Black Soldier Fly Larvae Meal Research Articles

A Sustainable Diet for Tambaqui Farming in the Amazon: Growth Performance, Hematological Parameters, Whole-Body Composition and Fillet Color

The aim of this study was to produce feed based on locally sourced ingredients for tambaqui farming in Amazon. Diets were formulated with increasing levels (0, 25, 50, 75 and 100%) of defatted black soldier fly larvae meal (BSFL) as a replacement for fish meal (FM), and cassava by-products in the same proportion (tuber residues, peel and leaves). A conventional diet (CO) was used as the control. Juvenile tambaqui (24.61 ± 1.14 g) were housed in 24 tanks in a recirculation aquaculture system. Neither diet rejection nor mortality were observed. Fish fed cassava by-products showed similar feed conversion rates (FCR 1.76); however, these values were worse than those observed in fish fed the CO (FCR 1.33). No differences were observed in the whole-body composition of the fish. The fillets of fish fed cassava by-products had a yellow color due the carotenoids present in the leaves. Dietary BSFL and cassava by-products can contribute to the sustainability of Amazonian aquaculture. Further studies with a lower proportion of cassava leaves in the diet formulation are recommended so as to ensure enhanced diet digestibility and less impact on the color of the fillets.

Hermetia illucens Larvae Meal as Partial Fishmeal Replacement in Jade Perch Diet Cultured in Biofloc: Growth Performance, Feed Efficiency and Consumer Acceptance

A 12-week feeding trial on jade perch (Scortum barcoo) was conducted to evaluate the outcomes of partial substitution of fishmeal with black soldier fly larvae meal (BSFLM) in a biofloc system that requires minimal water exchange. The jade perch juveniles were subjected to three dietary treatments namely the 100% fishmeal (FM100), 50% BSFLM (BSF50), and a commercial diet (COM) with 20 individuals per treatment in triplicate tanks. Growth, feed efficiency, and body indices were measured throughout the feeding trial. There were no significant differences observed between the treatments in growth indicators such as the body weight gain (84.55 - 89.10 g), feed conversion ratio (1.77 - 1.87), specific growth rate (1.71 - 1.81 %/day), protein efficiency ratio (1.69 - 1.77), survival rate (90.00 - 98.48 %) and fillet yield (34.94 - 37.08 %). The condition factor is similar in all treatment groups ranging from 1.97 - 2.05. The crude protein and moisture content making up fish body composition are not statistically different among treatments, but higher crude lipids are obtained in the BSF50 (32.33 ± 5.27 g/kg) and COM (31.67 ± 2.76 g/kg). Higher hepatosomatic index (HSI) and visceral fat somatic index (VFSI) values were observed in BSF50 group at 3.13 ± 0.25 and 10.89 ± 1.68, respectively. Furthermore, sensory evaluation comparing the consumers' evaluation and acceptance of the fish cultured with the different dietary treatment and culture system shows that the group fed BSF50 and cultured in biofloc system received similar overall appreciation with the FM100 and COM group. In conclusion, BSFLM inclusion in the jade perch diet, combined with the biofloc system, is feasible to be explored further.

Black Soldier Fly Larvae Meal vs. Soy Protein Concentrate Meal: A Comparative Digestibility Study in Barramundi (Lates calcarifer)

Black soldier fly larvae meal (BSFM) from Hermetia illucens has emerged as a dependable protein source in aquaculture. This study aimed to assess BSFM’s digestibility in barramundi juveniles and compare it to soy protein concentrate meal (SPCM). Four diets (control, 30% BSFM; 30% SPCM; and commercial feed control) were tested on 1,800 barramundi juveniles (weight: 71.1 g) over 51 days in a recirculating aquaculture system (RAS). The final body weight (FBW) of fish fed with BSFM reached 222.2 (± 8.7), with a thermal-unit growth coefficient (TGC) of 4.33 (± 0.15) and a feed conversion ratio (FCR) of 1.04 (± 0.01). While BSFM and SPCM inclusion did not significantly impact FBW, body weight gain (BWG), TGC, or survival rates (P >0.05), FCR increased. BSFM significantly raised total feed intake (P<0.05) but did not affect daily feed intake (P >0.05). Importantly, BSFM and SPCM inclusion did not alter diet apparent digestibility coefficient (ADC) for any nutrient groups (P >0.05), with BSFM showing high ADC for dry matter (76.8%), crude protein (93.2%), and gross energy (83.9%). No significant difference (P >0.05) was observed in these ADCs between BSFM and SPCM. The high digestibility of BSFM in warm seawater RAS (29.4°C) under high stocking density (33.7 kg m−3) supports its efficacy in contemporary barramundi farming.

