Black soldier fly meal shows promise as partial soy replacement

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Black soldier fly larvae meal is getting another look as a soybean meal substitute in broiler diets, with a newly published Veterinary Sciences study reporting that partial replacement can support broiler performance and health outcomes, even if higher inclusion levels may be harder to carry without tradeoffs. The study, by Ahmed A. A. Abdel-Wareth and colleagues, tested 0%, 20%, 40%, and 60% soybean meal replacement in Ross 708 broilers and evaluated growth, carcass traits, meat quality, and blood biochemistry. (mdpi.com)

The backdrop is familiar to anyone in poultry nutrition: soybean meal remains a cornerstone protein source, but cost volatility, land-use concerns, and supply-chain pressures keep pushing the industry to evaluate alternatives. Black soldier fly larvae have drawn sustained interest because they can convert byproducts into protein and fat, and because their amino acid profile can be workable in poultry diets. Prior research from the University of Georgia found dried black soldier fly larvae could be incorporated at 6% to 12% in broiler starter diets without compromising body weight gain, while also potentially sparing some corn and soybean meal use. (caes.uga.edu)

Still, the newer paper lands in a literature base that has become more nuanced. A recent meta-analysis in Animal Production Science concluded that black soldier fly larvae meal appears safe in poultry diets up to about 10% inclusion, particularly in shorter feeding periods of 35 days or less. Other MDPI-published broiler studies have reported broadly positive or neutral effects on performance and gut health at lower inclusion levels, but have also cited evidence that high-percentage replacement of soybean meal with full-fat black soldier fly meal can hurt growth performance and carcass quality. One useful comparison comes from an Animals study of 1,750 Ross 308 broilers fed 2% or 4% full-fat Hermetia illucens or Tenebrio molitor meal: growth, feed intake, feed conversion, and mortality were unchanged, breast yield increased versus controls, and overall carcass quality remained acceptable, although the higher H. illucens diet lowered breast pH and increased cooking loss, while T. molitor altered serum cholesterol fractions and shortened ileal length. In other words, the industry conversation has shifted from “can it work?” to “how much, in what form, and under what formulation constraints?” (publish.csiro.au)

That formulation question is important because black soldier fly ingredients are not nutritionally uniform. University of Georgia researchers noted that crude protein and fat content can vary substantially depending on larval age at harvest and processing conditions, and that drying temperature affected amino acid digestibility in some samples. Their work suggested earlier harvest could produce a more poultry-friendly energy profile, while processing adjustments improved digestibility. For veterinarians and poultry technical teams, that variability has direct implications for feed consistency, gut tolerance, expected performance, and interpretation of blood chemistry or carcass data across flocks. (caes.uga.edu)

It is also worth separating the effects of insect meal from the effects of simply lowering soybean meal. An Animals study in white-feathered broilers found that a diet with soybean meal reduced by 10% increased mortality and feed intake in the grower-finisher period, reduced ether extract availability, and shifted cecal microbiota toward higher Campylobacterota and Helicobacter abundance. Adding graded raffinose partly modulated some of those microbial changes and showed a tendency to reduce mortality, but it also reduced gross energy and dry matter utilization. The practical point is that “less soy” is not automatically neutral biology; the success of alternative proteins depends on what replaces soybean meal and how the whole diet is balanced.

Industry and regulatory conditions are also changing. In the U.S., AAFCO’s ingredient listings now indicate dried black soldier fly larvae are permitted for use in finfish, poultry, and swine feed, as well as some pet food categories. At the same time, FDA’s long-running MOU with AAFCO expired on October 1, 2024. FDA finalized Guidance for Industry #293 in October 2024, describing its enforcement policy for ingredients already listed in the 2024 AAFCO Official Publication, and finalized Guidance for Industry #294, the Animal Food Ingredient Consultation process, on January 6, 2025, as an interim route for firms developing new animal food ingredients. That means innovation is still moving forward, but the regulatory path is more explicitly FDA-centered than it was a few years ago. (fda.gov)

Why it matters: For veterinary professionals advising broiler operations, this study is useful less as a green light for wholesale soy replacement and more as a reminder that insect meal is becoming a serious formulation variable. Moderate inclusion may help diversify protein sourcing and support sustainability goals, but success will likely depend on ingredient standardization, amino acid balancing, energy correction, and close monitoring of flock performance and health markers. It also raises practical questions around substrate sourcing, contaminant control, and supply reliability, especially as more feed companies explore insect-derived inputs. FDA notes that animal food ingredients still need an appropriate legal marketing pathway, and contaminant oversight remains part of the safety framework. (fda.gov)

The broader animal-feeding literature also suggests insect ingredients may have species-specific thresholds and benefits. In flathead grey mullet, partially defatted black soldier fly meal did not depress growth overall, but the best gut outcomes were seen at the 10% inclusion level; higher levels were associated with worse intestinal condition and spleen changes, pointing to a threshold effect rather than an unlimited substitution opportunity. In post-weaning piglets, daily live Tenebrio molitor larvae supplementation improved early feed efficiency, growth, and health indicators, including lower diarrhea and respiratory problems, while helping lower-protein diets perform more like standard-protein controls. Those studies do not translate directly to broilers, but they reinforce the same commercial message: insect-derived feeds may offer functional upside, yet inclusion rate, product form, and species context matter.

Expert commentary tied specifically to this paper was limited in public sources, but the broader industry reaction has been consistent: insect meal is promising, especially as a sustainability tool, yet economics and consistency remain the gating issues. Trade coverage and sector reports continue to frame black soldier fly as a plausible partial soy replacement rather than a universal substitute, particularly in monogastrics where digestibility and carcass outcomes are tightly watched. That aligns with the current study’s message: black soldier fly larvae meal looks most compelling when used strategically, not aggressively. (poultryworld.net)

What to watch: The next developments to follow are commercial-scale broiler trials, clearer cost comparisons versus soybean meal, and more data on how different black soldier fly products, including full-fat, defatted, and oil fractions, perform across production stages. It will also be worth watching whether insect ingredients are positioned only as protein substitutes or more broadly as functional feed tools, similar to how phytogenic additives such as stevia extract are being studied for meat-quality effects in yellow-feathered broilers. On the policy side, watch how companies use FDA’s Animal Food Ingredient Consultation pathway and whether additional insect-derived ingredient definitions or use expansions emerge in U.S. feed regulation. (fda.gov)