Hermetia Illucens Larvae Meal Research Articles

Metabolomic Effects of the Dietary Inclusion of Hermetia illucens Larva Meal in Tilapia.

Black soldier fly (Hermetia illucens) larvae meal have been used as feed protein supplements in fish feed, but few researches have investigated the metabolomic effects of Hermetia illucens larvae meal supplements. Therefore, the metabolic effects on Nile tilapia were investigated by replacing 5%, 10%, and 20% of the dietary soybean meal in the basal diet with Hermetia illucens larvae meal, respectively. This study shows that 20% H. illucens larvae meal feed could promote tilapia average daily gain of upto 5.03 ± 0.18 g (mean ± SEM). It was found that the tricarboxylic acid cycle efficiency was improved by activating the enzymes of mitochondrial isocitrate dehydrogenase, NAD-malate dehydrogenase, succinate dehydrogenase, pyruvate dehydrogenase, and α-ketoglutarate dehydrogenase, which then increased the output of ATP and NADH. Furthermore, amino acid and protein biosynthesis was boosted by enhanced glutamine synthetase and glutamate synthase. In particular, GSH increased with increased H. illucens larvae meal. Unsaturated fatty acid biosynthesis was stimulated by higher levels of fatty acid synthase and acetyl CoA carboxylase. Additionally, there was no significant change in lipase levels. Thus, the higher acetyl Co-A content was primarily involved in fatty acid biosynthesis and energy metabolism. Flavor substances, such as nonanal and 2-methyl-3-furanthiol, also accumulated with the addition of H. illucens larvae meal, which increased the umami taste and meat flavor. Additionally, the flavor of tilapia was improved owing to a decrease in trimethylamine content, which causes an earthy and fishy taste. This study uncovers a previously unknown metabolic effect of dietary H. illucens larvae meal on Nile tilapia.

Chemical Composition and Fatty Acid Profile of the Pectoralis major Muscle in Broiler Chickens Fed Diets with Full-Fat Black Soldier Fly (Hermetia illucens) Larvae Meal.

Simple SummaryInsect meal (processed insect protein) can effectively cater to the growing demand for protein sources in animal diets. However, insect meals have to be thoroughly analyzed before they can be incorporated into the diets of monogastric animals (such as poultry) because animal nutrition is directly correlated with the quality (including chemical composition) of meat, which was confirmed by the present study. Further research is needed to determine the efficacy of full-fat Hermetia illucens (HI) larvae meal in broiler chicken nutrition. Lower dietary inclusion levels of insect meal than those analyzed in this study, and insect meal with a modified fatty acid profile should be investigated to optimize the nutritional value and health benefits of poultry meat.The aim of this study was to determine the effect of full-fat Hermetia illucens (HI) larvae meal used as a substitute for 50%, 75% and 100% of soybean meal (SBM) in diets fed to male Ross 308 broiler chickens on the proximate chemical composition and fatty acid profile of the Pectoralis major (PM) muscle. The muscles of chickens fed HI larvae meal were characterized by a higher (p < 0.05) total concentration of pigments and lower (p < 0.05) ash content. At the lowest dietary inclusion rate (50%) of HI larvae meal, the PM muscle had a lower (p < 0.05) content of fat and collagen, compared with the remaining treatments. An analysis of the fatty acid profile of the PM muscle revealed that the total concentrations of saturated fatty acids increased (p < 0.05) and the total concentrations of polyunsaturated fatty acids decreased (p < 0.05) with increasing inclusion levels of HI larvae meal. The changes in the fatty acid profile of muscles in birds receiving HI larvae meal led to a decrease in the nutritional value of fat. The present findings indicate that the ≥50% inclusion rate of full-fat HI larvae meal as a protein source alternative to SBM in broiler chicken diets is too high due to its negative effect on the fatty acid profile of meat.

Evaluation of microwave-dried black soldier fly (Hermetia illucens) larvae meal as a dietary protein source in broiler chicken diets

Here, the effect of microwave-dried black soldier fly (Hermetia illucens) larvae meal (HILM) as a dietary protein source on the growth performance and health of broilers was evaluated. A total of 126 male broilers were randomly allocated to three treatments (six replicates of seven birds per group): control diet (CON) of corn and soybean meal and two experimental diets in which soybean meal was replaced with 25% (25HILM) or 50% (50HILM) HILM. The broilers were slaughtered at 35 d to determine the apparent ileal digestibility (AID), volatile fatty acid (VFA) profiles, and length and weight of the small intestine. Blood samples were collected from 36 randomly selected birds (12 broilers per treatment) to determine serum parameters and haematological traits. Average daily gain, feed intake, and AID of protein were decreased (P&lt;0.05) in the 50HILM group compared with those in the CON group. Dietary HILM increased (P&lt;0.05) the relative length of the entire digestive tract and total VFAs in the caecal digesta. Serum low-density lipoprotein cholesterol was the lowest (P&lt;0.01), but the triglyceride levels were the highest (P&lt;0.05) in the 50HILM group. The serum phosphorus level was lower in both HILM diet-fed groups (P&lt;0.01), whereas the creatine phosphokinase level was lower in the 50HILM group than in the CON group. In contrast, the 50HILM group showed higher (P&lt;0.05) monocyte and red blood cell distribution width-standard deviation. In conclusion, dietary microwave-dried HILM positively influenced the VFA and cholesterol levels; however, growth performance was negatively affected by malnutrition caused by low protein digestibility in the 50HILM group. Microwave-dried HILM is a valuable ingredient for broiler diets, with up to 25% substitution showing no detrimental effects on growth performance and health. Further studies are needed to improve HILM digestibility.

