International Journal of Poultry Science and Farming

Black Soldier Fly Larvae Meal as a Partial Soybean Replacement in Broiler Diets: A Review of the Evidence

Solomon Tanaka¹, Jorge Park², Elin Gebremedhin³

¹ Department of Agri, Netravati Academy of Agri, Romania, ² Department of Agri, Bharathapuzha Institute of Agri, Chile, ³ Department of Agri, Achankovil Academy of Agri, Poland

Published 02 Sep 2026 Vol. 1, Article 1 10.62715/ijpsf.2026.v1.i1.pp1-7 0 accesses 0 citations

Download PDF XML HTML EPUB

0Accesses

0Citations

Abstract

Soybean meal supplies most of the protein in broiler diets worldwide, and its price, its land footprint and the dependence of many countries on imports have prompted a search for partial substitutes. Meal made from larvae of the black soldier fly, Hermetia illucens, is the insect product that has received most attention. This narrative review examines what the published literature says about replacing part of the soybean meal in broiler diets with larvae meal. It covers the composition of the meal and the reasons that composition varies, the digestibility and energy values measured in broilers, growth and feed efficiency at different inclusion levels, effects on the gut, the carcass and the meat, safety and regulation, and the economic and environmental arguments. The literature supports a cautious conclusion. Moderate inclusion in diets balanced on digestible amino acids has generally been tolerated, whereas high inclusion has more often been associated with poorer feed efficiency. The meal is variable, its crude protein is overstated by the conventional nitrogen factor, and sulphur amino acids remain limiting. The review closes with the questions that feeding trials have not yet answered, among them standardised product description and the performance of commercial flocks over complete production cycles.

Keywords: Hermetia illucens Insect meal Black soldier fly Soybean meal Broiler nutrition Alternative protein

1. Introduction

Broiler production rests on two ingredients, a cereal for energy and soybean meal for protein. The arrangement works because soybean meal is rich in lysine, consistent from one consignment to the next and well characterised in every feed formulation database. Its weaknesses lie outside nutrition. Soybeans are grown in a few exporting regions, the price moves with currency and trade policy, and expansion of the crop has been linked to land-use change. Producers in importing countries, and especially small feed mills in Africa and Asia, therefore have a standing interest in protein sources that can be produced locally.

Insects entered this discussion in earnest after the Food and Agriculture Organization published its assessment of edible insects for food and feed (van Huis et al., 2013). Among the candidate species, the black soldier fly, Hermetia illucens, has attracted the most work. Its larvae grow on a wide range of organic residues, the adult does not feed and is not regarded as a pest or a disease vector, and the prepupae leave the substrate of their own accord, which simplifies harvesting (Sheppard et al., 1994). The idea is not new. Dried larvae were being fed to chicks as early as the 1970s (Hale, 1973). What has changed is the scale of production and the number of controlled feeding trials.

This review asks a narrow question: what does the published evidence say about using larvae meal to replace part, not all, of the soybean meal in broiler diets? Partial replacement is the realistic case. Supplies of insect meal are small beside the tonnage of soybean meal that the poultry industry consumes, and nutritionists introduce an unfamiliar ingredient at low inclusion before they trust it at high.

2. Scope and Approach

The article is a narrative review of the published literature. It draws on the general reviews of insects as feed (Makkar et al., 2014; Veldkamp and Bosch, 2015; Gasco et al., 2019), on the review of black soldier fly composition by Barragan-Fonseca et al. (2017), and on primary studies of digestibility and performance in broilers and closely related poultry. No formal search protocol was applied and no pooled estimate is offered. Studies on laying hens and quail are mentioned where they help to interpret the broiler work, and larval fat is treated only briefly because the question here concerns protein.

3. Composition of Larvae Meal and Why It Varies

A formulator replacing soybean meal needs to know what is being put in its place, and for larvae meal the answer depends on how the larvae were reared and processed. Table 1 summarises the features that matter most and sets them against soybean meal.

