A common question when starting an insect farm is: what exactly can insects eat?
Species like Black Soldier Flies (BSF) and Mealworms thrive on a variety of organic materials, from food waste to agricultural by-products. These materials, known as feedstock, provide the essential nutrients needed for their growth and development.
However, not all feedstock is equal. Factors such as nutritional composition, processing requirements, and species-specific dietary needs play a crucial role in optimising insect farming efficiency.
This guide explores the fundamentals of feedstock and insect nutrition, helping you make informed decisions to improve sustainability and maximise yields.
What is Feedstock?
Many assume that insects can efficiently consume raw organic waste as-is, but that’s not entirely true. While they can break down various materials over time, their small mouthparts limit how quickly they can process large or unrefined waste.
To improve digestibility and maximise efficiency, raw organic materials must be processed into a more suitable form—known as feedstock—which serves as their primary food source.
A well-balanced, nutrient-rich feedstock enhances larval feeding behaviour, accelerates growth rates, and improves the quality of by-products.
Common feedstocks include:
- Pre-consumer food waste (dairy, grains, bakery waste, vegetable scraps, and food factory waste)
- Agricultural byproducts (fruit and vegetable scraps, spent grains, husks, and oilseed meal)
- Retail de-aged food (as long as it does not contain animal byproducts)
Sourcing Feedstock: Key Considerations
Selecting the right feedstock is critical for maintaining insect health, optimising bioconversion efficiency, and ensuring the long-term viability of an insect farming operation. Several factors must be considered when sourcing feedstock to ensure consistency, sustainability, and regulatory compliance.
Regulatory Compliance & Legal Considerations
Feedstock sourcing is subject to local and international regulations, dictating which organic materials can be used.
- In regions such as the UK, animal byproducts (ABPs) are restricted, requiring insect farms to use only plant-based waste streams.
- Compliance with food safety and biosecurity regulations is essential to prevent contamination and ensure consumer confidence in insect-derived products.
- Understanding and adhering to legal frameworks helps mitigate risks, avoid penalties, and establish a sustainable operation.
Nutritional Quality & Consistency
- Feedstock should provide a balanced composition of proteins, carbohydrates, fats, and essential micronutrients to support optimal larval growth and metabolism.
- Nutritional consistency is vital—fluctuations in moisture content or nutrient levels can impact insect development, bioconversion rates, and the quality of final products.
- Even if two feedstocks appear similar, variations in processing methods, source materials, or storage conditions can alter their nutritional value, requiring continuous quality assessment.
- Testing and analysing feedstock regularly can help maintain a stable nutrient profile, reducing inefficiencies and ensuring predictable results.
Availability, Cost-Effectiveness & Supply Chain Stability
- Feedstock should be sourced locally whenever possible to minimise transportation costs and reduce the carbon footprint of the operation.
- Costs should remain stable and predictable to maintain profitability, as fluctuating feedstock prices can create financial uncertainty.
- Establishing a reliable and diversified supplier network mitigates the risk of shortages due to seasonal variations or supply chain disruptions.
- Long-term contracts with waste providers, food manufacturers, and agricultural producers can help secure a steady, high-quality feedstock supply.
Feedstock Processing: Why it Matters
Once a suitable feedstock is sourced, proper processing is essential for optimising its use. Since insects feed and live within their food, both nutritional and physical properties must be considered.
Particle Size & Consistency
- Small mouthparts make it difficult for insects to consume large food particles.
- Grinding, shredding, or mashing feedstock into a porridge-like consistency improves feeding efficiency.
- The optimal particle size is typically 1-3mm, allowing for easier consumption and digestion.
Moisture & Density Control
- Moisture content affects digestibility and movement within the feed.
- Excess moisture can lead to mould growth and fermentation, reducing feed quality.
- A balanced viscosity ensures larvae can efficiently move through and consume the feed.
Energy Efficiency in Processing
- Processing methods should be cost-effective and energy-efficient.
- The goal is to maximise waste conversion without excessive input costs.
Feedstock Formulations
Just like livestock, poultry and other farmed animals, insects have specific dietary requirements that directly impact their growth, metabolism, and overall productivity. Well-optimised feedstock formulations ensure efficient nutrient absorption, improve bioconversion rates, and enhance the quality of the final insect-derived products, such as protein and frass.
Macronutrient Composition & Role in Growth
A balanced macronutrient profile is essential to support healthy larval development, energy metabolism, and biomass accumulation.
- Protein – Fundamental for larval growth and development, with higher protein content enhancing body mass and enzymatic activity.
- Carbohydrates – Provide a primary energy source, influencing both larval size and metabolic efficiency.
- Fats – Support energy storage and play a role in cell membrane integrity but should be moderated to prevent excessive lipid accumulation that could slow metabolism.
- Fibre – Aids digestion and gut health but should be carefully balanced to avoid impeding nutrient absorption.