Black Soldier Fly (Hermetia illucens) Larvae Meal Modulates Intestinal Morphology and Microbiota in Xuefeng Black-Bone Chickens.

The addition of Hermetia illucens larvae meal (HILM) to the feed could contribute to particular antimicrobial and intestinal health in animal husbandry. This study was conducted to investigate the effects of HILM on intestinal morphology and microbial diversity in different intestinal segments of Xuefeng black-bone chickens. All of 432 birds (45 weeks old) were randomly assigned to four equal groups with six replicates and 18 hens in each replicate: (A) basal diet, (B) basal diet with 1% HILM, (C) basal diet with 3% HILM, and (D) basal diet with 5% HILM. The results showed that, compared with the basal diet group, the HILM supplement significantly increased the abundance-based coverage estimator (ACE) and Chao index in cecum (p < 0.05). Diet with 1% HILM significantly increased the villus height (VH) of the duodenum (p < 0.05) and cecum microbial diversity as represented by the Simpson index (p < 0.05). In particular, 1% HILM displayed a markedly increase in the genus unclassified Bacteroidales (cecum, p < 0.05). A basal diet with 3% HILM markedly increased the beneficial genus Romboutsia (jejunum, p < 0.05). Also, principal component analysis (PCA) cluster analysis showed that 3% of HILM was more individual than other groups (p < 0.05). However, 5% HILM decreased the VH and the ratio of villus height to crypt depth (VH/CD) of the jejunum and increased beneficial bacteria such as Staphylococcus (p < 0.05), which was regarded as pathogenetic genera. In conclusion, we found that HILM improved intestinal morphology and increased microbiological diversity and species abundance. Together, dietary supplementation of 1 or 3% HILM might benefit the intestinal morphology and intestinal microbiota of Xuefeng black-bone chicken. However, the addition of 5% HILM could decrease VH and the ratio of VH/CD of the jejunum and increased pathogenetic genera. HILM was an excellent protein substitute for Xuefeng black-bone chickens, which could meet the nutritional requirements under the condition of less feed. These results provide information for HILM meal as an alternative source of soybean meal in Xuefeng black-bone chickens’ feed.

Effect of dietary black soldier fly larvae meal on fatty acid composition of lipids and sn-2 position of triglycerides of marketable size gilthead sea bream fillets

Insects are an alternative protein source recently adopted in aquacultured carnivorous species. However, the replacement of marine ingredients with insect meal might cut down the n−3 polyunsaturated fatty acid (PUFA) of fish fillet, a fraction of great interest for human nutrition. Recently, it has been shown that different animal species and the human species better absorb the dietary fatty acids esterified in the sn-2 position of the triglyceride (TG) than those contained in the sn-1 and sn-3 positions. Hence, the present paper aimed to evaluate in which extent replacing fishmeal with insect meal could alter not only the fillet fatty acid (FA) profile, but even the FA distribution inside the TGs. Specifically, three-hundred and sixty gilthead sea bream (Sparus aurata L.) were randomly divided into four groups with three replicates each. The fish were fed for 120 days four isoenergetic, isolipidic and isoproteic diets where fishmeal was substituted by Hermetia illucens (HI) larvae meal. The inclusion levels were 0% (HI0), 9.2% (HI9), 18.4% (HI18) and 27.6% (HI27), corresponding to 0, 25, 50 and 75% of fishmeal substitution, respectively. At the end of the trial, 10 fish per group were analyzed for marketable traits, fillet color values and lipid composition. Dietary intervention did not affect any of the considered marketable traits and the fillet color. Major changes were observed in the FA profile of the fillet lipids. The fillets from fish fed HI18 and HI27 contained the highest amount of saturated fatty acids while their n-3 PUFA were significantly reduced in comparison with HI0 and HI9. Analogous variations were observed in the FA composition of the TG fraction. On the contrary, dietary HI did not reduce the overall n-3 PUFA positioned in the sn-2 of TG, nor eicosapentaenoic acid (EPA) percentage. In conclusion, dietary HI inclusion did not substantially modify the presence of important fatty acids for human nutrition (i.e., EPA and DHA) in the sn-2 position of the fillet triglycerides, increasing the chances to be better assimilated and absorbed by humans.

Effect of Graded Substitution of Soybean Meal by Hermetia illucens Larvae Meal on Animal Performance, Apparent Ileal Digestibility, Gut Histology and Microbial Metabolites of Broilers.

