast Asia. The frass would be spread on the fields. “The antimicrobial peptides in the feed might also make the shrimps more resistant to disease and reduce the need for antibiotics.”

The researchers in Gießen want to demonstrate this benefit, so a shrimp farm is to be built next to the Fraunhofer Institute this year. Located far from the sea, this farm will contain big tanks, where black tiger prawns will eat sustainably produced larvae – the insatiable waste consumers from the dark boxes.

Photos: Robert Eikelpoth (5), Oliver Soulas / Fraunhofer

Illustration: Oriana Fenwick / Kombinatrotweiss on the basis of an original photograph by Stefan Eisenburger