Micronutrient Balance for Optimised Development
Beyond macronutrients, micronutrients play a crucial role in larval physiology, exoskeleton formation, and metabolic efficiency.
- Calcium & Phosphorus – Essential for structural development, particularly in species that rely on mineralised exoskeletons.
- Vitamins & Minerals – Support key physiological processes, including immune function, enzymatic reactions, and overall metabolic regulation.
- Amino Acids – The building blocks of proteins, required for tissue growth, enzyme function, and cellular repair.
Feedstock Formulation Trials & Continuous Optimisation
The optimal feedstock formulation depends on species-specific dietary needs and the intended end-product (e.g., protein meal, frass fertiliser). Continuous evaluation and refinement are necessary to maximise efficiency and ensure consistent yields.
- Feedstock trials – Regular testing of different formulations helps determine the most effective nutrient profiles for bioconversion.
- Nutrient balance adjustments – Ongoing analysis allows for fine-tuning based on growth performance, waste conversion rates, and production targets.
- Quality control – Ensuring consistency in feedstock composition prevents fluctuations in larval growth and biomass yield.
The Impact of Feedstock on Bioconversion
Bioconversion refers to the process by which insects break down organic materials and convert them into biomass, frass, and other valuable byproducts. The quality and composition of feedstock play a critical role in determining how efficiently this process occurs.
Bioconversion Efficiency & Nutrient Utilisation
The nutrient profile of feedstock directly influences the rate at which larvae convert organic waste into biomass.
A well-balanced feedstock with the right mix of proteins, carbohydrates, and fats enhances metabolic efficiency, maximising the conversion of waste into high-value insect biomass. Conversely, nutrient imbalances or inconsistent feedstock composition can lead to slower bioconversion rates and reduced yields.
Larval Growth & Biomass Yield
Bioconversion is most effective when larvae have access to high-quality, easily digestible feedstock. Poor-quality feedstock with excessive fibre, imbalanced nutrients, or contaminants can slow growth and reduce biomass accumulation. In contrast, nutrient-dense and well-processed feedstock optimises growth rates, ensuring high larval survival and productivity.
Frass Composition & Waste Valorisation
Frass, the organic byproduct of insect digestion, serves as a valuable biofertiliser. The composition of frass is directly influenced by the feedstock, affecting its nitrogen, phosphorus, and potassium content. A well-formulated feedstock not only maximises protein and biomass yield but also enhances the quality of frass, making it a more marketable and effective soil amendment.
Challenges and Best Practices
Effective feedstock management is crucial for maintaining optimal insect growth rates, bioconversion efficiency, and end-product quality. However, several challenges must be addressed to ensure consistency and sustainability in insect farming operations.
Common Challenges in Feedstock Sourcing & Formulation
- Feedstock inconsistencies – Variability in supply, composition, and nutrient density can disrupt insect growth and productivity, requiring continuous monitoring and adjustment.
- Nutrient imbalances – Excess fats, carbohydrates, or inadequate protein levels can slow development, reduce biomass yield, and negatively affect bioconversion efficiency.
- Regulatory restrictions – Legal frameworks vary across regions, with strict guidelines on permissible feedstock materials, particularly regarding animal byproducts. Non-compliance can lead to operational setbacks.
- Supply chain disruptions – Seasonal availability and fluctuations in organic waste streams can affect feedstock consistency, making long-term planning challenging.
Best Practices for Feedstock Quality & Efficiency
- Work with nutritionists – Collaborating with specialists ensures that feedstock formulations meet the specific dietary requirements of farmed insects, enhancing overall productivity.
- Conduct regular feedstock analysis – Routine testing of moisture levels, macronutrient composition, and contaminants helps maintain consistency and optimise feeding efficiency.
- Establish stable supply chains – Partnering with reliable waste providers and implementing contingency plans can mitigate fluctuations in feedstock availability.
- Maintain detailed records – Tracking the impact of different formulations on growth rates, bioconversion efficiency, and final product quality allows for continuous optimisation and better decision-making.
- Ensure regulatory compliance – Staying informed about local feedstock regulations helps avoid legal complications and ensures the sustainability of the farming operation.
Final Thoughts
Successful insect farming relies heavily on the quality, consistency, and sustainability of feedstock. From sourcing and processing to formulation and bioconversion, each step plays a crucial role in maximising growth rates, optimising nutrient conversion, and ensuring high-quality insect-derived products.
Careful selection of feedstock—balancing regulatory compliance, nutritional quality, and cost-effectiveness—helps create a stable and efficient farming system. Proper processing techniques improve digestibility and feeding efficiency, while optimised formulations ensure larvae receive the right macronutrient and micronutrient balance for sustainable growth.
By implementing best practices in feedstock management, insect farmers can enhance productivity, reduce operational costs, and contribute to a more circular, waste-reducing agricultural system. As the industry continues to expand, staying informed about feedstock innovations and refining sourcing strategies will be key to long-term success.