Simple SummarySoybean meal (SBM) constitutes the major protein source in European poultry production, meaning a high dependency on imports and a reduced sustainability of produced meat. To cope with this challenge, alternative protein sources are needed, and insects are considered as a novel, alternative protein source in broiler nutrition. The objective of the present study was to evaluate the replacement of 15 or 30% of crude protein (CP) from SBM with Hermetia illucens (HI) defatted larvae meal CP regarding broiler performance, carcass traits, apparent ileal CP and amino acid (AA) digestibility, intestinal morphology, and microbial metabolites. The data showed impaired performance and lower ileal CP and AA digestibility with 30% substitution of CP from SBM with HI larvae meal CP. However, lower substitution, i.e., 15% substitution of SBM CP with HI larvae meal, for broiler feeds seems possible without impairment in animal performance and digestion variables and should be pursued in the future.The usage of insects as an alternative protein source for broiler feeds may help to reduce the dependency on soybean meal (SBM) imports. Therefore, the present study aimed to evaluate the replacement of 15 (SL15) or 30% (SL30) of crude protein (CP) from SBM with Hermetia illucens (HI) defatted larvae meal regarding broiler performance, carcass traits, apparent ileal digestibility, intestinal morphology, and microbial metabolites. Concerning the performance, body weight was similar for the control (CON) and SL15, but lower for SL30 during all feeding phases. In addition, average daily feed intake was higher in SL15 and SL30 compared to CON in the starter phase, but this effect vanished during grower and finisher phase. The apparent ileal digestibility decreased for CP and some amino acids with increasing HI larvae meal in the diet. No or marginal alterations were observed for the intestinal morphometry as well as cecal microbial metabolites. In conclusion, partial replacement of 15% SBM CP with HI larvae meal in broiler diets without impairing animal performance or health seems possible. The growth suppression with 30% CP substitution may be caused by reduced apparent ileal digestibility but could not be clearly associated with adverse effects of hindgut fermentation or altered gut morphology.

Effects of Dietary Inclusion Level of Microwave-Dried and Press-Defatted Black Soldier Fly (Hermetia illucens) Larvae Meal on Productive Performance, Cecal Volatile Fatty Acid Profile, and Egg Quality in Laying Hens.

Simple SummaryThe microwave drying method is convenient in terms of time efficiency, space, and low operational cost compared with the conventional air-drying method. For the same reasons, the microwave drying method has the potential for manufacturing insect meals that could be an alternative protein source in poultry. Therefore, we evaluated the productive performance, cecal volatile fatty acid (FA) profile, and egg quality in laying hens fed on microwave-dried Hermetia illucens larvae meal (HILM) at two different substitution levels (2% and 4%) of soybean meal. Similar productive performance with no negative effects on the nutritional and physical quality of eggs was observed from the study, indicating that microwave-dried HILM can be a potential ingredient in the diets of laying hens. However, further research is needed in improving the manufacturing process for better bioavailability of HILM and improved FA quality of eggs.Black soldier fly (Hermetia illucens) larvae meal (HILM) is a promising alternative to soybean meal (SBM). However, little information is available on the effect of microwave-dried HILM as a dietary protein source in the diets of laying hens. We studied the effect of dietary inclusion level of microwave-dried HILM on productive performance, cecal volatile fatty acid profile, egg quality, overall fatty acid profile, and heavy metal residues of the egg in laying hens. A total of 144 laying hens (25-week-old) were randomly assigned to three dietary groups (eight replicates and six birds/cage): a control diet, and two experimental diets in which SBM was replaced with 2% HILM (2HILM) and 4% HILM (4HILM). The laying hens that fed the HILM showed satisfactory results in productive performance and egg quality. Branched-chain fatty acid levels increased linearly (p < 0.001) with dietary treatment in the cecal digesta. Total monounsaturated fatty acid increased linearly (p < 0.01), while total polyunsaturated fatty acid decreased linearly (p < 0.01) in the eggs by dietary treatments. Heavy metals, magnesium, zinc, and aluminum were increased linearly with dietary treatment; however, undesirable heavy metals were under permissible levels. Thus, microwave-dried HILM could be a possible alternative to SBM in the diets of laying hens; however, improvements in fatty acid profile are needed.

Effects of Dietary Inclusion Level of Microwave-Dried and Press-Defatted Black Soldier Fly (Hermetia illucens) Larvae Meal on Carcass Traits and Meat Quality in Broilers.

Simple SummaryInsects are a potential source of protein for broiler diets because of the high price and limited supply of soybean. Black soldier fly (Hermetia illucens; HI) larvae are promising candidates as an alternative protein source to soybean meal; a microwave drying method is a convenient approach for producing HI larvae meal (HILM), as it is time- and energy-efficient. However, whether microwave-dried HILM is an appropriate protein source for producing healthy chickens for consumers has not been evaluated. Therefore, we examined the effect of 0, 25, and 50% dietary replacement of soybean meal with HILM on carcass traits, meat quality, and safety. We observed satisfactory results for the meat quality and fatty acid composition without detrimental effects on undesirable heavy metal residues in the meat. However, the carcass weight was reduced in 50% HILM-substituted diets, suggesting that a low level of HILM is beneficial. Microwave-dried HILM is a promising ingredient for broiler diets. However, further research is needed to overcome the lowering of the carcass weight in terms of utilization efficiency by improving the manufacturing process.Limited information is available regarding the use of microwave-dried Hermetia illucens larvae meal (HILM) as a dietary protein source for broiler diets. Therefore, we investigated the effects of microwave-dried HILM on carcass traits, meat quality, fatty acid (FA) profiles of abdominal fat and meat, and heavy metal residues of the meat in broilers. A total of 126 male broilers were randomly assigned to three dietary treatment groups (6 replicates and 7 birds/pen): a control diet and two experimental diets in which soybean meal was replaced with 25 or 50% HILM. The broilers were slaughtered at 35 days; the carcasses were weighed, and breast and leg meats were excised from 12 birds per treatment (2 birds/pen) for meat analysis. The breast meat quality and proximate composition showed satisfactory results. For the higher HILM diet, the content of saturated FA in the abdominal fat was increased and that of polyunsaturated FA was decreased (p < 0.001); the FA profile of leg meat did not significantly differ between groups. The concentrations of undesirable heavy metals in the HILM and leg meat were below permissible levels. However, the carcass weight was decreased (p < 0.001) in the 50% HILM group. Microwave-dried HILM is a potential ingredient for broiler diets, with up to 25% substitution showing no detrimental effects on carcass traits, meat quality, FA profiles, and heavy metal residues in the meat.

