The world has a poop problem. A big one. By 2030, it will be a 3.7 billion-tonnes-a-year problem, and that’s just accounting for faeces produced by farmed animals. This, by any measure, is a lot of poop, particularly considering many countries already struggle to deal with it.
Much of this excess excrement can be used as crop fertiliser, but this is tricky in areas such as the Netherlands or northern Italy where there is a lot of livestock and little arable land. The alternative is to transport manure to areas where it is required. Another solution? Feed it to insects.
This is what happens in nature, so why not? Animals only use about 60 per cent of the energy and protein in animal feed, the rest of which they excrete. So where you and I might just see a steaming pile of poo, Jason Drew sees nutrients and opportunity. He is co-founder and CEO of the Insect Technology Group, a company that’s been farming Black Soldier Fly (BSF, the insect species most commonly used in animal feed) in South Africa since 2009. He thinks manure would make a great feedstock for the insects, which could then be used as animal feed. “What do people think happens in the wild? A real farmyard chicken will definitely have eaten [insect] larvae raised on poo,” he says. “The logic is there.”
In the wild, flies such as the house fly or the black soldier fly thrive on manure. It has just the right amount of nutrients and moisture and is the perfect growing medium for their larvae. In spring and summer, with warm temperatures, they’ll go from egg to adult in just a few weeks. “It’s been tested for over 150 million years,” Drew says.
That’s the theory. So what about the practice? Insect farms are commercial operations, and just like every other business, they must balance their inputs and outputs. There are three main outputs from insect farming: protein, fats and insect manure (also known as frass, which can be used as a fertiliser), with protein providing the biggest profits. Feedstock heavily impacts the final composition of the insect, especially the protein content, so insect farmers must develop feedstocks that not only achieve the highest yield, but also the optimal composition for their target market. Too high a fat content, for instance, may lead to a shorter shelf life or the need to de-fat the insect. Animal feed manufacturers will also have specific nutritional requirements and expect a consistent product.
This balancing act is what piqued Dennis Oonincx’s curiosity. A scientist at Wageningen University and Research in the Netherlands, his research on the use of insects as food and feed led him to ponder all the nutrients insects could upcycle from manure. “What I want to know is: if you have one ton of manure, how many larvae will you get? How much protein? How can you optimise the yield?” In other words, does it make sense commercially to raise insects on manure?
MultiCycle, one of the Insect Technology Group’s companies, has been experimenting with pig and chicken manure as a feedstock for several years and Drew says manure definitely works. It would most likely need to be mixed in with other feedstocks such as food waste, but this would be something for individual producers to work out (most insect farms have developed proprietary feedstocks, which can vary with the seasons to accommodate different waste streams).
Of course, manure isn’t without its drawbacks. Drew says they have had some disasters at MultiCycle, including killing all their larvae once after feeding them chicken manure contaminated with insecticides. “The chickens had been fed insecticides to avoid fly contamination on the poultry farm. We didn’t know. Now we won’t accept manure from farms that use insecticides.”
Oonincx also explains that some pathogens, such as the coccidia parasite, which is commonly found in chicken manure, are not digested by some species of insects. In such cases, insects would need to be processed before they can be used as animal feed.
Many regulators balk at the prospect of allowing manure-fed protein on their markets, especially the European Union (the United States and China are slightly more relaxed). Insects have been approved for use in pet food, poultry feed and aquafeed in Europe and North America since 2017. Their high protein content and favourable amino-acid profiles (similar to other animal proteins and better than plant-based proteins) make them desirable alternatives to environmentally-damaging proteins such as fishmeal (which is contributing to overfishing) and soy (a leading driver of deforestation in South America). But their use as animal feed has come with strict conditions, including what they can be fed (currently agricultural waste and pre-consumer waste excluding meat and fish).
The EU’s caution is understandable: ever since the BSE crisis in the 1990s, there have been stringent restrictions on what can be included in animal feed. Insects are considered livestock animals and therefore subject to the same rules.
At a recent seminar, Sabine Jülicher, director for food and feed safety and innovation at the Directorate General for Health and Food Safety of the European Commission, emphasised that health and safety was the Commission’s number one priority when it came to authorising new insect products and feedstocks on the market. The use of animal by-products in insect feedstock was still “at reflection stage,” she said at the meeting. “It’s a consideration but I have no timescale. It’s the most complex and requires the most preparation.”
The regulator isn’t the only one treading cautiously. The insect sector itself – in Europe at least – is in no hurry to allow manure as a feedstock, still working on the essential task of getting insects approved as food (the European food safety watchdog confirmed that yellow mealworm was safe for human consumption on January 13) and feed (pet food and aquafeed are already allowed; poultry and pig are expected to follow in 2021). “From a business perspective, [manure as a feedstock] is not a low-hanging fruit,” says Oonincx. “[Insect companies’] approach is: ‘Let’s put hazardous materials aside first and focus on what’s safe and get over the hurdle of acceptance first’. We need to get the whole feeding animals to animals thing done right and establish the safety and suitability of this alternative protein.”
The use of manure as a substrate does appear on the International Platform for Insects as Food and Feed EU policy roadmap on the use of insects as feed, but it is last on the list (priority is for former foodstuff including meat and fish, followed by catering waste and slaughterhouse products).
One way to bypass health and safety concerns and realise the manure revolution would be to use the insect products for non-food applications, such as pet food or industrial lubricants. But this would mean losing out on the high-end protein market of aquafeed. Pet food regulation can also be very strict, and industrial applications – cosmetics and biofuel, for example – are uncharted territory for now.
Kees Arts, CEO and founder of Protix, the largest BSF facility in the world, says it will be worth keeping an eye on these new markets but his conviction is that the real potential for insects is in the food chain. “Insects cover the entire range of nutritional applications, from protein to antioxidants, and we think we’re only just scratching the surface.” He thinks insects could be used for biostabilisation or biodegradation of manure, where insects would help break down hazardous components or reduce the initial mass, but the focus wouldn’t be so much on the larvae being harvested. “We believe there is a future for that but it’s not our mission. Our priority is bioconversion and we focus on controlled, hygienic, safe environments.”
But Oonincx thinks it would be a terrible waste not to use the larvae, hence his determination to pursue research on the topic. Regulation, he says, usually plays catch up with research and industry: legislation on the use of insects as food in Europe, for instance, is only just coming through even though insects have been on the market for the best part of a decade because of various (perfectly legal) loopholes. Drew is bullish too. “Five or six years ago, if you talked about insect protein, people looked at you as if you were very strange. Now they think it’s cool. More people know about it, and for those who already know about it, they think: ‘Manure, why not?’,” he says. “It’s a gradual process: first we fed insects spent grain [from brewers], then mixed food waste, then in ten years, everyone will think it’s absolutely normal to feed them manure. And then we’ll get to human waste.”
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