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The role of insects for poultry feed: present and future perspective
Abstract
Insects have application in poultry feed because of their capacity to sustainably repurpose wastes into nutrient-dense feeds, combined with the demand for poultry meat and eggs in the diets of the growing human population. Additionally, poultry naturally consumes insects, thus insects may enhance poultry welfare. Several insects are commercially reared including the house cricket (Acheta domesticus L.), yellow mealworm (Tenebrio molitor L.), and black soldier fly larvae (Hermetia illucens L.). Insect nutrient concentrations are affected by species, stage of development, feedstock on which they are raised, and processing method. Insects are a concentrated source of energy and protein with an excellent balance of essential amino acids, of which methionine levels are higher than standard corn and soybean meal sources commonly utilized in poultry diets. Because they are readily eaten and well utilized by poultry, insects are an effective source of nutrition in poultry feed for a burgeoning world population.
Insect-derived ingredients, including whole larvae, protein-rich meal, and oil, have been extensively studied in recent years and shown to be a sustainable source of quality nutrition for virtually all animal species and life stages. In addition to the ability to use these ingredients as a source of essential nutrition, more recent research has demonstrated the potential for the immunomodulatory activity of various components of insect-derived ingredients. For all insects studied, antimicrobial peptides make up a critical part of the insects' innate immune system and these peptides have antimicrobial efficacy when purified from hemolymph and tested in vitro. From black soldier fly larvae, in particular, lauric acid is a predominant fatty acid deposited into the insect, and lauric acid also has potential antimicrobial activity in vitro and in vivo. Finally, the chitin and chitosan components of the insect exoskeleton may modulate microbial activity in a variety of ways. In companion animals, poultry, and livestock species, insect-derived ingredients have shown the potential to reduce the impact of actual or simulated disease challenge on several parameters of animal health and well-being. This review describes the current state of knowledge of the immunomodulatory potential of insect-derived ingredients.
Recently, the US FDA and Association of American Feed Control Officials approved Black Soldier Fly larvae (BSFL) as a feed ingredient for poultry. The objectives of this work were 1) to evaluate the nutritional profile of BSFL oil and meal in laying hens, and 2) measure the impact of the BSFL treatments on hen performance and egg quality. In two experiments BSFL oil and meal were fed to replicate hens from 43-47 wk and from 51 to 55 wk of age. The hens were fed iso-caloric, iso-nitrogenous diets with 3 treatment levels of BSFL oil (1.5, 3, and 4.5%, Exp. 1) or BSFL meal (8, 16 and 24%, Exp. 2). Data were analyzed by one-factor ANOVA for the main effect of diet and Tukey's multiple comparison for mean separation when significant. Exp. 1 results suggest BSFL oil could readily substituted for soybean oil with commercial hens at inclusion levels up to 4.5%. ADFI, BW, egg production, FCR, and egg weight were not impacted by the oil treatments (P>0.05). Yolk color among hens fed the BSFL oil was greater averaging 7.88 compared to 7.37 from Control hen eggs (P=0.0001). Exp. 2 diet formulation replaced soybean oil and meal with BSFL meal, and some additional corn was used in the higher BSFL diets. Diet amino acid balance at the highest level of inclusion (24% BSFL meal) indicates arginine and tryptophan are limiting and ADFI, BW and egg production were reduced (P<0.05). Egg production averaged 85.14% for the Control, 8 and 16% BSFL meal hens and was significantly greater than hens fed 24% meal at 77.01%. However, 8 and 16% BSFL meal levels had no negative impact on performance and were not significantly different than the Controls. Yolk color was again higher among the meal treatments compared to the control (P=0.0351). These experiments indicate that BSFL oil and meal can be used as dietary energy, protein and amino acids for hen maintenance, egg production and yolk coloration, although there may be upper limits of dietary inclusion.
Insect meal (IM) is a source of high-quality protein for aquafeed while insect oil (IO) is a source of fatty acids used in monogastric feed with identical or better performance than premium fishmeal (FM) or vegetable oils (VOs) respectively. Although insects’ ability to feed on agricultural by-products and the entire valorization of insect products (IM, IO, frass) suggest insect production is sustainable, no studies have documented its environmental impact using industrial-scale production data. The present study is the first attributional life cycle assessment (A-LCA) based on data from an industrial-scale facility implementing an innovative symbiosis production model. This A-LCA was used to (i) assess the environmental performance of the symbiosis model vs. a no-symbiosis model and (ii) compare the environmental impacts of IM and IO production vs. their respective alternatives. The results revealed that the symbiosis model introduces a meaningful change in terms of environmental footprint by reducing CO2 emissions by 80% and fossil resources depletion by 83% compared to the no-symbiosis model. The higher sustainability of the IM and IO produced using the symbiosis model was also demonstrated, as CO2 emissions were reduced by at least 55% and 83% when compared to the best FM and VOs alternatives, respectively.
