Stories

Closing the loop: How using insects and waste as animal feed can protect the planet

Brown chickens walk around and peck at the ground on a farm

Date: January 30, 2024
Author: Ellen Dierenfeld and Madalen Howard

Over the past 25 years, we’ve witnessed a significant shift in how we approach animal-sourced food, revealing unexpected trends on our plates. Our growing global appetite for meat, milk, and eggs raises urgent concerns about agriculture's environmental impact on our planet.

In a recent WWF publication, we highlight four solutions to transform how we produce animal feed to protect people and nature:

Responsible sourcing
Regenerative agriculture
Circular ingredients
Feed Innovations

The approach aims to reduce agriculture’s negative impacts on the planet by holding unsustainable food systems accountable and acknowledging the need for scaled action. We must also point out the successful examples of sustainable systems already in place in the world.

Embracing circular ingredients

Embracing circular ingredients means adopting a smart approach that transforms the way we handle food, elevating what was once seen as waste into a higher-value ingredient by either repurposing or preventing it. The goal is to stop the unnecessary loss of resources and add value to what we have^1,2. For example, without forethought, grains leftover after brewing a vat of beer are seen as low-value waste products. But with a bit of effort that so-called waste can be transformed into a better, higher-value commodity like animal feed.

Circular systems offer environmental advantages

Circular systems aim to throw away as little as possible, find a high-quality use for waste products, use resources wisely, and cut down on how much we impact the environment. By using circular methods, we can create diets that provide proper nutrition with less land and fewer heat-trapping greenhouse gas emissions that contribute to the climate crisis. Research conducted by WWF explored multiple approaches to elevate excess food from waste into feed for egg-laying hens including:

Food waste from retail outlets fed to black soldier fly larvae, processed into meal.
Food waste from retail outlets is processed into a feed ingredient.
Bakery by-products from food manufacturing plants are fed directly to hens.

Each approach has tradeoffs and requires more research to properly implement them. However, there is evidence that these approaches can offer environmental advantages, specifically in addressing issues like deforestation and the conversion of vital ecosystems into agricultural land.

Black soldier fly larvae.

Harnessing the power of insects

Besides directly feeding excess food to livestock animals, there are also examples of using food system waste to create entirely new livestock feed production loops. Perhaps the most current innovation can be seen in the growth of the insect protein industry over recent decades—particularly black soldier fly larvae. WWF supports a pilot project in Victoria Falls, Zimbabwe that cleverly harnesses the power of this humble insect. The project uses nothing more complex than fly larvae with hearty appetites to break down excess food and/or manure. As a result, the larvae transform waste into beneficial products. The larvae can be harvested and processed as a feed ingredient, or fed intact to chickens, serving as a nutritional, inexpensive alternative to traditional livestock feed ingredients like soybean meal. Plus, larvae manure serves as an organic fertilizer!

Using insects as an ingredient in animal feed has the potential to change the industry. Black soldier fly larvae can consume food from a wide variety of sources, take up almost no land, and hold tremendous nutritional value, making them a sustainable option for feeding fish, chickens, pigs, and even pets^3,4,5. Imagine donating your dinner scraps to a farm that uses those scraps to raise fly larvae as feed for their animals and then supply you with locally raised pork, poultry, and fish!

A sustainable feed system is possible

As we navigate the complexities of increasing global demand for animal-sourced food, the path to a more sustainable and environmentally conscious food future is within our grasp. By reimagining our food system to minimize waste, efficiently use resources, and reduce environmental impact, we can create a world where what's on our plates contributes to a healthier planet. The journey toward sustainability is not just theoretical; it's happening now. WWF is at the forefront of initiatives that champion these transformative practices. Through partnerships, projects, and other ongoing efforts, we’re actively working to turn these sustainable aspirations into reality.

Together, we can shape an environmentally friendly future that goes beyond just the choices we make about what goes on our dinner plates and instead includes a successfully engineered and sustainable feed system.

Learn more about WWF’s work on food waste.

^[1]Van Zanten et al. 2019 https://www.sciencedirect.com/science/article/pii/S221191241930077X
^[2]Muscat et al. 2021 https://www.researchgate.net/profile/Abigail-Muscat/publication/353784692_Principles_drivers_and_opportunities_of_a_circular_bioeconomy/links/62b3206c1010dc02cc538b75/Principles-drivers-and-opportunities-of-a-circular-bioeconomy.pdf
^[3]McBride et al. 2020 https://files.worldwildlife.org/wwfcmsprod/files/Publication/file/2q8g6qmx4s_WWF_NoFoodIV_Waste_to_Feed_Pathways.pdf
^[4]Patterson et al. 2021 https://www.sciencedirect.com/science/article/pii/S0032579121003060
^[5]Mohan et al. 2022 https://www.sciencedirect.com/science/article/abs/pii/S0044848622002113