Table 1: Features of black soldier fly larvae meal that bear on its use in place of soybean meal
Feature	Larvae meal compared with soybean meal	Consequence for formulation	Source
Crude protein	Similar or lower in full-fat meal; higher after defatting	State the degree of defatting; formulate on analysed values	Makkar et al., 2014
Nitrogen factor	Chitin nitrogen inflates protein calculated with 6.25	True protein is lower than the label suggests	Janssen et al., 2017
Amino acids	Lysine adequate; methionine and cystine limiting, as in soybean	Synthetic methionine is still required	Barragan-Fonseca et al., 2017
Fat	Far higher and very variable; rich in lauric acid	Raises dietary energy and saturated fat	Spranghers et al., 2017
Minerals	High calcium and a wide calcium to phosphorus ratio	Reduce limestone; check available phosphorus	Makkar et al., 2014
Consistency	Varies with substrate and processing	Analyse each source before use	Spranghers et al., 2017

3.1. Protein and amino acids

Full-fat larvae meal carries rather less crude protein than soybean meal on a dry matter basis, and partially or highly defatted meals carry more (Makkar et al., 2014). The figure on the label needs care, however. Part of the nitrogen in an insect is bound in chitin and other non-protein compounds, so the conventional factor of 6.25 overstates true protein. Janssen et al. (2017) proposed a factor of about 4.76 for whole larvae of the species they examined, Hermetia illucens among them. A meal that appears to match soybean meal on crude protein may therefore deliver appreciably fewer amino acids.

The amino acid pattern itself is favourable in most respects and fairly stable. When Spranghers et al. (2017) reared prepupae on four different organic substrates, the amino acid profile changed little, while fat and ash changed a great deal. Lysine, valine and the other branched chain amino acids are well supplied. The sulphur amino acids are not, which means that larvae meal shares the main limitation of soybean meal instead of correcting it (Barragan-Fonseca et al., 2017). A diet in which one replaces the other still depends on supplemental methionine to meet the requirements set out for broilers (NRC, 1994).

3.2. Fat, chitin and minerals

Fat is the most variable fraction. Its amount depends on the substrate and the stage of harvest, and its fatty acid profile is dominated by lauric acid, a saturated medium-chain fatty acid that the larva synthesises itself. The remaining fatty acids reflect the diet of the larvae: feeding fish offal, for example, enriched them in long-chain omega-3 fatty acids (St-Hilaire et al., 2007). Chitin is the structural polysaccharide of the cuticle. Estimates based on acid detergent fibre overstate it, because that fraction also contains bound amino acids (Finke, 2007), but some chitin is always present and broilers digest it poorly. The cuticle of this species is also mineralised, so the meal is rich in calcium and has a wide ratio of calcium to phosphorus.

4. Digestibility and Energy Value in Broilers

Formulating on digestible amino acids requires measured coefficients, and several groups have supplied them. De Marco et al. (2015) determined apparent nutrient digestibility, ileal amino acid digestibility and apparent metabolisable energy for a full-fat Hermetia illucens meal and a Tenebrio molitor meal in broilers, and concluded that both were useful sources of energy and digestible amino acids. Schiavone et al. (2017a) repeated the exercise for a partially defatted and a highly defatted meal and found that the two differed in energy value and in the digestibility of individual amino acids, a difference they related to processing as well as to fat content.

Two points follow for practice. One is that there is no single matrix value for larvae meal in the way there is for a soybean meal of stated protein content; each product needs its own. The other is that heat applied during drying and fat extraction can depress amino acid digestibility, as it does in any animal protein meal, so two meals with identical proximate analysis may not feed alike.

5. Growth Performance at Partial Replacement

The feeding trials are easier to read once the sources of variation between them are set out. Figure 1 groups them under the meal, the formulation and the bird. Trials differ in all three at once, which is why apparently contradictory results are common and why a single recommended inclusion level cannot be read off the literature.

Figure 1: Groups of factors that shape how broilers respond when larvae meal replaces part of the soybean meal

The broad pattern is nonetheless consistent with the reviews of Gasco et al. (2019) and Veldkamp and Bosch (2015). At low to moderate inclusion, with diets balanced for digestible amino acids and energy, growth and feed conversion have usually matched those of the soybean control. Onsongo et al. (2018), working in Kenya with meal that replaced part of both the soybean meal and the fish meal, reported no penalty in growth or carcass traits and a better economic return under local prices. In growing quail, Cullere et al. (2016) found that defatted meal could replace a share of the soybean meal and oil without harming performance or carcass yield, and Maurer et al. (2016) reached a similar conclusion for soybean cake in layer diets.