Supplementation of tuna hydrolysate and insect larvae improves fishmeal replacement efficacy of poultry by-product in Lates calcarifer (Bloch, 1790) juveniles

The effects of feeding different levels of poultry by-product meal (PBM) replacing fishmeal (FM) protein, supplemented with tuna hydrolysate (TH) and Hermetia illucens (HI) larvae, on the growth, fillet quality, histological traits, immune status, oxidative biomarker levels and gut microbiota of juvenile barramundi, Lates calcarifer were investigated for six weeks. Barramundi were fed four isonitrogenous and isolipidic diets in which a FM based diet was used as the Control diet (Diet1) and compared with other non-FM diets containing 80%, 85% and 90% PBM along with the concurrent supplementation of 5% and/or 10% TH and HI larvae meal. These treatment diets were designated as 80PBM10TH+10HI (Diet2), 85PBM5TH+10HI (Diet3) and 90PBM5TH+5HI (Diet4). The growth and condition factor of fish fed 80PBM10TH+10HI and 85PBM5TH+10HI were significantly higher than the Control. Total saturated, monounsaturated and polyunsaturated fatty acid retention in the fish muscle increased in fish fed PBM-based diets, supplemented with TH and HI larvae meal, with no adverse effect on post-harvest characteristics such as texture and colour of fish fillets. Improvement in serum total bilirubin and total protein content was found in all fish fed TH and HI larvae supplemented PBM. Similarly, immune response showed a significant increase in fish fed non-FM test diets than the Control. In the distal intestine, supplementation of any quantities of TH and HI larvae to PBM led to an increase in the microvilli density and neutral mucins while the number of goblet cells in the skin were unchanged. Liver, kidney, and spleen histology demonstrated a normal structure with no obvious changes in response to all test diets. Bacterial diversity increased in fish fed Diets 2 and 3 with a high abundance of Proteobacteria in Diets 1 and 4 and Firmicutes in Diets 2 and 3. The fish on test diets showed a lower abundance of genus Vibrio. Fish fed TH and HI larvae supplemented PBM diets showed lower infection rate to V. harveyi than the Control. Collectively, concurrent supplementation of TH and HI larvae could improve the quality of PBM diets with positive effects on growth, fillet quality, intestinal health, immunity, and disease resistance.

The effect of dietary full-fat Hermetia illucens larvae meal on gut physiology and growth performance in young turkeys

The aim of this study was to determine the efficacy of full-fat Hermetia illucens larvae meal (HM) as a protein source in diets for the youngest turkey poults, based on growth performance and parameters of intestinal function, i.e. immune status and fermentation processes in the gut. The experiment was carried on 432 one-day-old male Hybrid Converter turkeys. The birds were randomly divided into four dietary treatment groups, with twelve replicates of nine birds each. During a four-week feeding period, the HM content of turkey diets was 50, 100 and 150 g/kg in groups HM50, HM100 and HM150, respectively. The highest HM content in the experimental diet HM150, limited by high crude fat content, replaced 1/3 of soybean meal (SBM) (295 vs. 429 g/kg) in the control diet HM0. The inclusion of dietary HM resulted in a linear increase in the dry matter (DM) content and viscosity of small intestinal contents. The highest inclusion rate of HM did not affect IgA levels, but it increased IgY levels in the small intestinal tissue compared with the control treatment. At the same time, dietary HM exerted anti-inflammatory effect by decreasing TNFα and increasing IL-6 levels in small intestinal tissue (linear and quadratic response, respectively). The dietary inclusion of HM increased the activity of selected microbial enzymes (α-galactosidase, β-glucosidase and β-glucuronidase) and butyric acid concentration in the cecal digesta. Increasing inclusion levels of HM did not affect the final body weight (BW) or body weight gain (BWG) of birds, but induced a linear decrease in the feed conversion ratio (FCR). The results of this study indicate that HM can be included in diets for young turkeys at up to 150 g/kg without compromising the immune status or growth performance of birds, intestinal development and function.

Supplementation of Hermetia illucens Larvae in Poultry By-Product Meal-Based Barramundi, Lates calcarifer Diets Improves Adipocyte Cell Size, Skin Barrier Functions, and Immune Responses.

