Suitability of Hermetia illucens larvae meal and fat in broiler diets: effects on animal performance, apparent ileal digestibility, gut histology, and microbial metabolites

Can a mixture of Hermetia illucens and Tenebrio molitor meals be feasible to feed broiler chickens? A focus on bird productive performance, nutrient digestibility, and meat quality

Hermetia illucens (HI) and Tenebrio molitor (TM) meals have widely been used in broiler chickens, but their mixture has never been tested. This study investigated the effects of HI and TM meals - alone and as a mixture (MIX, 1:1) - on productive performance, nutrient digestibility, carcass traits, and meat quality of broiler chickens. After assessing the nutrient digestibility of the insect meals (72 26-day-old male broilers, 4 treatments, 9 cages/treatment, 2 birds/cage), a total of 420 1-day-old male broiler chicks were allotted to 7 diets for 37 days (6 pens/diet, 10 birds/pen): C (control), HI5 (5 % HI), HI10 (10 % HI), TM5 (5 % TM), TM10 (10 % TM), MIX5 (5 % MIX), and MIX10 (10 % MIX). In the whole experimental period, better feed efficiency was observed in TM5, TM10 and MIX5 than C, HI10 and MIX10 birds (P < 0.001). Overall, TM5 and MIX5 groups showed the highest slaughtering, ready-to-cook carcass, and chilled carcass weights, while the lowest values were observed in HI10 and MIX10 (P < 0.001). Meat pH and color were limitedly influenced by dietary insect meal inclusion, while higher breast cooking losses were observed in HI10 birds than C, HI5 and MIX5 (P < 0.001). Higher breast dry matter was observed in HI5 birds than TM5 and HI10 (P < 0.001), with the same broilers displaying greater breast crude protein than TM5 (P < 0.001). The highest and lowest percentage of monounsaturated and polyunsaturated fatty acids, respectively, were observed in TM10 birds, along with the lowest polyunsaturated:saturated fatty acids ratio (P < 0.001). The TM5, HI5 and HI10 meat displayed lower tenderness than C meat (P = 0.001), with lower juiciness and overall liking being also overall identified for TM5 (P < 0.05). In conclusion, including 5 % of TM and MIX meals in diets for broiler chickens improved growth performance and carcass traits, while the 10 % inclusion level of HI and MIX meals was associated with the worst outcomes. Including 10 % of HI meal or using TM meal (mainly 5 %) also worsened meat quality and consumer perception.

Dietary Protein Levels in Isoenergetic Diets Affect the Performance, Nutrient Utilization and Retention of Nitrogen and Amino Acids of Hermetia illucens (L.) (Diptera: Stratiomyidae) Larvae

Black soldier fly, H. illucens larvae, efficiently convert low-value organic substrates into high-value products, offering solutions to global challenges in sustainable food production and biotechnology. This study investigated the impact of dietary protein levels (10%, 14%, 16%, and 20% crude protein, CP) on BSFL growth, nutrient utilization, and energy retention using isoenergetic diets (18.5 ± 0.3 MJ/kg dry matter) under commercial-scale conditions. Larvae were harvested after 8 days of feeding, with 5 replicates per treatment. Optimal growth performance and feed conversion ratios were observed in larvae fed 14% CP diet, with a quadratic relationship between dietary CP and biomass gain (p < 0.001, R2 = 0.870). Ash and calcium deposition peaked in CP20-fed larvae and were lowest in CP14-fed larvae. Phosphorus and glucosamine deposition remained unaffected, while chitin deposition correlated positively with larval weight. Nitrogen and amino acid retention were highest in CP14-fed larvae but reduced in CP20-fed larvae (p < 0.001, R2 = 0.573-0.902). CP10-fed larvae showed impaired growth and nitrogen deposition but increased fat deposition. These findings establish the CP14 diet as the optimal formulation for scalable BSFL production, providing critical insights into dietary protein effects on BSFL physiology and enabling the development of efficient feeding strategies for industrial-scale farming.

Effect of black soldier fly (Hermetia illucens) larvae meal and oil on the performance, biochemical profile, intestinal health and gut microbial dynamics in laying hens