The limits appear at higher inclusion. Dabbou et al. (2018) fed graded levels of defatted meal to broilers and observed that the highest level they tested was accompanied by poorer feed efficiency and less favourable gut morphology, while the lower levels were tolerated. Explanations offered in the literature include the dilution of digestible amino acids by chitin, the effect of chitin on protein digestion, and imbalance of minerals when the limestone allowance is not corrected. These explanations are plausible and not mutually exclusive, but trials have seldom been designed to separate them.

6. Gut Health, Carcass and Meat Quality

Two components of the larva have been credited with benefits beyond nutrient supply. Lauric acid and its monoglyceride inhibit some Gram-positive bacteria in vitro, and chitin and its derivatives have been proposed as substrates for the caecal microbiota. Both ideas are reasonable, and both rest largely on laboratory findings and short trials. Whether they translate into fewer enteric problems in commercial flocks has not been established, and the same chitin that may act as a prebiotic at low inclusion is a candidate cause of impaired digestion at high inclusion (Gasco et al., 2019).

Effects on the carcass are small where diets are properly balanced. The clearest change is in the fat. When larval fat replaced soybean oil in finisher diets, performance and carcass traits were unaffected but the fatty acid profile of the meat shifted towards saturated fatty acids (Schiavone et al., 2017b). Full-fat meal can be expected to move the profile in the same direction, in proportion to the amount of larval fat it contributes. Sensory consequences have received little systematic study.

7. Safety, Regulation and the Substrate Question

The appeal of the black soldier fly lies in its ability to convert manure and food waste (Sheppard et al., 1994). Feed law in many places forbids exactly that. The European Food Safety Authority concluded that the hazards of insect products depend chiefly on the substrate and the processing (EFSA Scientific Committee, 2015), and European rules treat farmed insects as farmed animals, which may be fed only materials already permitted as feed. Processed insect protein was first admitted for aquaculture and was authorised for poultry and pigs in 2021 (European Commission, 2021). Rules elsewhere vary widely.

The chemical evidence justifies some of this caution. Larvae reared on contaminated substrate accumulated cadmium, whereas mycotoxins and the pesticides examined were not accumulated (Purschke et al., 2017). Microbial hazards, allergens and veterinary drug residues are reviewed by van der Fels-Klerx et al. (2018). For a feed mill, the implication is that the origin of the substrate belongs in the specification of the ingredient alongside protein and fat.

8. Economic and Environmental Arguments

Larvae meal is often presented as a low-impact protein. Life cycle assessments give a more conditional picture. Smetana et al. (2016) found that the environmental standing of insect products depended heavily on what the insects were fed, with clear advantages only where low-value side streams were used, and Salomone et al. (2017) identified energy use in rearing and drying as a main burden of a food-waste conversion system. The economic case is similarly local. Where soybean meal is imported and costly and labour and residues are cheap, substitution can pay, as the Kenyan study suggested (Onsongo et al., 2018). Where soybean meal is cheap, larvae meal at present prices competes with fish meal more readily than with soybean meal.

9. Gaps and Future Work

Four gaps stand out. First, products are poorly described. Many papers give crude protein and fat but not the substrate, the nitrogen factor, the chitin content or the drying conditions, so results cannot be compared or reproduced. Second, few trials isolate the cause of the decline at high inclusion; designs that hold digestible amino acids, energy and minerals equal while varying chitin would help. Third, most evidence comes from small pens over a single cycle, and the behaviour of the ingredient in commercial houses, with their litter and disease pressure, is largely unreported. Fourth, safety work has concentrated on a handful of contaminants, while the substrates of most interest to low-income producers are the ones least studied.

10. Conclusion

The literature supports the use of black soldier fly larvae meal as a partial replacement for soybean meal in broiler diets, on three conditions: that the particular meal has been analysed, that the diet is formulated on digestible amino acids with the nitrogen and mineral peculiarities of the ingredient taken into account, and that inclusion stays moderate. It does not support treating larvae meal as a like-for-like substitute, and it does not show that the health benefits attributed to lauric acid and chitin are realised in the field. Whether substitution is worthwhile is, in the end, a question of local prices and local law as much as of nutrition.

Conflict of interest

To be declared by the author(s) before publication.