The growing human population, changing dietary habits and intensifying competition between food and feed production underline the urgent need to explore novel sustainable production chains. In the past, the poultry sector has gained popularity due to its superior environmental and economic benefits comared to other livestock production systems. Therefore, it is of special interest to focus on refinement and innovation along the value chain to further improve the sector’s sustainability. One major issue is the transition towards sustainable protein sources in poultry feed. In this regard, insects are the secret rising stars. Insect species such as the black soldier fly (Hermetia illucens) and house fly (Musca domestica) have been proposed for farming as multifunctional mini-livestock for feed. One major property of these flies is that larvae can convert low-quality organic waste streams into valuable body mass containing high levels of high-quality protein and fat. Furthermore, the larvae are reported to have health- and welfare-promoting effects due to bioactive compounds and poultry having a natural interest in them. The aim of
the current paper is to discuss the state-of-the-art of using black soldier fly and house fly larvae as components of poultry feed and to highlight knowledge gaps, future opportunities and challenges. Some first studies have focussed on the successful partial replacement of soybean meal or fishmeal by these insects on poultry performance. However, since the sector is still in its infancy several uncertainties remain to be addressed. More research is required on identifying optimal inclusion levels, clearly differentiating between insect products based on their nutritional value and health-stimulating effects, and comparing the potential of insect products across species.
. Insects could be a potential replacement of protein-rich ingredients in poultry diets. Among these insects, black soldier fly (BSF), Hermetia illucens, has a high content of protein and fat, which reinforces the potential of using it in poultry feed formulation and makes it one of the most promising insect species for commercial production. Protein content as well as amino acid profile in H. illucens larvae is comparable to those in many protein-rich feedstuffs such as fish meal and soybean meal. BSF can convert organic wastes into a precious source of nutrients, such as proteins, lipids, and chitin, which contribute to reducing the environmental burden and pollution potential arising from organic waste accumulation. This review emphasizes the significance of this insect as a “green” technology in the extremely variable recycling of organic waste and generates a sustainable protein source as well as the importance of its use as a substitute of protein-rich feedstuff in poultry feed manufacturing.
Fast-growing broilers spend most their time inactive and are therefore prone to experience leg problems. Environmental enrichment that facilitates intrinsically motivated behaviours can potentially promote activity and reduce leg problems, thereby improving broiler welfare. A promising environmental enrichment method is the scattering of desired feed items, such as insects, which are highly attractive to broilers. We studied the effect of providing live black soldier fly larvae (BSFL) scattered on the litter on broiler behaviour, leg health and performance. One-day-old male broilers were assigned to one of five treatments (eight pens/treatment, nine broilers/pen): a control without BSFL and four treatments with BSFL provided from day 1 onwards in different amounts (5% or 10% of estimated dietary dry matter intake; A5 and A10 respectively) and frequencies (two or four times a day; F2 and F4 respectively). All broilers were fed diets formulated to ensure a similar energy and nutrient intake. Broiler weight and leg health were determined on day 42. The behavioural time budget was determined weekly by observations for 7 h per day using 12-min scan sampling, and activity around larval provisioning was determined by 3-min scan sampling from 9 min before, until 30 min after larval provisioning on day 15/16, 29/30 and 40/41. Broilers in all larval provisioning treatments had a different behavioural time budget than controls, with significantly higher levels of foraging behaviour, walking, standing idle and general activity during at least three of the five observation days (p < 0.05 compared to controls). The increase in activity was numerically highest and most long-term in A10F4 broilers. Time spent active and in standing posture declined from week 4 onwards in A10F4, whereas for all other treatments this decline occurred already in week 2. Activity during 30 minutes after larval provisioning was higher for A10 than A5 treatments (p < 0.05 for all days) but overall not affected by frequency of larval provisioning. Hock burn occurred less in A10 birds than in controls (p < 0.05), and lameness occurred less in A10 and A5F4 birds than in controls (p < 0.01). Only A10F2 birds had a lower final weight than controls (p < 0.05). In conclusion, the largest amount combined with the highest frequency of larval provisioning applied in this study resulted in the most prominent increase in activity and better leg health, without significantly affecting broiler performance. Further investigation into BSFL provisioning methods is required to determine the optimal method for achieving improved broiler welfare.
Effects of total replacement of soybean meal (SBM) with defatted black soldier fly larvae meal (BSFLM) on egg production and quality, organ weight, and apparent retention (AR) of components were investigated in Shaver White hens from 28 to 43 wk of age. A total of 108 birds, (6 birds/cage) were assigned to three diets (6 replicates/diet). Diets were control corn-SBM diet and two additional diets made with the addition of either 10 or 15% BSFLM. Diets met or exceeded breeder specifications, contained TiO2 as an indigestible marker, and were prepared in pellet form. Birds had free access to feed and water throughout the experiment. Hen-day egg production (HDEP) was monitored daily. Feed intake (FI) and body weight (BW) were monitored in 4-wk intervals. All eggs laid on the sixth day of wks 31, 35, 39, and 43 were used for egg weight (EW), Haugh units (HU), yolk color (YC), shell breaking strength (SBS), and shell thickness (ST). Excreta samples were collected for 3 consecutive days on wk 33 for AR and two birds/cage were necropsied at the end. There were no (P > 0.05) diet effects on HDEP, FI, and HU. Inclusion of BSFLM linearly decreased (P < 0.05) egg mass and feed conversion ratio (FCR) and quadratically increased (P < 0.05) BW. There was no (P > 0.05) interaction between diet and sampling time point on egg quality parameters. Inclusion of BSFLM increased SBF and YC linearly (P < 0.05) and ST quadratically (P = 0.028). Inclusion of BSFLM quadratically (P ≤ 0.01) reduced empty ceca weight and increased liver weight and had no effect (P > 0.05) on gizzard, small intestine, and pancreas weights. Feeding BSFLM linearly (P = 0.001) and quadratically (P = 0.007) increased apparent metabolizable energy (AME). Data showed that defatted BSFLM resulted in deeper orange yolks and improved eggshell quality; however, unfavorable FCR linked to lighter eggs as well as heavier birds and liver warrants further investigations.