This study investigated the effect of incorporating black soldier fly (BSF) larvae meal and oil on laying hens' performance, egg quality, serum profile, intestinal structure, and gut health. A total of 378 Lohmann laying hens (age 48 wk) were randomly assigned to 6 treatments with 3 replicates of 21 hens each. Following 7 d acclimation, the trail was conducted for 8 weeks. The dietary groups include: basal corn-soybean meal diet (S) without BSF (BSO) oil (S+BSO 0), S with BSF oil (S+BSO 100), BSF meal (9 %) without BSF oil (BSF 9+BSO 0), BSF meal (9 %) with BSF oil (BSF 9+BSO 100), BSF meal (18 %) without BSF oil (BSF 18+BSO 0), and BSF meal (18 %) with BSF oil (BSF 18+BSO 100). The results showed that the BSF 18 + BSO 100 diet significantly reduced egg weight (P < 0.001) compared to other dietary treatments. The addition of BSF meal reduced feed intake (P < 0.001) and the Haugh units (P < 0.05) in hens fed 18 % BSF meal with and without BSO. The jejunum villus area, crypt depth, and intestinal wall thickness increased with the increase in the inclusion of BSF larvae meal (P < 0.001). The ileum villus height, crypt depth and intestinal wall thickness increased (P < 0.001) at 9 % BSF meal and then decreased at 18 % BSF meal with and without BSF oil. The bacteria genera Ruminococcus, Clostridiales, Bacteroidales, Ruminococcus torques, and Intestinimonas were positively associated with the dietary treatments, while Prevotellaceae UCG-001, Clostridium, and Faecalibacterium were negatively associated with the dietary treatments. The inclusion of BSF meal and oil enriched the functional network of several pathways, including ascorbate and aldarate metabolism, D-arginine and D-ornithine metabolism, and fatty acid metabolism, highlighting the positive effects of BSF larvae meal and oil on the chicken gut microbiota. In conclusion, BSF meal at 9 % with BSF oil and BSF meal at 18 % without BSF oil can be incorporated into the diet without impairing the performance and gut health of laying hens.

Assessing the performance, egg quality, serum analysis, heavy metals and essential trace metals accumulation in laying hen eggs and tissues fed black soldier fly (Hermetia illucens) larvae meal

Black soldier fly (BSF) larvae convert wastes into protein, playing a vital role in addressing the challenge of sustainable poultry production. These larvae accumulate toxic substances, posing a risk to feed and food safety. This study investigates the effects of substituting soybean meal with different levels of BSF larvae meal on laying performance, egg quality, serum analysis, and the deposition of various metals in eggs, meat, and excreta. A total of 1,008 Lohmann hens (age 48 wk) were randomly assigned to 4 treatments. The treatments consisted of corn-soybean meal (CK) diet replaced with 7% (BSF7), 14% (BSF14), and 21% (BSF21) BSF larvae meal. Each treatment consisted of 6 replicates with 42 hens each and the trial lasted for 8 wk. Dietary BSF larvae meal treatments increased (linear, P < 0.05) the laying rate (1.52 to 1.95%) and decreased (linear, P < 0.01) the feed intake (3.64-3.86 g) during the entire experiment. During 48 to 52 wk, egg weight was decreased (P < 0.001) 0.93 g for the BSF21 group compared to CK group, however, during 52-56 wk, no differences in egg weight were observed among treatments. The addition of BSF larvae meal enhanced the eggshell strength (linear, P < 0.05), with no effect on the albumen height and yolk weight (P > 0.05). Low transfer of arsenic, lead, and cadmium concentration was observed in the egg yolk and egg white across different treatments (P > 0.05). Conversely, the concentrations of these metals and iron showed an increase, while Zinc exhibited a decrease in excreta as the dietary intake of BSF larvae meal increased. The chromium and iron increased linearly (P < 0.001) in the egg white with the inclusion of BSF larvae meal. Egg white iron and chromium showed a strong positive correlation with the dietary zinc and copper. Taken together, BSF larvae can replace soybean meal completely in laying diet, however, careful attention requires to elevated metal levels in diet and excreta.

Nano-emulsified black soldier fly oil concerning performance traits, health, and immunity of broilers

In the antibiotic-free era, traditional antibiotics have been suggested as alternatives to antibiotic-based growth promoters. Among the various methods, self-nano-emulsifying drug delivery systems (SNEDDS) are increasingly utilized to improve the bioavailability of oils containing essential substances. In this study, we evaluated the effects of black soldier fly oil (BSFO) SNEDDS in chicken drinking water on growth performance, small intestine histomorphology, and poultry health status. We divided 225 male Indian River strain broiler chickens into five treatment groups, each consisting of 5 replicates. The chickens were reared from to 0 to 35 d of age in a controlled environmental housing system. The BSFO SNEDDS was administered via drinking water. Treatments included ordinary drinking water (P1), bacitracin (P2), and 10 mL/L (P3), 20 mL/L (P4), and 30 mL/L (P5) BSFO SNEDDS. The observed parameters included growth performance, carcass yield, blood hematology, intestinal histomorphology, digestive microflora, and immunoglobulin (Ig) levels. Data were analyzed using analysis of variance (ANOVA) and Duncan's test. The results indicated that administering BSFO SNEDDS via drinking water improved feed conversion (P < 0.05), enhanced the performance index (P < 0.05), increased carcass percentage (P < 0.001), and increased the weight of the carcass parts. Additionally, it increased villus height (P < 0.01), lowered jejunal pH (P < 0.001), reduced pathogenic bacteria in the jejunum, and decreased the leukocyte count. BSFO SNEDDS in drinking water is expected to be used as a traditional antibiotic with the potential to replace synthetic antibiotic growth promoters in broiler chickens.