Black Soldier Meal in Feed Could Adversely Affect Organic Broiler Meat Quality When Used for the Total or Half Replacement of Diet Proteins

Organic poultry sector needs high-quality proteins sources to meet specific requirements. The EU’s organic regulation forbids synthetic amino acids; therefore, soybean, with its balanced essential amino acid content, has become the most used protein source, though much of it is imported from non-EU countries, with sustainability and crop competition issues; therefore, it should be substituted with a high-protein-value alternative such as insect meal. In this study, 900 Aviagen Savanna broilers were fed with three different organic diets: soybean only (S100), 50% black soldier fly larvae meal (BSL) and 50% soybean (BSL50), and 100% BSL only (BSL100). Broiler performance, welfare, and fatty acids (FA) were analyzed. BSL50 and BSL100 negatively affected growth, while only BSL100 worsened all of the market-related performances. Meat showed a significant increase in saturated FA (SFA) (p < 0.000) and a corresponding decrease in polyunsaturated FA (PUFA), in BSL50 and BSL100, but α-linolenic acid was not affected by BSL50 treatment (p < 0.000). The SFA increase could represent a negative aspect for human health (e.g., cardiovascular diseases), but, as reported by other authors, medium chain SFA, (i.e., lauric acid), may show beneficial effects as well (i.e., antibacterial, anti-inflammatory and antioxidant properties).

Dynamic effects of black soldier fly larvae meal on the cecal bacterial microbiota and prevalence of selected antimicrobial resistant determinants in broiler chickens

BackgroundWe had earlier described the growth-promoting and -depressive effects of replacing soybean meal (SBM) with low (12.5% and 25%) and high (50% and 100%) inclusion levels of black soldier fly larvae meal (BSFLM), respectively, in Ross x Ross 708 broiler chicken diets. Herein, using 16S rRNA gene amplicon sequencing, we investigated the effects of replacing SBM with increasing inclusion levels (0-100%) of BSFLM in broiler diets on the cecal bacterial community composition at each growth phase compared to broilers fed a basal corn-SBM diet with or without the in-feed antibiotic, bacitracin methylene disalicylate (BMD). We also evaluated the impact of low (12.5% and 25%) inclusion levels of BSFLM (LIL-BSFLM) on the prevalence of selected antimicrobial resistance genes (ARGs) in litter and cecal samples from 35-day-old birds.ResultsCompared to a conventional SBM-based broiler chicken diet, high (50 to100%) inclusion levels of BSFLM (HIL-BSFLM) significantly altered the cecal bacterial composition and structure, whereas LIL-BSFLM had a minimal effect. Differential abundance analysis further revealed that the ceca of birds fed 100% BSFLM consistently harbored a ~ 3 log-fold higher abundance of Romboutsia and a ~ 2 log-fold lower abundance of Shuttleworthia relative to those fed a BMD-supplemented control diet at all growth phases. Transient changes in the abundance of several potentially significant bacterial genera, primarily belonging to the class Clostridia, were also observed for birds fed HIL-BSFLM. At the finisher phase, Enterococci bacteria were enriched in the ceca of chickens raised without antibiotic, regardless of the level of dietary BSFLM. Additionally, bacitracin (bcrR) and macrolide (ermB) resistance genes were found to be less abundant in the ceca of chickens fed antibiotic-free diets, including either a corn-SBM or LIL-BSFLM diet.ConclusionsChickens fed a HIL-BSFLM presented with an imbalanced gut bacterial microbiota profile, which may be linked to the previously reported growth-depressing effects of a BSFLM diet. In contrast, LIL-BSFLM had a minimal effect on the composition of the cecal bacterial microbiota and did not enrich for selected ARGs. Thus, substitution of SBM with low levels of BSFLM in broiler diets could be a promising alternative to the antibiotic growth promoter, BMD, with the added-value of not enriching for bacitracin- and macrolide-associated ARGs.