Yellow mealworm meal (MWM) as a protein feedstuff in the broiler diet was investigated based on the growth performance, hematological characteristics, carcass, and meat quality of broiler chicks. A total of 700 one-day-old Ross 308 male broiler chicks were assigned to five dietary MWM treatments containing 0%, 2%, 4%, and 8% dried MWM or 10.48% fresh mealworm (corresponding to 4% dried MWM). For each treatment, there were seven pens with 20 chicks each. The nutritional profile of dried MWM is comparable to all conventional protein feedstuffs. MWM significantly increased BW and ADG (linear and quadratic, p < 0.05), and FCR was best at 4% MWM inclusion level (quadratic, p < 0.10) for broiler chicks during the starter phase. The predicted MWM levels for optimal starter BW and ADG were 4.13% and 3.84%. Hematological characteristics of broiler chicks fed on the MWM diet did not differ or showed small change within the physiological range. A fresh 10.48% mealworm diet significantly reduced the blood LZM for the grower. Broiler Chicks fed on fresh 10.48% mealworm had a significantly reduced abdominal fat percentage compared to the 4% dried MWM counterparts. MWM did not significantly affect meat quality. Taken together, MWM inclusion in broiler diet is acceptable as a protein feedstuff, and a 4% level could stimulate early growth in the starter phase.
Feather pecking is a key welfare challenge in laying hen husbandry. Feeding of live Hermetia illucens larvae could provide a possible solution to reduce feather pecking in hens. This research investigates effects of dispensing live H. illucens larvae to non-beak trimmed older laying hens on production performance, behavior and welfare. Control treatment hens were provided a commercial diet, while larvae treatment hens were provided live H. illucens larvae (using special dispenser) on top of a soy-free diet. Feather condition, production performance and egg quality were measured during the initiation (67 weeks age) and termination (78 weeks age) of the trial. Behavior of birds was monitored using video recording. Feed conversion ratio, body weight gain and egg laying parameters were similar for both treatments. At termination of the trial, larvae-fed hens exhibited better feather condition in comparison to control hens (p = 0.004). Behavioral observations indicated that larvae provision influenced the number of birds on floor during morning and afternoon hours. In conclusion, live H. illucens larvae could successfully replace soy in diets of older laying hens (in combination with local plant proteins). Provisioning of these insects also had a positive effect on the feather condition of laying hens with intact beaks.
Helicobacter pylori (Marshall & Goodwin) is a widespread human pathogen that is acquiring resistance to the antibiotics used to treat it. This increasing resistance necessitates a continued search for new antibiotics. An antibiotic source that shows promise is animals whose immune systems must adapt to living in bacteria-laden conditions by producing antibacterial peptides or small molecules. Among these animals is the black soldier fly (BSF; Hermetia illucens Linnaeus), a Diptera that colonizes decomposing organic matter. In order to find anti-H. pylori peptides in BSF, larvae were challenged with Escherichia coli (Enterobacteriales: Enterobacteriaceae). Small peptides were extracted from hemolymph and purified using solid-phase extraction, molecular weight cutoff filtration and two rounds of preparative high performance liquid chromatography (HPLC). The anti-H. pylori fraction was followed through the purification process using the inhibition zone assay in brain-heart infusion agar, while peptides from uninoculated larvae had no activity. The inhibition halo of the active sample was comparable to the action of metronidazole in the inhibition zone assay. The purified sample contained four peptides with average masses of approximately 4.2 kDa that eluted together when analyzed by HPLC-mass spectrometry. The peptides likely have similar sequences, activity, and properties. Therefore, BSF produces inducible antibacterial peptides that have in vitro activity against H. pylori, which highlights BSF's position as an important target for further bioprospecting.