Estimation of the digestible energy value of fat obtained from black soldier fly larvae (Hermetia illucens) for growing pigs

An experiment was conducted to determine the digestible energy (DE) of insect fat (IF) from black soldier fly larvae (BSLF) for growing pigs. Saturated fatty acids (SFA) were the dominant group of fatty acids in the IF, with lauric acid (C12:0) and palmitic acid (C16:0) comprising the greatest concentrations in this group. Linoleic acids (C18:2) and oleic acids (C18:1) were the main unsaturated fatty acids. The IF contained 37.63 MJ/kg gross energy and 2.55 g/kg nitrogen. During the experiment, a DE bioassay was performed wherein growing pigs were fed one of the two experimental diets (either a maize-wheat-barley-soy basal diet or a diet containing 50 g/kg IF plus 950 g/kg of the basal diet). The DE of the IF was calculated based on the differences between the DE values of basal and test diet (substitution method). The DE of the IF was determined to be 36.86 MJ/kg. The IF contains a DE level comparable to vegetable oils, including soybean, rapeseed, corn and palm oils. The results showed that the examined fat from BSLF is a good source of available energy and can be incorporated in pig diets as an alternative energy source.

A Systematic Review and Metanalysis on the Use of Hermetia illucens and Tenebrio molitor in Diets for Poultry

Insect meal as a protein source has been considered a sustainable way to feed animals. H. illucens and T. molitor larvae meal are considered high-protein sources for poultry, also presenting considerable amounts of fatty acids, vitamins, and minerals. However, other potential components in insect meal and insect oil have been more extensively studied in recent years. Chitin, lauric acid, and antimicrobial peptides can present antimicrobial and prebiotic functions, indicating that low levels of their inclusion in insect meal can beneficially affect broilers' health and immune responses. This systematic review was developed to study the impact of insect products on the health parameters of broilers, and a metanalysis was conducted to evaluate the effects on performance. A database was obtained based on a selection of manuscripts from January 2016 to January 2023, following the mentioned parameters. Both H. illucens and T. molitor meal or oil products had positive effects on poultry health status, especially on the ileal and cecal microbiota population, immune responses, and antimicrobial properties. The average daily gain was greater in broilers fed T. molitor meal compared to H. illucens meal (p = 0.002). The results suggest that low levels of insect meal are suitable for broilers, without resulting in negative effects on body weight gain and the feed conversion ratio, while the insect oil can totally replace soybean oil without negative impacts.

Endogenous chitinase might lead to differences in growth performance and intestinal health of piglets fed different levels of black soldier fly larva meal

This study aimed to investigate the effects of different levels of black soldier fly (BSF) replacing soybean meal (SBM) in diets on the performance and health condition of piglets. A total of 180 weaned piglets were allocated into 5 treatments: BSF0 (corn-soybean meal basal diet), BSF25 (BSF replacing 25% SBM), BSF50 (BSF replacing 50% SBM), BSF75 (BSF replacing 75% SBM) and BSF100 (BSF replacing 100% SBM). During the whole period, in comparison with BSF0, average daily gain (ADG) and average daily feed intake increased in the BSF25 and BSF50 groups, whereas ADG decreased in the BSF75 and BSF100 groups (P < 0.05). The result of quadratic fitting curve showed that piglets exhibited the highest ADG when BSF replaced around 20% SBM. Compared with BSF0, organic matter and dry matter digestibility improved in the BSF25 group, whereas ether extract digestibility decreased in the BSF100 group (P < 0.05). In comparison with BSF0, piglets from the BSF25 group showed a higher duodenal ratio of villus height to crypt depth, increased jejunal sucrase activity, serum neuropeptide Y and ghrelin levels, elevated ileal immunoglobulin (Ig) A, IgG and IgM contents and a lower leptin level, and piglets from the BSF100 group exhibited an increased relative weight of kidney (P < 0.05). However, no significant differences were observed in the expression level of tight junction proteins and chitin-degrading enzyme. Additionally, compared with BSF0, the abundance of short chain fatty acid producing bacteria such as Ruminococcaceae, Faecalibacterium and Butyricicoccus increased, and potential pathogenic bacteria decreased in piglets from the BSF25 group, whereas piglets from the BSF100 group had a greater abundance of harmful bacteria. In conclusion, BSF replacing 25% SBM in diets could improve digestive parameters, immune function and intestinal microbiota, and thus improved growth performance of piglets. However, BSF replacing 100% SBM showed an adverse effect on piglet performance, and the reason might be related to the limited amount of chitin-degrading enzyme.