Evaluating the fillet quality and sensory characteristics of Atlantic salmon (Salmo salar) fed black soldier fly larvae meal for whole production cycle in sea cages

There is scarce research on the use of black soldier fly larvae (BSFL) meal in the diets of Atlantic salmon (Salmo salar) reared in a real farm. Thus, the current study aimed to evaluate the effect of feeding BSFL meal to salmon in terms of fillet quality and sensory analysis at farm level conditions. Fish were fed a total of three diets (pellet size; 4.5 mm and 9 mm); a control diet (Control: 0% BSFL meal) formulated using a standard commercial recipe, containing FM (10%) and plant-based proteins. Two experimental diets were formulated using partially defatted BSFL meal (53% crude protein), in which plant-based proteins at 37% inclusion level from the control diet (4.5 mm pellets) were replaced by BSFL meal at 5% (BSFL 5%) and 10% (BSFL 10%). While for the 9.0 mm pellets, plant-based proteins at 35% were replaced by the BSFL meal at 5% and 10% inclusion level. All the three diets were formulated to be iso-nitrogenous and iso-lipidic diets. Diets were assigned to the sea-cages in triplicate (12 ×12 m; 1900 m3); housing ∼6000 fish per cage from 173 ± 2.7 g to harvest size 3.45 ± 74 kg for a period of 13 months. Feeding salmon with BSFL meal had no negative impact on the general fillet physical, chemical, and nutritional parameters. The fillet sensory evaluation showed that the control samples were associated with the typical attributes such as fresh salmon taste, while BSLF 10% to rancid taste but these attributes were not significantly different among the dietary groups. Overall, the current study showed that diet containing BSFL meal did not affect the general fillet parameters compared to salmon fed a commercial diet and thus validate the inclusion of BSFL meal up to 10% reared for a whole production cycle in sea cages.

Black soldier fly (Hermetia illucens) larvae meal improves quail growth performance.

The aim of the present study was to determine the nutritional value of black soldier fly (BSF) larvae meal for quail (experiment I) and the dose-response effects of BSF levels on growth performance, relative organ weight, and body composition of growing quails (experiment II). In experiment I, 100 35-day-old quail were distributed in a completely randomized design, with two treatments (reference and test diet) and 10 replicates. The experimental period consisted of 5days of adaptation, followed by 5days of total excreta collection. The experimental feed consisted of a reference diet and a test diet formulated with 850g/kg reference diet and 150g/kg BSF. In experiment II, 1000 1-day-old quail were distributed in a completely randomized design, with five dietary levels of BSF (0, 25, 50, 75, and 100g/kg). At 42days of age, birds were slaughtered, and the relative organ weight and body composition were determined. Apparent metabolizable energy values corrected for nitrogen retention of BSF meal were 13.8MJ/kg. Across the starter (1-14days) and overall period (1-42days), increasing BSF levels had a quadratic effect on body weight and body weight gain. Feed conversion ratio was quadratically affected during the starter phase and linearly reduced over the overall period. Additionally, the BSF levels linearly decreased the small intestine's relative weight at 42days and had a quadratic effect on the rate of protein deposition. We concluded that the inclusion of 100g/kg BSF meal improves feed conversion ratio for growing quail.

Black Soldier Fly (Hermetia illucens) Larvae Meal: A Sustainable Alternative to Fish Meal Proven to Promote Growth and Immunity in Koi Carp (Cyprinus carpio var. koi)

Insect meal has shown promise as a potentially sustainable source of nutrients for aquafeeds, offering an alternative to expensive and ecologically undesirable ingredients, in the context of population explosion and climate change. Despite this promising outlook, its effects on fish growth and immune responses remain to be thoroughly investigated. Our scientific goal was to experimentally test responses to replacements of the fish meal with a protein source derived from black soldier fly larvae meal (BSFLM). Possible impacts on growth, immunological response, and the expression of selected immune-system related genes were evaluated in Koi carp (Cyprinus carpio var. koi) using a biofloc culture system. Three hundred fish (20.0 ± 0.2 g) were allocated into five groups: a control group receiving a basal diet containing 0 g kg−1 BSFLM and four experimental groups in which fish meal was replaced with 50, 100, 150, and 200 g kg−1 BSFLM for eight weeks. After 4 weeks of feeding, there were no statistically significant differences in specific growth rate (SGR), feed conversion ratio (FCR), and survival rate between fish fed BSFLM-enriched diets at 50, 100, 150 g kg−1 and a control (0 g kg−1 BSFLM) diet. However, fish fed 200 g kg−1 BSFLM showed significantly improved weight gain (WG) and SGR compared to the control after 4 weeks; this difference persisted through 8 weeks (p < 0.05). After eight weeks, there was a moderate to weak negative linear regression shown in FCR (r = 0.470) and SR (r = 0.384), respectively, with the BSFLM levels, but significant and highly correlated linear relationships were observed in WG (r = 0.917) and SGR (r = 0.912). Immunological response analysis showed slight changes in lysozyme and peroxidase levels by replacing fish meal with BSFLM, but these apparent differences were not significantly related to experimental diets. Interestingly, mRNA transcripts of immune-related genes (TNF-α, TGF-β, IL1, IL10, and hsp70) were upregulated in the groups receiving higher amounts of BSFLM, with statistically significant differences observed in certain comparisons. Our findings reveal that fish meal can be effectively replaced by BSFLM, and that this not only has a positive effect on immune-related gene expression in Koi carp, but also on growth rate, pointing to the future potential role of BSFLM as an alternative fish meal protein in aquafeed formulation.