This study was conducted to investigate the effect of insect full-fat meals (Tenebrio molitor and Zophobas morio larvae), added “on top” of a complete diet or calculated into diets, on the growth performance, selected blood, and immune system traits of broiler chickens. 1,000 one-day-old female Ross 308 broiler chicks were used in 2 independent experiments. In the first trial, the birds were randomly assigned to 6 treatments, 10 replicate pens per treatment, and 10 birds per pen, i.e., negative control; positive control with salinomycin addition (60 mg/kg diet), and addition of 0.2% and 0.3% of T. molitor and Z. morio full-fat meals “on top". In the second experiment, 4 treatments, 10 replicate pens per treatment, and 10 birds per pen were set, i.e., negative control, positive control with salinomycin addition (60 mg/kg diet), and 0.3% of T. molitor and Z. morio full-fat meals calculated in the diets. In both trials the supplementation of insects increased the BWG (Exp. 1: P = 0.024; Exp. 2: P = 0.046) and FI (Exp. 1: P = 0.022; Exp. 2: P = 0.026), and no negative effect on the FCR was recorded in experiment one (P = 0.514), however in second trial insects addition increased FCR values (P = 0.011). In addition, in the first trial, groups fed insects and PC comparing to NC decreased the IgY (P = 0.045) and IgM, (P < 0.001) levels. In the second experiment, IgM levels were also decreased (P < 0.001) in groups fed insects comparing to NC. Moreover, in first trial the IgM levels were negatively correlated to the BWG (r = –0.4845) and FI (r = –0.4986), with statistically significant values (P < 0.001). In conclusion, the current results confirmed that small amount addition (0.2% and 0.3%) of T. molitor and Z. morio full-fat meals to the diet of broiler chickens can improve growth performance and change selected the immune system traits.
The aim of this study was to evaluate the in vitro antibacterial activity of Black soldier fly (BSF) larva extract. The BSF larva was extracted using methanol and then tested for antibacterial activity using agar diffusion method (zone growth inhibition). The antibacterial activity was conducted against Salmonella sp. and Escherichia coli, two important bacterial strains in poultry, using six dilution levels (10 mg/ml, 20 mg/ml, 40 mg/ml, 80 mg/ml, 160 mg/ml and 320 mg/ml). All the results were subjected analyze using t-test method. Based on the diameter of the inhibition zone, the BSF larva extract has a strong (P<0.05) antibacterial activity against Salmonella sp. and E. coli when the concentration used 320 mg/ml. In addition, BSF larva extract also contain high amount of lauric acid (49.18%), a saturated fatty acid that has been proven to proposes as antibacterial agent. Therefore, it could be concluded that the BSF larva extract could be used as a candidate for antibacterial substances.
This research aimed at improving the fatty acid (FA) profile of Hermetia illucens larvae (HI) and evaluating the effects of their inclusion in growing broiler quails’ diets on the meat physicochemical quality, including detailed amino acid (AA) and FA profiles, sensory traits, and retail display. HI larvae were reared on two different substrates: layer mash (HI1) and 50:50 layer mash/fish offal (HI2). A total of 300 10-day-old quails were allocated to the three dietary groups (five replicates/each): a soybean meal-based diet was formulated (Control), and two other diets were formulated that included either 10% HI1 or HI2. Quails were fed the experimental diets until slaughter. Diets were formulated to be isonitrogenous and isoenergetic. Breast meat quality was affected by the dietary treatments, which displayed different proximate compositions and AA and FA profiles. Meat physical quality, sensory profile, and retail display remained unaffected for the most part. Overall, results showed that it is possible to improve the FA profile of the HI-fed quails’ meat and thus lipid quality through substrate modulation of the HI’s diet.
Background:
The present work is aimed at evaluating the effect of different inclusion levels of a partially defatted black soldier fly (Hermetia illucens, L.; HI) larva meal for ducks. A total of 192 female 3-day-old Muscovy ducklings (Cairina moschata domestica, Canedins R71 L White, Grimaud Freres Selection, France) were divided into 4 groups, assigned 4 different dietary treatments (6 replicates/treatment and 8 birds/replicate) and reared from 3 to 50 days of age. HI larva meal was included at increasing levels (0, 3%, 6% and 9%, HI0, HI3, HI6 and HI9, respectively) in isonitrogenous and isoenergetic diets formulated for 3 feeding phases: starter (3-17 days of age), grower (18-38 days of age) and finisher (39-50 days of age). The growth performance and apparent total tract digestibility were evaluated during the trial using titanium dioxide as an inert marker (0.3% of inclusion). At 51 days of age, two birds per pen were slaughtered and histomorphological investigations were performed.
Results:
The live weight and average daily gain showed a quadratic response to increasing HI meal in the grower period (minimum corresponding to the HI6 group). No effects of dietary inclusion levels were observed for the daily feed intake or feed conversion ratio. The apparent dry matter and organic matter digestibility were not affected by the dietary treatment. A linear decrease was observed for the crude protein apparent digestibility in the starter period (minimum for the HI9 groups). The ether extract apparent digestibility increased linearly during the grower and finisher periods (minimum for the HI0 group). The morphometric indices were not influenced by the dietary treatments.
Conclusions:
The inclusion of up to 9% of HI partially defatted larva meal in the diet of ducks did not cause any effect on growth performance, as well as the apparent digestibility. Moreover, dietary HI inclusion preserved the physiological intestinal development.
In 2018, the industrial compound feed production throughout the world was 1103 metric billion tons, which was an increase of 3% compared to 2017. In order to meet the needs of the increasing population, a further increment in compound feed production is necessary. Conventional protein sources are no longer suitable to completely satisfy the increment of feed production in a sustainable way. Insects are one of the most promising options, due to their valuable nutritional features. This paper reviews the state-of-the-art of research on the use of insect meals and oils in aquatic, avian and other animal species diets, focusing mainly on the effects on digestibility, performance and product quality. In general, insect-derived product digestibility is affected by the insect species, the inclusion levels and by the process. Sometimes, the presence of chitin can lead to a decrease in nutrient digestibility. The same considerations are true for animal performance. As far as product quality is concerned, a dramatic effect of insect products has been recorded for the fatty acid profile, with a decrease in valuable n3 fatty acids. Sensory analyses have reported no or slight differences. Insect-derived products seem to be a good alternative to conventional feed sources and can make an important contribution to the sustainable development of the livestock industry.
