Black soldier fly larvae meal shows promise in broiler diets

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A new broiler nutrition study in Veterinary Sciences adds fresh evidence that black soldier fly larvae meal may be able to replace part of soybean meal without compromising production outcomes. The researchers tested graded replacement levels in Ross 708 broilers and assessed not just growth, but also carcass traits, meat quality, and blood biochemistry, framing the work around a practical question for poultry nutrition: how far can alternative proteins go before performance or health starts to slip? (mdpi.com)

That question has been building for years. Soybean meal is still a cornerstone of broiler formulation, but it carries cost, supply-chain, and sustainability concerns that have pushed nutritionists to look harder at insect proteins. Black soldier fly larvae have drawn particular interest because they offer a strong amino acid profile and can be produced through bioconversion systems. At the same time, the literature has been mixed. Earlier broiler work with defatted Hermetia illucens meal found that lower inclusion levels could fit well, especially early in production, while higher levels were associated with weaker feed efficiency and some unfavorable intestinal morphology findings. Other insect-meal studies have also shown that “safe inclusion” does not necessarily mean “no biological effect”: in one large broiler trial, 2% to 4% full-fat H. illucens or Tenebrio molitor meal did not change growth, feed conversion, mortality, or overall carcass quality, but insect-fed birds had higher breast yield, some meat-quality shifts such as lower breast pH and higher cooking loss in the HI4 group, dose-related thigh fat deposition, higher total and HDL cholesterol in TM-fed birds, and shorter ileal length with TM. (link.springer.com)

In the new study, 160 ten-day-old Ross 708 chicks were assigned to four diets in which black soldier fly larvae meal replaced soybean meal at 0%, 20%, 40%, or 60% on a 100% equivalent basis. According to the article summary, the team evaluated birds through starter, grower, and finisher periods and tracked growth performance, carcass characteristics, meat quality, and blood biochemical responses. The topline takeaway from the publication is that black soldier fly larvae meal showed promise as a soybean meal substitute under the tested conditions, without major harm to the measured production or health indicators. (mdpi.com)

The broader research context helps explain why that matters, and why caution is still warranted. A 2025 broiler study published in Metabolites reported that 5% black soldier fly larvae meal improved performance under an intestinal challenge model, while also increasing cecal short-chain fatty acids and lowering interleukin-6 expression, suggesting possible gut health benefits beyond simple protein replacement. But other published work has warned that inclusion level is critical: one broiler study found 10% inclusion workable, whereas 15% was associated with impaired feed efficiency and shorter villi with deeper crypts. Researchers in that paper argued that variability across trials may reflect differences in insect life stage, rearing substrate, defatting, and the production phase in which the ingredient is fed. (pubmed.ncbi.nlm.nih.gov)

There is also a useful reminder from low-soybean-meal research that replacing soybean meal is not automatically benign, even before a specific alternative ingredient is considered. In one broiler study, a 10% reduction in soybean meal increased mortality and feed intake during days 22 to 42, reduced ether extract availability, and shifted cecal microbiota toward greater Campylobacterota and Helicobacter abundance. Adding 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 and downregulated a duodenal glucose transporter gene. In practical terms, that study suggests the nutritional and microbial consequences of “less soybean meal” can be meaningful, and that any substitute has to be judged on more than crude protein alone.

Adjacent animal work also supports the idea that insect ingredients may have value beyond simple nutrient replacement, though species differences matter. In post-weaning piglets, daily live Tenebrio molitor larvae improved early feed efficiency and growth, reduced diarrhea and respiratory disorders, and helped a lower-protein diet perform comparably to a standard-protein control, without adverse effects on digestibility or serum metabolic markers by day 42. That does not translate directly to broilers, but it adds to the broader livestock picture that insect-based feeds may influence resilience, palatability, and health as well as formulation economics.

Industry and scientific commentary has echoed that same point. The Poultry Science Association’s interpretive summary on related black soldier fly oil research noted potential production and health benefits, but also flagged blood chemistry changes at higher substitution levels. The association also highlighted a regulatory reality that has shaped adoption: ingredient approval depends not just on the insect species, but on how it is produced and for which species it is intended. More recent trade reporting indicates black soldier fly ingredients are now approved in the U.S. for poultry, swine, select aquaculture species, and pet food, signaling a more mature regulatory environment than in the early phase of insect-feed research. (poultryscience.org)

Why it matters: For veterinarians working with poultry integrators, nutrition teams, or mixed animal clients, the practical takeaway is that insect meal is moving from novelty toward a more credible formulation tool. That doesn’t mean it’s plug-and-play. Health and performance outcomes appear highly dependent on formulation precision, inclusion rate, ingredient consistency, and processing quality. If black soldier fly meal is used to offset soybean meal, veterinary oversight may be most valuable in watching for subtle effects on feed conversion, gut integrity, blood chemistry, litter quality, and downstream carcass outcomes, especially when diets are reformulated aggressively or ingredients come from new suppliers. It is also worth remembering that diet changes can affect product quality in ways that do not show up in average daily gain alone; broader broiler nutrition work with non-insect additives, including phytogenic compounds such as Stevia rebaudiana extract, has shown measurable shifts in sensory traits, physicochemical meat characteristics, and storage-related quality markers. (link.springer.com)

What to watch: The next phase is likely to center on standardization and scale: more head-to-head trials, clearer nutrient specifications, economic comparisons with soybean meal, and closer scrutiny of how substrate sourcing and processing affect digestibility and bird health. For clinicians and advisors, the key question isn’t whether black soldier fly larvae can work in broilers, but under exactly which commercial conditions they work best. Future studies will also need to clarify whether insect ingredients are being used mainly as protein replacements, as functional gut-health tools, or as both, and how those roles interact with meat-quality outcomes and low-soy formulation strategies. (link.springer.com)