Evaluation of Black Soldier Fly Larvae Meal on Growth, Body Composition, Immune Responses, and Antioxidant Capacity of Redclaw Crayfish (Cherax quadricarinatus) Juveniles

This study investigated the effects of substituting fish meal (FM) with black soldier fly (Hermetia illucens) meal (BSM) on the growth performance, body composition, immune response, and antioxidant enzyme activity of juvenile redclaw crayfish (Cherax quadricarinatus). Four isonitrogenous (41%) and isolipidic (11%) diets (i.e., FM substitutes) were formulated from BSM prepared using larvae that were fed soybean meal (BSM-S), fishery byproducts (BSM-F), or pitaya (BSM-P). The experimental diets were fed twice daily to triplicate groups of juvenile redclaw crayfish (0.56 ± 0.04 g). After the feed trial, the FM and BSM-F groups exhibited significantly lower feed conversion ratios and significantly higher weight gain; specific growth rates; and concentrations of saturated fatty acids, highly unsaturated fatty acids, eicosapentaenoic acid, and docosahexaenoic acid in the muscle. Among the tested groups, the BSM-F group exhibited significantly enhanced immune responses and increased antioxidant enzyme activity (i.e., superoxide dismutase, phenoloxidase, and glutathione peroxidase); the BSM-P group exhibited a significantly higher feed intake and hepatopancreatic index; and the FM group exhibited a significantly higher muscle body index and apparent digestibility for the dry matter of crude protein. The findings indicate that the juvenile redclaw crayfish fed BSM-F achieved the highest weight gain among the groups.

Integrating Black Soldier Fly (Hermetia illucens) Larvae Meal in Aquaponics System for Lettuce (Lactuca sativa) Production

The adoption of aquaponics systems faces challenges due to the high cost of fish feed, lack of sustainability, and reliance on fishmeal as a primary input. One potential solution to replace fishmeal is the use of black soldier fly larvae (BSFL) in aquaponics. The study aimed to explore the effect of substituting fish meals with BSFL meals on the growth performance of lettuce (Lactuca sativa) in aquaponics. The study employed the Randomized Complete Block Design (RCBD). A total of 135 catfish fingerlings were divided into three groups and stocked in nine water barrels of 100 litres each (filled with 60 litres of water). The fingerlings were fed twice a day for a duration of 56 days after a two-week period of acclimatisation using commercial feed. Water was cycled through the hydroponic media grow bed using an automatic timer, with a 15-minute cycle every hour throughout the day and night. Fish meal was replaced with BSFL meal at three different proportions: 0% (BSFL0), 30% (BSFL30), and 50% (BSFL50). The data collected was analysed using One-Way Analysis of Variance (ANOVA) and Kruskal-Wallis tests, followed by Tukey's ad-hoc and Dunn's tests, respectively, utilising JMP 16 software. The results indicated that the fresh leaf weight was significantly influenced by the diet types (p<0.05). However, no significant effect was observed on root weight, total dry weight, number of leaves, or root length (p>0.05). This study suggests that black soldier fly larvae meal can successfully replace up to 50% of fishmeal in aquaponics without compromising lettuce growth performance. Therefore, promoting the use of black soldier fly larvae meal can contribute to the sustainability of lettuce production in aquaponics

Growth and Hepatopancreas Health of Juvenile Chinese Mitten Crab (Eriocheir sinensis) Fed Different Levels of Black Soldier Fly (Hermetia illucens) Larvae Meal for Fish Meal Replacement.