Recently, insects have received increased attention as an important source of sustainable raw materials for animal feed, especially in fish, poultry, and swine. In particular, the most promising species are represented by the black soldier fly (Hermetia illucens, HI), the yellow mealworm (Tenebrio molitor, TM), and the common house fly (Musca domestica, MD). Although rapid development is expected, insects remain underutilized in the animal feed industry mainly due to technical, financial, and regulatory barriers. In addition, few works have analyzed consumer and stakeholder points of view towards the use of insects as animal feed. In this article, we summarize the main findings of this body of research and provide a discussion of consumer studies regarding the consumption of animals fed with insects. Our review suggests that consumer acceptance will not be a barrier towards the development of this novel protein industry. Furthermore, we conclude that it will be of interest to understand whether the use of this more sustainable feed source might increase consumer willingness to pay for animal products fed with insects and whether the overall acceptability, from a sensory point of view, will be perceived better than conventional products. Finally, the main challenges of the feed farming industry are addressed.
Yellow mealworm (Tenebrio molitor L.) represents a sustainable source of proteins and fatty acids for feed and food. Industrial production of mealworms necessitates optimized processing techniques, where drying as the first postharvest procedure is of utmost importance for the quality of the final product. This study examines the nutritional quality of mealworm larvae processed by rack oven drying, vacuum drying or freeze drying, respectively. Proximate composition and fatty acid profile were comparable between the dried larvae. In contrast, larvae color impressions and volatile compound profiles were very much dependent on processing procedure. High-temperature rack oven drying caused pronounced darkening with rather low content of volatiles, pointing toward the progress of Maillard reaction. On the other hand, vacuum drying or freeze drying led to enrichment of volatile Maillard reaction and lipid oxidation intermediates, whose actual sensory relevance needs to be clarified in the future. Beyond sensory and visual importance drying intermediates have to be considered with regard to their metal ion chelating ability; in particular for essential trace elements such as Zn 2+. This study found comparable total zinc contents for the differently dried mealworm samples. However, dried larvae, in particular after rack oven drying, had only low zinc accessibility, which was between 20% and 40%. Therefore, bioaccessibility rather than total zinc has to be considered when their contribution to meeting the nutritional requirements for zinc in humans and animals is evaluated.
Novel foods represent sustainable alternatives to traditional farming and conventional foodstuffs. The house cricket (Acheta domesticus) is considered as one of the most promising reared insects due to their attractive nutritional profile and lower feed conversion ratio compared to other animals. However, putative health hazards associated with consumption of crickets have previously not been investigated. The present study assesses the risks of A. domesticus reared in closed systems controlled by the implementation of hazard analysis and critical control points and good farming practices. Due to the novelty of the topic, data scarcity has been a limiting factor, hence comparative evidence from closely related species belonging to the order Orthoptera (e.g. grasshoppers, locusts, and other cricket species) have been included. The present risk profile identified as main hazards: (1) high total counts of aerobic bacteria; (2) presence of spore-forming bacteria post thermal processing; (3) accumulation of cadmium and other heavy metals; and (4) a possible increase of allergenic reactions due to exposure to insects and insect derived products. Important data gaps regarding edible crickets and their safety as novel foods have been highlighted in the future perspective section, representing aims for future research. Identified data gaps include: (1) farming conditions of the insects being studied; (2) data on the impact of thermal processing of the products prior to consumption; (3) fungal communities and mycotoxins-producing fungi in reared crickets; and (4) heavy metals not fully assessed (chromium, aluminium and arsenic) and other chemical hazards produced during processing (i.e. heterocyclic aromatic amines, acrylamide). The present risk profile explores food safety risks related to consumption of A. domesticus, thereby constituting an example of chemical and microbial hazards risk profiling on edible insects, covering rearing to consumption.
Black soldier fly (BSF, Hermetia illucens L.), an insect with high protein, has been proposed as a sustainable protein resource alternative for both food and feed for their nutritional composition and ease of rearing. The amino acid composition, nutritional value, in vitro digestibility, morphologies, and thermal properties of the BSF larvae proteins (BSFLP) based on two drying methods were investigated. Experimental results showed that their amino acid score could reach the requirement of FAO/WHO (dietary protein quality evaluation in human nutrition. Report of an FAO expert consultation. Food and nutrition paper no. 92. Food and Agriculture Organization and the World Health Organization, Rome, 2013) for indispensable amino acids for older children, adolescents, and adults. The proportion of essential amino acids to total amino acids (E/T) of both conventional dried BSFLP (CD-BSFLP) and microwave dried BSFLP (MD-BSFLP) was more than 40%. Lysine and valine were found to be the first limiting amino acid for CD-BSFLP and MD-BSFLP, respectively. Both of the in vitro digestible indispensable amino acid score (DIAAS) values of the BSFLP were more than 75%. The results of scanning electron microscopy, thermo-gravimetric analysis, and differential scanning calorimetry of the samples showed that microwave drying polymerized the protein particles and made them harder to digest. In conclusion, the BSFLP prepared by conventional drying (60 °C) had higher DIAAS and better digestibility. Moreover, the amino acid composition and high DIAAS (> 75%) indicated that the BSFLP could be utilized as a good source of animal protein for human nutrition.