Effect of replacement of soybean oil by Hermetia illucens fat on performance, digestibility, cecal microbiome, liver transcriptome and liver and plasma lipidomes of broilers

BACKGROUND

In contrast to protein-rich insect meal, the feed potential of insect fat is generally less explored and knowledge about the suitability of insect fat as a fat source specifically in broiler diets is still limited. In view of this, the present study aimed to comprehensively investigate the effect of partial (50%) and complete replacement of soybean oil with insect fat from Hermetia illucens (HI) larvae in broiler diets on performance, fat digestibility, cecal microbiome, liver transcriptome and liver and plasma lipidomes. Thus, 100 male, 1-day-old Cobb 500 broilers were randomly assigned to three groups and fed three different diets with either 0 (group HI-0, n = 30), 2.5% (group HI-2.5, n = 35) or 5.0% (HI-5.0, n = 35) Hermetia illucens (HI) larvae fat for 35 d.

RESULTS

Body weight gain, final body weight, feed intake, and feed:gain ratio during the whole period and apparent ileal digestibility coefficient for ether extract were not different between groups. Cecal microbial diversity did not differ between groups and taxonomic analysis revealed differences in the abundance of only four low-abundance bacterial taxa among groups; the abundances of phylum Actinobacteriota, class Coriobacteriia, order Coriobacteriales and family Eggerthellaceae were lower in group HI-5.0 compared to group HI-2.5 (P < 0.05). Concentrations of total and individual short-chain fatty acids in the cecal digesta were not different between the three groups. Liver transcriptomics revealed a total of 55 and 25 transcripts to be differentially expressed between groups HI-5.0 vs. HI-0 and groups HI-2.5 vs. HI-0, respectively (P < 0.05). The concentrations of most lipid classes, with the exception of phosphatidylethanolamine, phosphatidylglycerol and lysophosphatidylcholine in the liver and cholesterylester and ceramide in plasma (P < 0.05), and of the sum of all lipid classes were not different between groups.

CONCLUSIONS

Partial and complete replacement of soybean oil with HI larvae fat in broiler diets had no effect on growth performance and only modest, but no adverse effects on the cecal microbiome and the metabolic health of broilers. This suggests that HI larvae fat can be used as an alternative fat source in broiler diets, thereby, making broiler production more sustainable.

Genetic diversity and organic waste degrading capacity of Hermetia illucens from the evergreen forest of the Equatorial Choco lowland

Globally, microplastics (MP) represent a growing burden for ecosystems due to their increasing presence at different trophic levels. In Ecuador, the lack of waste segregation has increased the quantity of waste, primarily organics and plastics, overloading landfills and water sources. Over time, plastics reduce in size and silently enter the food chain of animals, such as insects. The black soldier fly (BSF) larvae, Hermetia illucens (Linnaeus, 1758), is a species with devouring behavior used for waste management because of its beneficial qualities such as fly pest control, biomass production, and rapid organic waste degradation. Studies have uncovered the insect's ability to tolerate MP, and consider the possibility that they may be able to degrade polymers. For the first time in Ecuador, the present study characterized H. illucens using the sequences of different molecular markers. Finally, H. illucens' degrading capacity was evaluated in the presence of MP and decaying food residues, resembling landfill conditions.

Bioconversion of fruit waste and sewage sludge mixtures by black soldier fly (Diptera: Stratiomyidae) larvae

Bioconversion of fruit waste (FW) and sewage sludge (SS) sludge mixtures into valuable products was investigated using black soldier fly (Hermetia illucens) larvae (BSFL) under a lab-scale trial. For that, five different setups of FW and SS mixtures (100FW; 100SS; 70SS+30FW; 50SS+50FW; 70FW+30SS) were prepared and changes in larval biomass, feed loss, and residual waste physicochemical properties were estimated until the emergence of fly in all waste mixtures. BSFL caused a significant decrease in total organic carbon (11.71-34.79%) and carbon-to-nitrogen ratio (C/N ratio) while the increase in total nitrogen (8.35-123.30%), total phosphorus (17.02-143.36%), and total potassium (19.40-48.87%) contents in the feedstock. The germination index and C/N ratio of frass were below the standards decided for manure quality in a few setups suggesting the non-stability of frass for agronomic applications due to the short duration (20 d) of composting. Larval biomass yield, feed conversion ratio and nutrient mineralization were found to be higher in 50SS+50FW and 70FW+30SS feedstock combinations suggesting their suitability as ideal feedstock for optimal BSFL cultivation. The impact of toxic substances in sewage on BSFL survival, growth and waste stabilization processes, and frass metal enrichment could be investigated in future studies.