A 56-day feeding trial assessed the effects of black soldier fly larvae meal (BSFLM) on the growth performance and hepatopancreas health of juvenile Eriocheir sinensis. Six isoproteic and isolipidic diets with 0% (FM), 10% (BSFLM10), 20% (BSFLM20), 30% (BSFLM30), 40% (BSFLM40), or 50% (BSFLM50) replacement of fish meal by BSFLM were formulated. Compared to FM, replacing 10%-40% of fish meal with BSFLM did not significantly affect the weight gain rate (WGR) or specific growth rate (SGR), while BSFLM50 significantly decreased the WGR and SGR. Crabs fed BSFLM50 had significantly lower T-AOC activity than those fed other diets, and crabs fed BSFLM30, BSFLM40, or BSFLM50 had significantly lower activities of antioxidant enzymes (SOD and GSH-Px) in the hepatopancreas than those fed FM or BSFLM10. Compared to FM, BSFLM10, BSFLM20, and BSFLM30 did not affect the relative expression of genes related to the nonspecific immunity, while BSFLM40 and BSFLM50 upregulated the relative expression of these genes. Furthermore, histological analysis showed that the hepatopancreas was deformed in the BSFLM50 group, with widened lumens and loss of basal membrane integrity. In summary, BSFLM replacing 50% of fish meal reduced growth and structural damage to the hepatopancreas. An immune response was activated when the replacement level was over 30%. Therefore, the replacement level of dietary fish meal by BSFLM is recommended to be not more than 30% of the juvenile E. sinensis feed.

Effects of Partial Replacement of Soybean with Local Alternative Sources on Growth, Blood Parameters, Welfare, and Economic Indicators of Local and Commercial Broilers.

The effects of the partial replacement of soybean with alternative local agri-industry by-products and black soldier fly (BSF) larvae meal on broiler growth performance, blood biochemistry, welfare, and, subsequently, economic performance of these diets were evaluated. A total of 524 day-old chicks from a local and a commercial strain were fed one of the three diets from the day of hatch to the slaughter age. The diets were the following: a soybean-based control diet, a diet in which soybean was partially replaced (SPR) with agri-industrial by-products, or a diet with BSF larvae meal added to the SPR (SPR + BSF). There was no effect of the diets on the slaughter weight, total feed consumption, and feed conversion of the chickens. The SPR + BSF diet reduced the blood glucose, alanine aminotransferase, aspartate aminotransferase, gamma-glutamyl transferase, protein, triglycerides, and cholesterol levels in the local chickens and the gamma-glutamyl transferase, protein, and creatinine levels in the commercial broilers. The negative effect of the SPR diet on plumage cleanliness in the commercial broilers was alleviated by the SPR + BSF diet, whereas 100% of the local birds presented either slight or moderate soiling. The results showed that, due to the high cost of the BSF larvae meal, the SPR + BSF diet was not economically feasible. In a further study, the price trends of BSF larvae will be examined from the standpoint of economic profitability conditions.

Effects of different black soldier fly larvae products on slow-growing broiler performance and carcass characteristics

Black soldier fly (BSF) larvae have gained significant attention as ingredients for poultry feed to improve value chain circularity and sustainability. BSF larvae contain bioactive compounds which can potentially improve broiler health and thereby performance. However, the functionality of bioactive compounds likely depends on how larvae are processed prior to feeding and to which extent larvae products are included in the diet. This may explain the variable results reported in literature on broiler performance and carcass characteristics when feeding them different types of BSF larvae products at different inclusion levels. Therefore, the present research aimed to investigate the effects of different BSF larvae products and inclusion levels in diets on performance and carcass characteristics of slow-growing broilers.The experiment started with 1,728 one-day-old slow-growing male broilers (Hubbard JA757). Nine dietary treatments were used, each replicated eight times. One group of broilers was given a control diet. The following BSF larvae products were investigated: live larvae, a combination of BSF larvae meal and oil mimicking the nutritional composition of the live larvae, and BSF larvae meal and oil separately. All insect products were tested at two inclusion levels. All diet programs were nutritionally comparable (isoenergetic and based on balanced levels of digestible essential amino acids). During the seven-week trial, several performance parameters and carcass characteristics were measured.The results show that comparable or better broiler performance was achieved with the inclusion of BSF larvae products in the diets compared to the control. Based on the feed conversion ratio (FCR), the unprocessed larvae product and the highest inclusion level led to the most favorable results. Carcass characteristics remained unchanged when BSF larvae products were used in the diets compared to the control group, indicating favorable production output. The BSF larvae products investigated seem suitable feed ingredients for broilers at the current levels tested, generating performance benefits.