The future of meat
Meat consumption is rising annually as human populations grow and affluence increases. Godfray et al. review this trend, which has major negative consequences for land and water use and environmental change. Although meat is a concentrated source of nutrients for low-income families, it also enhances the risks of chronic ill health, such as from colorectal cancer and cardiovascular disease. Changing meat consumption habits is a challenge that requires identifying the complex social factors associated with meat eating and developing policies for effective interventions.
Science , this issue p. eaam5324
Vertebrates obtain the prohormone vitamin D primarily by endogenous cutaneous synthesis under ultraviolet b (UVb) exposure. To date, endogenous synthesis of vitamin D in insects has never been investigated. In an initial experiment, we exposed four insect species which differ in ecology and morphology (migratory locusts, house crickets, yellow mealworms and black soldier fly larvae (BSFL)) to a low irradiance UVb source. In a second experiment we exposed these species to a higher UV irradiance, and in a third we tested the effect of exposure duration on vitamin D concentrations in yellow mealworms. Low irradiance UVb tended to increase vitamin D3 levels in house crickets, vitamin D2 levels in BSFL and vitamin D2 and D3 in yellow mealworms. Higher UVb irradiance increased vitamin D3 levels in all species but BSFL. Both BSFL and migratory locusts had increased vitamin D2 levels. Longer UVb exposure of yellow mealworms increased vitamin D2 and increased vitamin D3 until a plateau was reached at 6400 IU/kg. This study shows that insects can synthesize vitamin D de novo and that the amounts depend on UVb irradiance and exposure duration.
Background
The present study has evaluated the effects of different inclusion levels of a partially defatted black soldier fly (Hermetia illucens L.; HI) larva meal on the growth performance, blood parameters and gut morphology of broiler chickens. A total of 256 male broiler chickens (Ross 308) were reared from d 1 to d 35 and assigned to 4 dietary treatments (8 replicates/treatment and 8 birds/replicate). HI larva meal was included at increasing levels (0, 5%, 10% and 15%; HI0, HI5, HI10 and HI15, respectively) in isonitrogenous and isoenergetic diets formulated for 3 feeding phases: starter (1–10 d), growing (10–24 d) and finisher (24–35 d). Two birds per pen were slaughtered at d 35 and morphometric investigations and histopathological alterations were performed.
Results
The live weight (LW) showed linear and quadratic responses to increasing HI larva meal (maximum for HI10 group). Average daily gain (ADG) showed a linear and quadratic responses to HI meal (maximum for HI10 group) during starter and growing periods. A linear decrease was observed for ADG during the finisher period. The daily feed intake (DFI) showed a linear and quadratic effect during the starter period (maximum for HI10 group). Linear and quadratic responses were observed for the feed conversion ratio (FCR) in the growing period and for the whole period of the experiment. The FCR showed a linear response in the finisher period (maximum for HI15). No significant effects were observed for the blood and serum parameters, except for the phosphorus concentration, which showed linear and quadratic responses as well as glutathione peroxidase (GPx) activity, the latter of which showed a linear response. The HI15 birds showed a lower villus height, a higher crypt depth and a lower villus height-to-crypt depth ratio than the other groups.
Conclusions
Increasing levels of dietary HI meal inclusion in male broiler chickens may improve the LW and DFI during the starter period, but may also negatively affect the FCR and gut morphology, thus suggesting that low levels may be more suitable. However, no significant effects on the haematochemical parameters or histological findings were observed in relation to HI meal utilization.
Taking the macromarketing approach to insect food and feed, we study how the global insect marketing system is impacted by the global insect regulatory system. As an illustration, we study how the regulations of the European Union, USA, Canada and Australia impact marketing strategies of individual companies, and how company-level behaviour combines into the dynamics of the whole insect marketing system. The output of the global insect marketing system is the global assortment of insect products. The regulatory system has its topics, content, and tools with differences between countries. Topics are the elements of the insect business that regulators care about. Content determines what insect products can be launched. Tools are the regulatory instruments and sanctions. Regulatory differences between countries are an important determinant in the geography of launch patterns and in the resulting global assortment of insect products available.