A 6-week feeding trial was performed to examine the effects of supplementing Hermetia illucens (HI) larvae meal when fishmeal (FM) was replaced with poultry by-product meal (PBM) in juvenile barramundi, Lates calcarifer diet. The effect was evaluated in terms of barramundi growth, filet quality, internal tissue structure, serum biochemistry, skin neutral mucins, immune response, and resistance to Vibrio harveyi. Three isonitrogenous (48% crude protein) and isolipidic (18% crude lipid) diets: an FM-based diet (control) and two diets containing 60 and 75% of PBM supplemented with 10% HI larvae (60PBM + HI and 75PBM + HI) were formulated. A total of 225 barramundi, with an average weight of 15.87 ± 0.14 g, were randomly distributed into nine tanks, each holding 25 fish. There were no significant effects of test diets on growth, but feeding HI-supplemented PBM diets significantly increased the survival rate. A significantly reduced intraperitoneal fat index in HI-supplemented-PBM-fed fish was correlated to a decreased size of peritoneal adipocytes. The observation of no histopathological alteration of the liver in the HI-supplemented-PBM-fed fish was further supported by significant alterations in serum biochemistry, in particular, a decreasing tendency of alanine transaminase, glutamate dehydrogenase, and total bilirubin. A 14-day challenge with V. harveyi indicated that HI-supplemented PBM diets reduced the infection rate in barramundi. After 24 h of infection, increased serum (lysozyme) and skin barrier functions, down-regulation of interleukin-1beta, and upregulation of interleukin-10 were found in HI-supplemented-PBM-fed fish.

Effects of different levels of Hermetia illucens larvae meal on performance, egg quality, yolk fatty acid composition and oxidative status of laying hens

To investigate the supplemental effects of Hermetia illucens larvae meal (HILM) on the production, egg quality, yolk fatty acid composition, egg amino acid content, oxidative status, and immune indexes of laying hens. A total of 432 Xuefeng black-bone chickens (45-week-old) were randomly assigned to 4 treatments with 6 replicates per treatment and 18 hens in each replicate. The laying hens were fed the basal diet supplemented with 0%, 1%, 3%, and 5% HILM (CON, HILM-1, HILM-3, and HILM-5, respectively) for 56 d. The experimental diets were isonitrogenous and isoenergetic. The highest egg weight and Haugh unit were obtained with 3% HILM supplementation, but the HILM-3 or HILM-5 supplementation have negative effect on the eggshell thickness, yolk index, and albumen height during the early stage of the experiment. The HILM supplementation linearly or quadratically (p < .05) increased the C14:0, C17:0, C18:2n6c, C20:2 contents of yolk, the Glu, Val, Met, Phe, and Leu contents of egg, the T-SOD and CAT activities, and the NDV-Ab and AIV-Ab levels of plasma. With increasing supplementation of HILM in the basal diet, FCR, the C16:0 and C16:1 contents of yolk, MDA content and IL-2 level of plasma decreased both linearly or quadratically (p < .05). In conclusion, Hermetia illucens larvae meal can be a suitable alternative protein source for Xuefeng black-bone chicken. Dietary supplementation of 3% HILM in basal diets may be a feasible means of effectively increasing the production performance of laying hens, and partially enhanced hens’ antioxidant capability and immune function. HIGHLIGHTS Supplementation of 1% HILM had no effect on laying hens, and supplementation of 3% HILM increased the egg weight and Haugh unit. Supplementation of 3% HILM or 5% HILM have a negative effect on the eggshell thickness, yolk index, and albumen height during the early stage of the experiment. Supplementation of 3% HILM increased the C14:0, C17:0, and C20:2 contents of yolk, the Glu, Val, Met, Phe, and Leu contents of egg. The plasma antioxidant status and immune response improved by dietary addition of HILM at 3% levels.

Inclusion of Hermetia illucens larvae reared on fish offal to the diet of broiler quails: Effect on immunity and caecal microbial populations

Hermetia illucens (black soldier fly, BSF) larvae meal has shown to be a good protein source in monogastric animal diets, but published data regarding its immunomodulatory properties is limited. For this purpose, a study has been conducted to evaluate the effects of larvae meal on selected immune parameters and caecal bacterial counts of broiler quails. Hermetia illucens larvae were reared on two substrates (100% chicken feed, BSF-M, or 50% chicken feed + 50% fish offal, BSF-F) in order to manipulate the fatty acid profile of larvae meal by increasing the long-chain omega-3 (n-3) polyunsaturated fatty acids which are known for their immunomodulatory properties. For immunological purposes, a total of 60 birds were randomly allocated to three dietary treatment groups (n = 20/treatment): control quail diet (CON), or quail diets including 10% of BSF-F or BSF-M larvae meal. Blood was collected 27 and 37 days after the trial commenced to determine the humoral immune response, serum lysozyme concentrations, serum bactericidal activity and protein fractions of the serum. The dietary inclusion of BSF-M meal resulted in an increased secondary humoral immune response compared to the CON treatment group (P &amp;lt; 0.01). Quails in the BSF-F treatment had significantly higher serum lysozyme activity compared to quails in the CON and BSF-M treatment group. Both larvae meals significantly increased cell-mediated immunity on day 37 (P &amp;lt; 0.001) but they had no effect on serum bactericidal activity. Both larvae meal sources resulted in higher α2-globulin levels on both sampling days, whereas γ-globulin levels were significantly lower in quails with the BSF-F treatment on day 27. Dietary treatments had no significant effect on caecal bacterial counts. In conclusion, the present study showed that the larvae meal had immunostimulatory effects in quails, but the rearing substrate of larvae strongly influenced the immunostimulatory properties of the larvae meal.