Effects of black soldier fly larvae meal on production performance, meat quality, antioxidant capacity and serum biochemical indices of squabs

Abstract The aim of the study was to evaluate the effects of dietary black soldier fly larvae meal (BSFLM) on production performance, meat quality (including sensory quality, muscle fiber histological characteristics, chemical composition, and antioxidant capacity of muscle), and serum biochemical indices of 28-day-old squabs, to provide a good reference for the potential use of BSFLM as a functional feed supplement in pigeon production. A total of 192 1-day-old squabs and 96 pairs of 7-month-old breeding pigeons with the same egg production were stochastically divided into 4 groups with 6 paired replicates. Each pair of breeding pigeon with two squabs. The pigeons were fed the diets supplemented with 0 (control group), 0.5%, 1.0%, and 1.5% BSFLM, respectively. The experiment lasted for 28 days. Dietary BSFLM supplementation increased the growth performance, total antioxidant capacity (T-AOC), serum levels of glutathione peroxidase (GHS-PX), total superoxide dismutase (T-SOD), and glucose (GLU), and reduced the shear force, serum contents of triglyceride, cholesterol, low-density lipoprotein, and activities of alanine aminotransferase, aspartate aminotransferase and alkaline phosphatase. Moreover, it improved the meat color, muscle fiber histological characteristics, and fatty acids profile. However, no significant effects were observed on the slaughter performance, pH value, the water-loss, chemical composition, and amino acids profile. In conclusion, dietary BSFLM may improve the growth performance, meat quality, muscle antioxidant capacity, and health status of squabs. The best effects were observed for the 1.0% BSFLM diet.

Dietary replacement of soybean meal with black soldier fly larvae meal in juvenile Labeo rohita and Catla catla: Effects on growth, nutritional quality, oxidative stress biomarkers and disease resistance.

This experiment aimed to investigate the effects of partial substitution of crude protein from soybean meal (SBM) with black soldier fly (Hermetia illucens) larvae meal (BSFLM) in juvenile rohu (Labeo rohita) and catla (Catla catla). Four isonitrogenous diets (23% crude protein) were formulated to replace 0% (T0), 40% (T40), 80% (T80) and 100% (T100) crude protein from SBM with BSFLM. Triplicate groups of each species (10 fish per replicate) were fed in an eight week growth experiment. After final sampling (n = 20 fish per dietary group), the remaining fish were exposed to bacterial (Staphylococcus aureus) challenge (0.80 CFU/ml) for 15 days. Rohu fed with BSFLM substituted diets showed significantly higher growth and feed conversion ratio as compared to those in T0. Catla fed with BSFLM substituted diets showed slightly higher growth indices. The growth response of rohu to BSFLM substitution was better than that noted in catla in all groups. The chemical composition, amino acids and fatty acids profile, haematological and biochemical parameters, levels of liver function enzymes measured in T0, T40, T80 and T100 were similar between four dietary groups in both species. However, the maximum value of cholesterol and triglycerides were noted in T100 both in catla and rohu. The values of lauric acid, α-linolenic acid, decosahexanoic acid, n3:n6 fatty acids ratio progressively increased with dietary increase of BSFLM in both species. At end of the growth experiment, the levels of catalase, superoxide dismutase and lysozyme increased linearly with the inclusion of BSFLM in both species while malondialdehyde showed similar values between different groups. However, catalase, and superoxide dismutase increased (T0<T40<T80<T100) in both rohu and catla after exposure to bacterial challenge while malondialdehyde remained almost the same. These biomarkers indicate that substitution of SBM with BSFLM up to 100% improved disease resistance in both species against gram-positive bacteria.

Assessment of hydrolysis of partially defatted black soldier fly larvae meal in diets for Nile tilapia Oreochromis niloticus