We examined egg production and quality responses of adding up to 7.5% defatted black soldier fly larvae meal (BSFLM) in a corn–soybean meal diet fed to pullets (19 to 27 wk of age). The concentration of CP and crude fat in BSFLM sample was 59.3 and 7.0% DM, respectively. A corn–soybean meal diet was formulated with 0 or 5.0 or 7.5% BSFLM and fed (n = 6) to a total of 108, 19-wk-old Shaver White pullets placed in conventional cages (6 birds/cage). The birds had free access to feed and water. Hen-day egg production (HDEP) and average egg weight were monitored daily and feed intake (FI) weekly. Egg quality parameters were assessed on individual eggs collected on the 5th d of wk 22, 24, and 26 and included individual EW (IEW), albumen height (HU), yolk color (YC), egg shell-breaking strength (SBS) and thickness (ST). A quadratic response (P < 0.02) was observed for HDEP, EW and egg mass. Specifically, birds fed 0 and 7.5% BSFLM diets had similar (P > 0.05) values for these parameters with birds fed 5.0% BSFLM showing lower (P < 0.05) HDEP than 0 or 7.5% BSFLM fed birds. The HDEP was 89.4, 84.8, and 87.8 for 0, 5.0, and 7.5% BSFLM, respectively. Feeding BSFLM linearly (P < 0.01) increased FI and feed conversion ratio (FCR) (FI/egg mass). There was no diet effect (P > 0.05) on IEW and HU, however, BSFLM linearly (P = 0.02) reduced CV of IEW. The IEW was 53.7, 52.3, and 53.0 g for 0, 5.0, and 7.5% BSFLM-fed birds, respectively and corresponding CV values of IEW were 7.9, 5.2, and 5.1%. Feeding BSFLM linearly (P < 0.01) increased YC, SBS, and ST. In conclusion, birds fed 7.5% BSFLM had similar HDEP and egg mass but poor FCR relative to corn–soybean meal diet without BSFLM. The effects of BSFLM on egg quality characteristics warrant further investigations.
The effects on meat quality resulting from alternative dietary protein sources (Spirulina and Hermetia meal) in poultry diets are studied to determine the overall suitability of these ingredients considering state-of-the-art packaging practices—highly oxygenated modified atmosphere packaging (HiOx MAP). We monitored standard slaughterhouse parameters, such as live weight, carcass weight, dressed yield, and pH at 20 min and 24 h post mortem. In addition, we studied the effects that 3 and 7-day storage in HiOx MAP has on the overall product physico-chemical and sensory properties. In addition to previously supported effects of HiOx MAP, we found that meat quality could be improved when Spirulina replaces 50% of the soy protein in broiler diets; however, this substitution results in a dark reddish-yellowish meat colour. On the other hand, the substitution with Hermetia larval meal results in a product that does not differ from the standard fed control group, with the exception that the breast filet has a more intense flavour that decreases over storage time. All-in-all Spirulina and Hermetia meal have the potential to replace soybean meal in broiler diets without deteriorating meat quality.
Food futurists accept that sustainability-minded humanity will increasingly incorporate insects as alternative protein. The most studied and easily reared species are not necessarily the most sustainable, acceptable, or delicious. Here, we review the literature on the black soldier fly, Hermetia illucens, which is capable of efficiently converting a wide variety of organic materials, from food waste to manure, into insect biomass. They can be grown and harvested without dedicated facilities and are not pestiferous. Their larvae are 42% crude protein and 29% fat, although they are higher in saturated fats than most insects. They do not concentrate pesticides or mycotoxins. They are already grown and recommended for use as animal feed, but with regional legal restrictions on how this is done. For commercial use in human foods, larvae could potentially be milled and converted into a textured protein with a strong flavor. Their biggest advantage over other insects is their ability to convert waste into food, generating value and closing nutrient loops as they reduce pollution and costs. This general advantage is also their greatest disadvantage, for the social stigmas and legal prohibitions against eating organisms that eat waste are added to extant taboos facing insect consumption.
Methicillin-resistant Staphylococcus aureus (MRSA), are the most frequent cause of sepsis, which urgently demanding new drugs for treating infection. Two homologous insect CSαβ peptides-DLP2 and DLP4 from Hermetia illucens were firstly expressed in Pichia pastoris, with the yields of 873.5 and 801.3 mg/l, respectively. DLP2 and DLP4 displayed potent antimicrobial activity against Gram-positive bacteria especially MRSA and had greater potency, faster killing, and a longer postantibiotic effect than vancomycin. A 30-d serial passage of MRSA in the presence of DLP2/DLP4 failed to produce resistant mutants. Macromolecular synthesis showed that DLP2/DLP4 inhibited multi-macromolecular synthesis especially for RNA. Flow cytometry and electron microscopy results showed that the cell cycle was arrested at R-phase; the cytoplasmic membrane and cell wall were broken by DLP2/DLP4; mesosome-like structures were observed in MRSA. At the doses of 3 7.5 mg/kg DLP2 or DLP4, the survival of mice challenged with MRSA were 80 100%. DLP2 and DLP4 reduced the bacterial translocation burden over 95% in spleen and kidneys; reduced serum pro-inflammatory cytokines levels; promoted anti-inflammatory cytokines levels; and ameliorated lung and spleen injury. These data suggest that DLP2 and DLP4 may be excellent candidates for novel antimicrobial peptides against staphylococcal infections.
