Insect farming: A novel approach for future sustainable agriculture

Insect-based proteins can replace conventional animal feed components, providing high-quality protein and fats with lower carbon footprints. This makes insect rearing an attractive circular economyfocused strategy for reducing emissions in food production and contributing to the UK’s net zero targets.

DR SARAH BUCKINGHAM, SENIOR CONSULTANT, ENVIRONMENT TEAM

Globally there are a variety of insects that are reared for human nutrition, animal feed and waste management, such as black soldier fly, mealworms, lesser mealworms, crickets, locusts, housefly and others.

In a European and UK context, the most commonly reared insect for protein production is the black soldier fly (BSF). There is growing evidence showing insect-based proteins can effectively supplement or replace conventional animal feed components by providing high-quality protein and fats with lower carbon footprints compared to soy-based feed.

Therefore, incorporating insects into agricultural and food production systems offers a sustainable alternative protein source that can potentially replace the UK’s reliance on soy imports.

Insect proteins and fats have been used in aquaculture since 2015, offering an alternative to fishmeal products and are increasingly used in pet food production to replace soy and meat-based ingredients. In 2021, the European Union permitted the use of insect processed animal proteins to be used within poultry and pig nutrition.

Insects can also contribute to waste management (bioconversion) and supply various bioactive compounds (chitin) used in agriculture, textiles, and pharmaceutical industries. This has made the incorporation of insect rearing into argi-businesses an attractive circular economy-focused strategy for reducing emissions in food production, contributing to circular economy goals and UK’s net zero targets.

So, what are some of the potential benefits to agri-businesses?

Reduced carbon footprint and environmental co-benefits: Research highlights that utilising insect-based protein in animal feed has lower greenhouse gas emissions and lower land and water demands compared to soy production. A reduction in soy production (due to decreased demand) could also lead to reductions in other negative environmental impacts associated with soy production, such as deforestation, soil degradation, destruction of wildlife habitats, and the loss of natural grasslands in some regions of the world. Utilising insects in waste management can also reduce volumes of material sent to landfill (and emissions associated with landfill).

Scalable and reliable enterprise: UK-based insect rearing provides a more reliable protein source compared to imported sources, which may be affected by geopolitical/market volatility issues and subsequent economic impacts. Due to the short life span of insects (e.g., harvest the larvae approximately 10-15 days old with the full life cycle of BSF being around 35-45 days depending on diet), insect rearing can be more readily scaled according to business needs compared to other protein sources.

Waste reduction, valorisation and circular economy: BSF can eat almost anything (organic), making them efficient bioconverters. However, if BSF products are to be utilised directly within the food chain, there are strict regulations on BSF diets, which comprise mainly pre-consumer food waste, including fruit, vegetable and grain waste as well as unprocessed former foodstuffs (dairy and egg).

Insect rearing offers a pathway to upcycle agricultural wastes into animal feed (from the insect larvae) and/or organic insect manure (frass). Zero Waste Scotland reported that both BSF and anaerobic digestion treatments of food waste provide net carbon savings. However, BSF generates approximately 10% additional carbon benefit. Insects are highly efficient at rapidly converting organic material into biomass and frass, and SRUC are investigating the potential use of frass as an alternative to synthetic fertilisers.

So, what’s next?

Insect rearing is an exciting area of emerging research, innovation and application, providing a novel pathway for valorising waste into usable products. Despite the many reported benefits, there are challenges with uptake due to potentially high initial investment (depending on the scale of operation) and difficulties in aligning insect farming standards to agri-businesses. There is also a need for further research and knowledge required, e.g. the protein production yield and quality derived from different waste streams, the consistency and standardisation of substrate, frass composition and its effect on soil/crop health, and life cycle analysis of incorporating insects into supply chains.

At SRUC, we are excited to be contributing to research and commercial development in this field by investigating the commercial viability of insect frass (and chitin) and life cycle analyses for scope 3 emissions reduction strategies in commercial supply chains.