Effects of Partially Defatted Hermetia illucens Meal in Rainbow Trout Diet on Hepatic Methionine Metabolism.

Simple SummaryFor sustainable aquaculture development, fish meal from the sea in aquafeed should be replaced with other sustainable materials such as insect larvae. The authors fed black soldier fly maggot meal to rainbow trout and examined the expression of three genes and two metabolites involved in turn-over of methionine that is an essential amino acid in fish. According to the increase in the maggot content in the aquafeed, gene expression was modulated to maintain an optimal level of methionine metabolites. Dietary replacement of up to 50% of fish meal with the maggot meal was acceptable, implying future development of a new aquafeed for sustainable aquaculture.This study investigated, for the first time, the effects of replacement of fishmeal (FM) with insect meal from Hermetia illucens (HI) on the transcript levels of three genes involved in methionine (Met) metabolism in rainbow trout (Oncorhynchus mykiss) liver. Two target genes—betaine-homocysteine S-methyltransferase (BHMT) and S-adenosylhomocysteine hydrolase (SAHH)—are involved in Met resynthesis and the third one—cystathionine β synthase (CBS)—is involved in net Met loss (taurine synthesis). We also investigated the levels of two Met metabolites involved in the maintenance of methyl groups and homocysteine homeostasis in the hepatic tissue: S-adenosylmethionine (SAM) and S-adenosylhomocysteine (SAH). Three diets were formulated, an FM-based diet (HI0) and two diets in which 25% (HI25) and 50% (HI50) of FM was replaced with HI larvae meal. A 78-day feeding trial involved 360 rainbow trout with 178.9 ± 9.81 g initial average weight. Dietary replacement of up to 50% of FM with HI larvae meal, without any Met supplementation, did not negatively affect rainbow trout growth parameters and hepatic Met metabolism. In particular, Met availability from the insect-based diets directly modulated the transcript levels of two out of three target genes (CBS, SAHH) to maintain an optimal level of one-carbon metabolic substrates, i.e., the SAM:SAH ratio in the hepatic tissue.

Effect of partial black soldier fly (Hermetia illucens L.) larvae meal replacement of fish meal in practical diets on the growth, digestive enzyme and related gene expression for rice field eel (Monopterus albus)

A ten-week feeding trial on Monopterus albus (initial weight 24.02 ± 0.02 g) was conducted to evaluate effects of four isonitrogenous and isoenergetic diets in which different proportions of fish meal (0, 2.5 %, 5% and 7.5 %) were substituted with Hermetia illucens (HI) larvae meal, corresponding to dietary inclusion levels of 0 (FM), 5.26 % (HI5.26), 10.52 % (HI10.52) and 15.78 % (HI15.78). Compared with FM, weight gain rate and condition factor of M. albus and gumminess and adhesiveness of its muscle tissue were significantly increased in HI5.26 and HI10.52 groups (P < 0.05); whereas feed conversion ratio was markedly decreased in HI5.26 (P < 0.05), and expression of hepatic FASD2 and ME2 was significantly upregulated in HI5.26 (P < 0.05). Compared with FM, cohesiveness of muscle was significantly decreased in HI groups, but hardness of muscle and expression of hepatic FAS were remarkably upregulated in HI groups (P < 0.05); ACC and ME1 mRNA levels were significantly upregulated in HI10.52 (P < 0.05); CPT2 mRNA levels were significantly upregulated in HI5.26 and HI15.78 (P < 0.05); PPARγ, G6PD and HSL mRNA levels were significantly upregulated in HI10.52 and HI15.78 (P < 0.05). Springiness and chewiness of muscle, activity of intestinal lipasewere, serum indexes (glutamic oxalacetic transaminase, catalase, malondialdehyde), several gut bacterial indices (shannon, chao1, ACE, OTUs abundance of proteobacterias) and abundance of hepatic PPARα mRNA in HI15.78 were remarkably lower than those in FM (P < 0.05), while content of crude lipid, gut firmicutes and hepatic Dgat2 mRNA were significantly lower than FM (P < 0.05). Results showed that HI improved growth performance and balance of gut bacteria of M. albus when supplemented at a rate below 15.78 %, but negative effects on lipid metabolism were observed when HI was supplemented at excessive levels.