The chitin content of black soldier fly (Hermetia illucens) larvae meal (BSFM) is known to negatively affect its digestibility by fish. Nile tilapia (Oreochromis niloticus) tolerates well BSFM in the diet. However, chemical hydrolysis of dietary BSFM has not previously been attempted for this species. In this study, based upon a low-fishmeal control diet (40% crude protein and 9% crude fat), three levels of dietary protein, 25%, 50%, and 75%, were replaced by partially defatted BSFM, subjected or not to a prior hydrolysis treatment with formic acid and fed to Nile tilapia juveniles (initial body weight: 0.26 ± 0.00 g). The hydrolysis treatment did not modify greatly the proximate and amino acid composition of the diets, nor did it improve their in vivo apparent digestibility coefficients of dry matter or crude protein. However, it significantly increased the contents of arginine, taurine, and tyrosine, and significantly reduced the contents of methionine, valine, aspartic acid, and glutamic acid in muscle tissue of Nile tilapia. The hydrolysis treatment also decreased fish growth significantly. In contrast, for diets not containing hydrolyzed BSFM, not only did fish fed all three levels of protein replacement grow satisfactorily, but the diets with the levels of replacement of 50% and 75%, with final weights of 23.04 and 23.11 g, respectively, elicited superior fish performance, as compared to the diet with 25% replacement (final weight of 20.09 g). In addition, all three protein replacement diets produced significantly greater growth than the control diet (final weight of 17.72 g). The actual levels of inclusion of BSFM were, respectively, 14.11%, 28.21% and 42.33% of diet, the latter being the highest inclusion level of BSFM reported to date for successful growth of Nile Tilapia.

Use of black soldier fly (Hermetia illucens) larvae meal in diets for gilthead seabream juveniles: Effects on growth-related gene expression, intermediary metabolism, digestive enzymes, and gut microbiota modulation

A study was conducted to evaluate the effects of dietary inclusion of defatted Hermetia illucens larvae meal (HM) on the expression of growth-related genes, plasma metabolites, activity of intermediary metabolism enzymes, and gut microbiota modulation in gilthead seabream (Sparus aurata) juveniles. Four experimental diets were formulated (43% crude protein, 18% crude lipids) with increasing levels of defatted HM: 0 (HM0), 15 (HM15), 30 (HM30), and 45% (HM45) replacing fishmeal (included at 34% in the control diet) at 0, 22, 60, and 100%, respectively. Fish were fed these diets for 67 days. At the end of the trial, the expression of muscle growth hormone receptors (ghr1 and ghr2), insulin-like growth factors (igf1 and igf2), cathepsins (cts-a and cts-b), and myogenic determination factor 1 (myod1) were not affected, while a downregulation of myogenic determination factor 2 (myod2) and upregulation of myostatin (mstn) was observed with HM inclusion. Plasma metabolites profile was unaffected by diet composition, except for a linear decrease trend in total lipids. A linear increase of liver alanine aminotransferase (ALT) and glutamate dehydrogenase (GDH) activity and a linear decrease of glucose 6-phosphate dehydrogenase (G6PDH), malic enzyme (ME), and (FAS) activity were observed with HM inclusion. The activity of β-hydroxy acyl-CoA dehydrogenase (HOAD) followed a quadratic trend, being higher in fish fed with diet HM15 than in the control. Likewise, amylase, trypsin, and chymotrypsin activity were higher in the posterior intestine of fish fed with diet HM15. Digesta of fish fed the HM-containing diets showed an increase in the number of operational taxonomic units, microbial richness, and diversity. Conversely, a reduction in these indexes was observed in the mucosa. Among the identified bacteria, Firmicutes represented the predominant phyla. The inclusion of HM increased the abundance of Oceanobacillus, Lederbergia, Bacillus, and Corynebacterium in the digesta while Lactobacillus and Caldalkalibacillus abundance was reduced. Overall, total FM replacement with defatted HM had no major effects on plasma metabolites and muscle growth-related genes but induced a few differences in intermediary metabolism and digestive enzymes activity. HM inclusion improved gut digesta microbiota richness and diversity, promoting the growth of potential beneficial bacteria.

Dietary replacement of soybean meal with black soldier fly larvae meal improves growth and disease resistance in juvenile Pangasius bocourti

Abstract This eight week long experiment was performed to study the effects of substitution of crude protein from soybean meal (SBM) with non-defatted black soldier fly (Hermetia illucens) larvae meal (BSFLM) on growth, nutritional quality, haematology, biochemistry, oxidative stress biomarkers, and bacterial disease resistance in juvenile basa (Pangasius bocourti). Four isonitrogenous and isolipidic diets (30% crude protein) were formulated to replace 0% (T0), 40% (T40), 80% (T80) and 100% (T100) of crude protein from SBM with BSFLM. Fingerlings (initial weight = 18.00 ± 1.25 g, n = 135) were stocked in aquaria. At end of the growth experiment, fifteen fish from each group were exposed to bacterial (Staphylococcus aureus) challenge (0.80 CFU/ml) for fifteen days. Fish in BSFLM substituted groups showed significantly higher growth and condition as compared to those in T0. Inclusion of BSFLM did not affect the chemical composition, profile of amino acids, and fatty acids in fish. However, the levels of lauric acid, linoleic acid, α-linolenic acid, decosahexanoic acid, and eicosapentanoic acid increased in BSFLM fed fish. The concentration of catalase, superoxide dismutase and lysozyme increased with addition of BSFLM in diet at end of the growth experiment. These oxidative stress biomarkers indicate that replacement of SBM with BSFLM up to 80% improved the growth and disease resistance in basa against gram-positive bacteria. BSFLM can be a future alternative protein source for commercial production of aquafeed for this species.

