The SFBN Angle: While most industrial BSF plants focus on pre-consumer food waste, the real "System Boundary" challenge lies in low-value, high-pathogen urban waste streams. Carlos A. López Manzano’s research at Concordia University reveals a critical trade-off for operators: Sterilization vs. Performance. For the industry, this is the difference between a high-CAPEX "clean" facility and a high-efficiency "bio-active" system.

Key Discovery: The 50:50 Sweet Spot

The lab results are clear: BSF larvae can survive on 100% goose feces, but they don't thrive. However, by moving to a 50:50 blend with a standard substrate, you maintain high survival while successfully processing a "zero-cost" (or potentially "tip-fee") feedstock.

SubstrateSurvival/GrowthStrategic Value
100% Goose FecesLow/SlowProof of concept; hard to scale alone.
50:50 BlendHigh/StableThe Industrial Entry Point.
Control (Standard)MaximumThe benchmark for ROI.

The "Microbiome Signal": Why Sterilization Might Be Slowing You Down

One of the most profound insights from the Khelifa Lab is the impact of autoclaving.

  • The Assumption: Sterilizing feces makes it "safer" and easier to digest.
  • The Reality: Autoclaving actually reduced larval performance in some treatments.
  • The Insight: The native microbes in the feces aren't just "hitchhikers"—they are likely aiding in the breakdown of complex fibers. For an operator, this suggests that expensive heat-pretreatment might actually be counter-productive to growth rates.
Why this matters for your CAPEX: If the native microbiome is doing the heavy lifting, the need for intensive pre-processing equipment (like industrial autoclaves) might be lower than we thought—provided safety protocols for the final product are met.

Beyond the Larvae: The Frass-to-Duckweed Loop

The research didn't stop at the insect. The team tested the resulting frass on duckweed growth, a common aquatic plant often used as animal feed.

  • Finding: Frass derived from goose-feces diets supported robust duckweed growth.
  • The Circular Opportunity: This points to a "Closed Loop" urban model:
    1. Collect urban waste (Geese feces).
    2. Convert to BSF Protein + High-value Frass.
    3. Use Frass to grow Duckweed (a secondary revenue stream or feed supplement).

Implementation Guide for Pilots

If you are looking to trial avian waste in your facility:

  1. Don't go 100%: Start with a 50:50 mix to buffer the nutritional gaps and stabilize the colony.
  2. Monitor Sanitation: Goose feces carry pathogens of public health concern. While BSF are known to reduce Salmonella and E. coli, rigorous testing is non-negotiable for regulatory compliance.
  3. Test the "Native Load": Before investing in sterilization equipment, run a side-by-side trial of "raw" vs. "treated" waste to see if the microbiome is assisting your growth rates.

Credits & Acknowledgments

This research was conducted by Carlos A. López Manzano (Master’s student) under the supervision of Professor Rassim Khelifa at the Khelifa’s Lab, Department of Biology, Concordia University.

Source: "From waste to resources: Converting Canada goose feces into protein and plant fertilizer using the black soldier fly” BSFCON 2025.