Evaluation of full-fat Hermetia illucens larvae meal as a fishmeal replacement for weanling piglets: Effects on the growth performance, apparent nutrient digestibility, blood parameters and gut morphology

The present study aimed to investigate the effects of different inclusion levels of Hermetia illucens larvae meal on the growth performance, apparent nutrient digestibility, blood parameters, and gut morphology of weanling piglets. A total of 128 weanling piglets were randomly assigned to 4 dietary treatment groups. Full-fat H. illucens larvae meal was included at increasing levels (0, 1, 2, and 4 %; HI0, HI1, HI2, and HI4, respectively) in isonitrogenous and isoenergetic diets formulated for 2 feeding phases: I (from day 1–14) and II (from day 15–28). Each treatment consisted of 8 pens (replicates), with 4 pigs per pen. After 28 d of feeding, 8 piglets per treatment (n = 8) were slaughtered. Results showed that the body weight (BW) on day 14, average daily gain (ADG) from day 1–14, and the relative weight of the liver, pancreas, and small intestine had a linear increase (P < 0.05, maximum in HI2) in response to H. illucens larvae meal consumption, while the feed/gain (F/G) ratio from day 1–14 exhibited a linear and quadratic decrease (P < 0.05, minimum in HI2) in the response. Linear and quadratic decreases (P < 0.05, minimum in HI4) were detected for the crude protein and crude fat digestibility. Linear and quadratic (P < 0.05, maximum in HI2) were observed for the total protein and globulin concentrations, while a linear and quadratic (P < 0.05, minimum in HI2) effect was observed for the urea concentration. The triglyceride concentration showed a quadratic decrease (P < 0.05, minimum in HI2) in response to H. illucens larvae meal consumption. Linear and quadratic (P < 0.01) were observed for the IFN-γ (minimum in HI4) and IgA (maximum in HI2) concentrations. The HI2 diet also increased the IL-10 concentration compared with HI0 group (P < 0.05). Furthermore, the villus height in the jejunum of the piglets was higher in the HI2 group than in the HI0 group (P < 0.05). Collectively, our results indicated that feeding 2 % full-fat H. illucens larvae meal to partly replace fishmeal changed the host metabolism, immune status, and intestinal morphology of weanling piglets. These findings further increase our knowledge and provide novel information about the potential of H. illucens larvae meal as a suitable alternative fishmeal source for swing feeding.

Quality of Eggs and Albumen Technological Properties as Affected by Hermetia Illucens Larvae Meal in Hens' Diet and Hen Age.

Simple SummaryConcurrently with the actual challenges in the poultry industry, we aimed to assess the changes induced by the inclusion of an alternative protein source (partially defatted Hermetia illucens larva meal, HI) at two different levels as well as hen age on the overall egg quality and deepened their effect of albumen technological properties. This study could provide useful information for the egg supply chain in order to optimize egg utilization, as a whole or as egg products, thus preventing food losses or undesirable wastes. Specifically, based on the obtained results, the eggs laid by hens fed the highest inclusion of HI would be directed towards egg product industry due to their reduced eggshell percentage and thickness which could increase their fragility. Contrariwise, due to the impaired albumen technological properties, as foaming, found in the egg laid by 27–35 wk-old hens, they could be preferentially sold as a whole.The impact on the egg quality and the albumen technological properties were here evaluated as affected by diet and hen age (A) of 162 Hy-line Brown hens. Three isoproteic and isoenergetic diets were formulated respecting the requirements for Hy-line hens: the control diet (C) based on conventional protein sources, and other two where vegetable proteins were substituted at 25% (HI25) and 50% (HI50) by partially defatted Hermetia illucens larva meal (HI). Ten eggs collected from each group at the hen ages of 20, 27, and 35 weeks were evaluated. The eggshell percentage and thickness were significantly reduced in the HI50 eggs (11.93% and 476 µm, respectively) compared to the C (12.34%, 542 µm) and HI25 (12.54%, 516 µm). The aging lowered (p = 0.05) the protein and increased (p < 0.001) water contents of the eggs. Although the foam capacity of the HI50 albumen was halved than the C group (p < 0.05), it was unaffected by the aging. Additionally, this did not impair the volume and the textural properties of a batter (angel cake) in which it was included. On the opposite, the textural characteristics of the cake made by the oldest hens (i.e., 35 wk-old) were compromised. In conclusion, the diet and hen age differently affected egg quality and its technological properties, which could be positive to obtain eggs to destine directly to the market or to the egg industry.

276 Effects of Hermetia illucens larvae meal on growth performance, carcass traits, and meat quality in finishing pigs

Abstract Object: This study aimed to investigate the effects of Hermetia illucens larvae meal on growth performance, carcass traits, and meat quality of finishing pigs. Methods: Seventy-two crossbred (Duroc × Landrace × Large White) pigs (76.0 ± 0.52 kg) were randomly allocated to three experimental treatments, and fed the diet with supplementation of 0%, 4%, or 8% Hermetia illucens larvae meal (HILM), respectively. The experiment lasted 42 days. Results: The average daily gain (ADG) of pigs in 4% HILM group was higher, and the feed gain ratio (F/G) was lower than the control and 8% HILM group (P &amp;lt; 0.05). The loin-eye area, marbling scores, and inosine monophosphate (IMP) content of Longissimus thoracis muscle (LM) in 4% and 8% HILM group were higher than the control group (P &amp;lt; 0.05). There were no diffenences on backfat thickness, pH value, meat color, drip loss among three groups. Compared with the control, 4% HILM significantly increased the content of intramuscular fat (IMF) (P &amp;lt; 0.05). Meanwhile, the mRNA expression level of fatty acid synthase (FAS), acetyl CoA carboxylase α (ACCα), lipoprotein lipase (LPL), and MyHC-IIa in the LM was higher in 4% HILM group than that in 8% Hermetia illucens larvae meal and the control group (P &amp;lt; 0.05). The abundance of Lactobacillus, Pseudobutyrivibrio, Roseburia, Oribacterium, and Faecalibacterium was higher in 4% Hermetia illucens larvae meal group than the control group (P &amp;lt; 0.05); The abundance of Streptococcus was lower and Peptococcus was higher in 4% HILM group than 8% HILM group. Conclusion: HILM can be used as an effective feed ingredient in finishing pig’ diet up to 4% level, which was beneficial for the growth performance, carcass trait, and meat quality of pigs, and the underlying mechanism maybe due to the altered lipogenic potential, myofiber characteristics and the microbial composition regulated by HILM.