Effects of partial replacement of fish meal with black soldier fly (Hermetia illucens) larvae meal on growth performance, lipid metabolism and hepatointestinal health of juvenile golden pompano (Trachinotus ovatus)

This experiment was conducted to investigate the effects of partial replacement of fish meal with black soldier fly larvae (BSFL) meal on growth performance, body and muscle nutrients, lipid metabolism, intestinal morphology and microbiota of juvenile golden pompano (Trachinotus ovatus). Three isolipidic (12.40 ± 0.29%) and isoproteinic (42.98 ± 0.02%) experimental diets were formulated to feed golden pompano by replacing 0% (BSFL0), 25% (BSFL25) and 50% (BSFL50) of fish meal with BSFL meal. The experiment lasted for a total of 8 weeks. The results showed that compared with BSFL0, BSFL25 could significantly increase feed intake of golden pompano (P < 0.05). However, BSFL50 significantly reduced growth performance (P < 0.05). The hepatosomatic index, body and muscle crude fat in BSFL25 and BSFL50 decreased. BSFL25 could significantly reduce the activity of fatty acid synthase (FAS) and significantly enhance the activity of lipase (LPS) (P < 0.05). Both BSFL25 and BSFL50 could significantly reduce the number and volume of lipid droplets in the liver, but BSFL50 could damage the intestinal morphology and shorten the intestinal villi. Compared with BSFL0, the richness (Chao1, ACE, Sobs) and diversity (Shannon and Simpson) of intestinal microbiota in BSFL25 and BSFL50 were increased, and the abundance of Proteobacteria, Actinobacteria and Bacteroidetes was increased. In conclusion, the replacement of 25% fish meal in the feed by BSFL meal improved the food intake, lipid deposition in the liver, and intestinal microbiota balance of golden pompano, and had no harmful effects on growth and intestinal health. However, when the substitution level reached 50%, it would have a negative impact on growth and intestinal health.

Effects of partially defatted larvae meal of Black Soldier Fly (Hermetia illucens) on caecal microbiota and volatile compounds of Muscovy ducks (Cairina moschata domestica)

The present study explored the effects of substituting maize gluten meal with increasing levels of partially defatted black soldier fly larvae meal (BSFLM) in Muscovy ducks’ diets on their caecal microbiota and organic volatile compounds. The ducks were divided into four groups, each receiving a diet containing 0%, 3%, 6%, or 9% BSFLM (HI0, HI3, HI6, and HI9, respectively). At slaughter (50 days of age), caecal samples were collected and analysed. The alpha diversity indexes were lower in the HI9 than in the HI0 and HI3 treatments that did not differ between them. Bacteroidetes in the HI0 and Firmicutes in the HI6 treatment showed a higher abundance than in the HI9 treatment. Faecalibacterium and Megamonas were more abundant in the HI6 than in the HI9 treatment. Abundance of Clostridium and unclassified Coriobacteriaceae were higher and lower, respectively, in the HI9 than in the HI0 treatment. Canonical discriminant analysis revealed that Faecalibacterium, unclassified Victivallaceae and Megamonas in relation to Ruminococcus would separate the HI6 and HI9 treatments, while unclassified Coriobacteriaceae in relation to Streptococcus and Faecalibacterium would distinguish the HI0 and HI3 from the HI6 and HI9 treatments. Eleven volatile compounds were more abundant HI9 than in the HI6 treatment. Five of them were negatively correlated with Faecalibacterium and two with Megamonas. These findings indicate that diets with 6% and 9% BSFLM alter the caecal microbiota in Muscovy ducks, while a diet with 3% BSFLM has no effect. The distinct abundance of several volatile compounds in the 6% and 9% BSFLM treatments suggests a relationship between their characteristic microbiota profile and those compounds that warrants further investigation.