Interesting Discussion- Why Feed Spent Grain to Black Soldier Fly Larvae To Produce Feed When It Can Be Fed Directly to Fish?

I had an interesting discussion recently with a fish nutritionist about the use of black soldier fly larvae (BSF) as a potential fishmeal replacement for the aquaculture industry. The conversation was very engaging and led us down an interesting path of debate and enlightenment about this topic. I thought I would share with you some highlights and offer you a chance to reflect and hopefully comment on the topic- so please feel free to respond to the post.

My initial point to this individual with regards to the BSF industry was focused on the "good" the system presents to the environment. The idea that BSF can be used to recycle food waste and produce protein. Doing so, keeps these wastes from entering landfills and potentially polluting the environment. The system appears to have many strengths as it takes something of potentially no value and converts it to products of value. Of course, BSF represent a key product as it has been shown as a potential fishmeal replace for diets of fish grown in aquaculture. 

What I learned (informed) is the use of the term "replacement" is not appropriate as the nutritional makeup of the BSF is not equal to fishmeal. This did not come as as surprise to me. But, I did learn I need to me more careful with the language used to describe BSF products and their value. I am still not sure what the appropriate term should be - but I will definitely be more careful with describing the value of the product. 

​As a side note, I also would like to point out BSF fed brewery waste are higher in some of the key components needed in fish diets (e.g., higher protein and select amino acids such as methionine), while having lower fiber content. Furthermore, where brewery waste can spoil if not used quickly- BSFL produced from the system can be stored. Furthermore, BSF can take heterogenous materials and create a homogenous product where nutrients are concentrated.

The second learning point from this discussion is spent brewery grains can be fed directly to some fish or other aquaculture species grown in culture (I included a few references for your review). These materials can be a partial "substitute" for select ingredients.  The key word here is "some" as it cannot be generalized across all fish species. I do not say this as something that is new to me but rather as a reminder to be more cognizant about the language I use and to avoid generalizations. Be specific, do not generalize, and be concise and clear with the language used when talking with others.

A Few Papers to Read:
Incorporation of brewery waste in supplementary feed and its impact on growth in some carps

Pito brewery waste as an alternative protein source to fishmeal in feeds for Tilapia busumana

New developments in aquatic feed ingredients, and potential of enzyme supplements

Third, education is critical for creating opportunities for the BSF industry. While many of us recognize the value of the BSF to the world, many are still not aware of the potential of this system and what it means to the various commodities (e.g., aquaculture, poultry, or agriculture in general as related to compost). So, we all should take the time to start the discussion with learning more about what others know before launching into benefits of the system. Patience and education are vital to gain acceptance and advance the science.

Fourth, we still have a lot of work to do.  I really enjoyed the discussion and learned a lot from it. Most importantly, I recognize even more the need for conducting research, building partnerships, and expanding the BSF industry beyond entomology.  Experts from other fields bring so much to the table and should be engaged and invited to join the effort for deciphering all aspects BSF. 

I thought I would share this experience with you as I came to the realization that such interactions are important for everyone to be aware of (talking amongst ourselves simply creates an echo chamber of agreement)- and that the industry still has a ways to go towards acceptance. I welcome the challenge and look forward to working with those accepting, or not, of the capabilities of the BSF industry to impact the world in a very positive way.

Author

Jeffery K. Tomberlin, PhD, Excited about Outreach
Director, EVO Conversion Systems
​Twitter: @FliesFacility