First insights on Black Soldier Fly (Hermetia illucens L.) larvae meal dietary administration in Siberian sturgeon (Acipenser baerii Brandt) juveniles

The Hermetia illucens (L.) larvae meal (HIM) has been tested on different fish species but its use on Siberian sturgeon has not been investigated yet. The aim of this study was to evaluate the effects of fish meal (FM) substitution with a highly defatted HIM on growth performance, biometric and morphometric indices, apparent digestibility of diets, whole body proximate and fatty acid compositions of Acipenser baerii (Brandt) juveniles. Five experimental groups were fed with a FM-based diet without HIM (HIM0), three diets with 25% (HIM25), 50% (HIM50) and 100% (HIM100) of FM substitution with HIM, or a vegetable protein based diet (VEG) without HIM. The feeding trial lasted 118 days and 4 replicates per diet were used. The HIM100 diet was refused by the fish and therefore this experimental group was excluded from statistical evaluation. Moreover, a decrease in feed consumption was recorded with the increase of HIM inclusion. The HIM50 diet negatively affected the growth performance of the fish. The somatic indices were not affected by treatment. Increasing levels of HIM showed increases of dry matter and ether extract contents in the whole body. Compared to HIM0, HIM diets caused modification in lauric acid (up to 65-fold increase) and total saturated fatty acids (up to 1.4-fold increase) contents in the fish whole body. The apparent digestibility coefficients of dry matter, crude protein and gross energy were the highest for the VEG diet (77.0%, 90.4% and 85.8%, respectively). HIM25 and HIM50 showed lower apparent digestibility coefficients of crude protein (86.5% and 86.6%, respectively) when compared to HIM0 (88.5%). Overall, this study showed that it is possible to replace up to 25% of FM with HIM in the diet of Siberian sturgeons (equal to 18.5% HIM inclusion level) without affecting the growth performance, condition factor, biometric and morphometric indices, and whole body proximate composition of the fish. The fatty acid composition of the sturgeons’ whole body was significantly modified already at 18.5% dietary HIM inclusion level.

Intestinal Morphometry, Enzymatic and Microbial Activity in Laying Hens Fed Different Levels of a Hermetia illucens Larvae Meal and Toxic Elements Content of the Insect Meal and Diets

Simple SummaryRecently, several studies have focused on the use of insect larvae meal as an alternative to soybean meal in poultry diets. In this regard, it is crucial to understand all the possible aspects related to the chemical-nutritional characteristics, the effects on the animals’ health and welfare, and the safety of different insect meals. This study aimed to evaluate volatile fatty acids production in the caeca, the intestinal morphometry, and the brush border enzymatic activity of hens fed different levels of Hermetia illucens (Linnaeus) (Diptera: Stratiomyidae) larvae meal for 24 weeks. The research also aimed to contribute to the knowledge of the concentration of toxic elements in insect meals. Overall, the insect meal inclusion affected the small intestine morphometry, the enzymatic activity, and the caecal microbial activity. The soybean meal group showed the highest intestinal functionality, while a compensatory mechanism, probably mediated by the chitin, led to a positive increase of volatile fatty acids and butyrate in the 50% protein replacement diet with potential positive effects on gut healthiness. The levels of toxic elements in the diets and insect meal were lower than the maximum levels of heavy metals set by the EU Commission for the feed.To evaluate the effects of feeding a Hermetia illucens (HI) larvae meal on the different intestinal traits of hens, and to determine the toxic elements’ concentration in the insect meal and diets, 162 hens were randomly allotted to three groups. The control received a corn-soybean meal-based diet (SBM); the HI25 and HI50 groups received two diets in which the 25% and 50% of the dietary protein were replaced by the HI protein, respectively. The duodenal and jejunal villi height and villi/crypt were higher (p < 0.01) in the SBM than in the HI groups. The ileal villi height was higher (p < 0.05) in the SBM and HI25 groups than the HI50. The HI50 group exhibited a lower duodenal maltase activity. The intestinal alkaline phosphatase (IAP) activity linearly decreased in the duodenum and jejunum as the dietary insect meal inclusion increased. The HI50 group had a higher acetate and butyrate level than the SBM. The levels of cadmium (Cd), lead (Pb), mercury (Hg), and arsenic (As) in the diets and insect meal were lower than the maximum values established by the EU Commission. The 25% soybean protein replacement with Hermetia illucens larvae meal in the diet of laying hens was more suitable and closer to the optimal level than 50%.