Funding

To be declared by the author(s) before publication.

References

[1] Barragan-Fonseca, K.B., Dicke, M. and van Loon, J.J.A. Nutritional value of the black soldier fly (Hermetia illucens L.) and its suitability as animal feed: a review. Journal of Insects as Food and Feed https://doi.org/10.3920/JIFF2016.0055 3(2), 105-120 (2017).
[2] Cullere, M., Tasoniero, G., Giaccone, V., Miotti-Scapin, R., Claeys, E., De Smet, S. and Dalle Zotte, A. Black soldier fly as dietary protein source for broiler quails: apparent digestibility, excreta microbial load, feed choice, performance, carcass and meat traits. Animal https://doi.org/10.1017/S1751731116001270 10(12), 1923-1930 (2016).
[3] Dabbou, S., Gai, F., Biasato, I., Capucchio, M.T., Biasibetti, E., Dezzutto, D., Meneguz, M., Plachà, I., Gasco, L. and Schiavone, A. Black soldier fly defatted meal as a dietary protein source for broiler chickens: effects on growth performance, blood traits, gut morphology and histological features. Journal of Animal Science and Biotechnology https://doi.org/10.1186/s40104-018-0266-9 9, 49 (2018).
[4] De Marco, M., Martínez, S., Hernandez, F., Madrid, J., Gai, F., Rotolo, L., Belforti, M., Bergero, D., Katz, H., Dabbou, S., Kovitvadhi, A., Zoccarato, I., Gasco, L. and Schiavone, A. Nutritional value of two insect larval meals (Tenebrio molitor and Hermetia illucens) for broiler chickens: apparent nutrient digestibility, apparent ileal amino acid digestibility and apparent metabolizable energy. Animal Feed Science and Technology https://doi.org/10.1016/j.anifeedsci.2015.08.006 209, 211-218 (2015).
[5] EFSA Scientific Committee Risk profile related to production and consumption of insects as food and feed. EFSA Journal https://doi.org/10.2903/j.efsa.2015.4257 13(10), 4257 (2015).
[6] European Commission Commission Regulation (EU) 2021/1372 of 17 August 2021 amending Annex IV to Regulation (EC) No 999/2001 as regards the prohibition to feed non-ruminant farmed animals, other than fur animals, with protein derived from animals. Official Journal of the European Union, L 295 (2021).
[7] Finke, M.D. Estimate of chitin in raw whole insects. Zoo Biology https://doi.org/10.1002/zoo.20123 26(2), 105-115 (2007).
[8] Gasco, L., Biasato, I., Dabbou, S., Schiavone, A. and Gai, F. Animals. fed insect-based diets: state-of-the-art on digestibility, performance and product quality. Animals, 9(4): 170 https://doi.org/10.3390/ani9040170 (2019).
[9] Hale, O.M. Dried Hermetia illucens larvae (Diptera: Stratiomyidae) as a feed additive for poultry. Journal of the Georgia Entomological Society 8, 16-20 (1973).
[10] Janssen, R.H., Vincken, J.-P., van den Broek, L.A.M., Fogliano, V. and Lakemond, C.M.M. Nitrogen-to-protein conversion factors for three edible insects: Tenebrio molitor, Alphitobius diaperinus, and Hermetia illucens. Journal of Agricultural and Food Chemistry https://doi.org/10.1021/acs.jafc.7b00471 65(11), 2275-2278 (2017).
[11] Makkar, H.P.S., Tran, G., Heuzé, V. and Ankers, P. State-of-the-art on use of insects as animal feed. Animal Feed Science and Technology https://doi.org/10.1016/j.anifeedsci.2014.07.008 197, 1-33 (2014).
[12] Maurer, V., Holinger, M., Amsler, Z., Früh, B., Wohlfahrt, J., Stamer, A. and Leiber, F. Replacement of soybean cake by Hermetia illucens meal in diets for layers. Journal of Insects as Food and Feed https://doi.org/10.3920/JIFF2015.0071 2(2), 83-90 (2016).
[13] NRC Nutrient Requirements of Poultry, 9th revised edition. National Research Council, National Academy Press, Washington, DC (1994).
[14] Onsongo, V.O., Osuga, I.M., Gachuiri, C.K., Wachira, A.M., Miano, D.M., Tanga, C.M., Ekesi, S., Nakimbugwe, D. and Fiaboe, K.K.M. Insects for income generation through animal feed: effect of dietary replacement of soybean and fish meal with black soldier fly meal on broiler growth and economic performance. Journal of Economic Entomology https://doi.org/10.1093/jee/toy118 111(4), 1966-1973 (2018).
[15] Purschke, B., Scheibelberger, R., Axmann, S., Adler, A. and Jäger, H. Impact of substrate contamination with mycotoxins, heavy metals and pesticides on the growth performance and composition of black soldier fly larvae (Hermetia illucens) for use in the feed and food value chain. Food Additives & Contaminants: Part A 34(8), 1410-1420 (2017).
[16] Salomone, R., Saija, G., Mondello, G., Giannetto, A., Fasulo, S. and Savastano, D. Environmental impact of food waste bioconversion by insects: application of life cycle assessment to process using Hermetia illucens. Journal of Cleaner Production 140, 890-905 (2017).
[17] Schiavone, A., Cullere, M., De Marco, M., Meneguz, M., Biasato, I., Bergagna, S., Dezzutto, D., Gai, F., Dabbou, S., Gasco, L. and Dalle Zotte, A. Partial or total replacement of soybean oil by black soldier fly larvae (Hermetia illucens L.) fat in broiler diets: effect on growth performances, feed-choice, blood traits, carcass characteristics and meat quality. Italian Journal of Animal Science https://doi.org/10.1080/1828051X.2016.1249968 16(1), 93-100 (2017).
[18] Schiavone, A., De Marco, M., Martínez, S., Dabbou, S., Renna, M., Madrid, J., Hernandez, F., Rotolo, L., Costa, P., Gai, F. and Gasco, L. Nutritional value of a partially defatted and a highly defatted black soldier fly larvae (Hermetia illucens L.) meal for broiler chickens: apparent nutrient digestibility, apparent metabolizable energy and apparent ileal amino acid digestibility. Journal of Animal Science and Biotechnology https://doi.org/10.1186/s40104-017-0181-5 8, 51 (2017).
[19] Sheppard, D.C., Newton, G.L., Thompson, S.A. and Savage, S. A value added manure management system using the black soldier fly. Bioresource Technology https://doi.org/10.1016/0960-8524(94)90102-3 50(3), 275-279 (1994).
[20] Smetana, S., Palanisamy, M., Mathys, A. and Heinz, V. Sustainability of insect use for feed and food: life cycle assessment perspective. Journal of Cleaner Production 137, 741-751 (2016).
[21] Spranghers, T., Ottoboni, M., Klootwijk, C., Ovyn, A., Deboosere, S., De Meulenaer, B., Michiels, J., Eeckhout, M., De Clercq, P. and De Smet, S. Nutritional composition of black soldier fly (Hermetia illucens) prepupae reared on different organic waste substrates. Journal of the Science of Food and Agriculture https://doi.org/10.1002/jsfa.8081 97(8), 2594-2600 (2017).
[22] St-Hilaire, S., Cranfill, K., McGuire, M.A., Mosley, E.E., Tomberlin, J.K., Newton, L., Sealey, W., Sheppard, C. and Irving, S. Fish offal recycling by the black soldier fly produces a foodstuff high in omega-3 fatty acids. Journal of the World Aquaculture Society 38(2), 309-313 (2007).
[23] van der Fels-Klerx, H.J., Camenzuli, L., Belluco, S., Meijer, N. and Ricci, A. Food safety issues related to uses of insects for feeds and foods. Comprehensive Reviews in Food Science and Food Safety https://doi.org/10.1111/1541-4337.12385 17(5), 1172-1183 (2018).
[24] van Huis, A., Van Itterbeeck, J., Klunder, H., Mertens, E., Halloran, A., Muir, G. and Vantomme, P. Edible Insects: Future Prospects for Food and Feed Security. FAO Forestry Paper 171. Food and Agriculture Organization of the United Nations, Rome (2013).
[25] Veldkamp, T. and Bosch, G. Insects: a protein-rich feed ingredient in pig and poultry diets. Animal Frontiers https://doi.org/10.2527/af.2015-0019 5(2), 45-50 (2015).

Article metrics

0 total accesses since publication. 0 citing articles have been indexed to date.