Black soldier fly (Hermetia illucens) larvae are a promising source of protein and lipid for animal feeds. The nutritional composition of the BSF larvae depend partly on the composition of the feeding medium. The BSF lipid profile in part mimics the feeding media lipid profile, and micronutrients, like minerals and vitamins, can readily accumulate in black soldier fly lar-vae. However, investigative studies on bioconversion and accumulation of nutrients from media to black soldier fly larvae are scarce. Here we show that inclusion of the brown algae Ascophyllum nodosum in the substrate for black soldier fly larvae can introduce valuable nutrients, commonly associated with the marine environment, into the larvae. The omega-3 fatty acid eicosapentaenoic acid (20:5n-3), iodine and vitamin E concentrations increased in the larvae when more seaweed was included in the diet. When the feeding media consisted of more than 50% seaweed, the larvae experienced poorer growth, lower nutrient retention and lower lipid levels, compared to a pure plant based feeding medium. Our results confirm the plasticity of the nutritional make-up of black soldier fly larvae, allowing it to accumulate both lipid-and water-soluble compounds. A broader understanding of the effect of the composition of the feeding media on the larvae composition can help to tailor black soldier fly lar-vae into a nutrient profile more suited for specific feed or food purposes.
Black soldier fly (BSF) larvae, Hermetia illucens L., develops on organic wastes, reducing ecological pollution and converting waste biomass into protein and fat rich insect biomass. BSF can replace increasingly expensive protein sources used in poultry, aquaculture and livestock compound diet formulation, such as fish meal and soybean meal, which holds the potential to alleviate future food and feed insecurity. The fate of nutritional spectra in BSF during its life cycle phases is still poorly understood. This study assessed metabolic changes in nutrition composition of BSF from egg to adult. A rapid increase of crude fat content was observed since the development of 4–14 days of larvae with its maximum level reaching 28.4% in dry mass, whereas the crude protein displayed a continuous decreasing trend in the same development phases with minimum level of 38% at larval phase (12 days) and peak level of 46.2% at early pupa stage. A sharp drop in crude fat was noticed from early prepupae to late pupae (24.2%, 8.2% respectively). However crude protein shows its maximum value being 57.6% at postmortem adult stage with 21.6% fat level. In addition, fatty acids, amino acids, minerals and vitamins composition in different development stages of BSF were presented and compared. Findings from this study could provide podium to food and feed industry for framing a strategy for specific molecular nutritional component intake into the diets of humans, aquaculture and animals. It is also indicated that BSF is a possible insect which can be applied to combating the food scarcity of countries where micronutrient deficiency is prevalent. Moreover it contributes to advance exploring for developmental and metabolic biology of this edible insect.
Chitin, a polymer of N-acetyl-D-glucosamine (GlcNAc), functions as a major structural component in crustaceans, insects and fungi and is the second most abundant polysaccharide in the nature. Although these chitin-containing organisms have been suggested as novel animal feed resources, chitin has long been considered as indigestible fibers in the animal body. Recently, we reported that acidic chitinase (Chia) is a protease-resistant major glycosidase in mouse gastrointestinal tract (GIT) and that it digests chitin in the mouse stomach. However, the physiological role of Chia in other animals including poultry remains unknown. Here, we report that Chia can function as a digestive enzyme that breaks down chitin-containing organisms in chicken GIT. Chia mRNA is predominantly expressed in the glandular stomach tissue in normal chicken. We also show that chicken Chia has a robust chitinolytic activity at pH 2.0 and is highly resistant to proteolysis by pepsin and trypsin/chymotrypsin under conditions mimicking GIT. Chia degraded shells of mealworm larvae in the presence of digestive proteases and produced (GlcNAc)2. Thus, functional similarity of chicken Chia with the mouse enzyme suggests that chitin-containing organisms can be used for alternative poultry diets not only as whole edible resources but also as enhancers of their nutritional value.
Background
The study aimed to determine the apparent total tract digestibility coefficients (ATTDC) of nutrients, the apparent metabolizable energy (AME and AMEn) and the amino acid (AA) apparent ileal digestibility coefficients (AIDC) of a partially defatted (BSFp) and a highly defatted (BSFh) black soldier fly larvae meal. The experimental diets were: a basal diet and two diets prepared by substituting 250 g/kg (w/w) of the basal diet with BSFp or BSFh, respectively.
Results
Significant differences were found between BSFp and BSFh meals for ATTDC of the nutrients: BSFp resulted more digestible than BSFh, except for ATTDC of CP which did not differed between meals, while a statistical trend was observed for ATTDC of DM and EE. The AME and AMEn values were significantly (P < 0.05) different between the two BSF meals, with higher levels for BSFp (16.25 and 14.87 MJ/kg DM, respectively). The AIDC of the AA in BSFp ranged from 0.44 to 0.92, while in BSFh they ranged from 0.45 to 0.99. No significant differences were observed for the AA digestibility (0.77 and 0.80 for BSFp and BSFh, respectively), except for glutamic acid, proline and serine that were more digestible in the BSFh meal (P < 0.05).
Conclusions
Defatted BSF meals can be considered as an excellent source of AME and digestible AA for broilers with a better efficient nutrient digestion. These considerations suggested the effective utilization of defatted BSF larvae meal in poultry feed formulation.
The Toll signaling pathway is responsible for defense against both Gram-positive bacteria and fungi. Gram-negative binding protein 3 (GNBP3) has a strong affinity for the fungal cell wall component, β-1,3-glucan, which can activate the prophenoloxidase (proPO) cascade and induce the Toll signaling pathway. Myeloid differentiation factor 88 (MyD88) is an intracellular adaptor protein involved in the Toll signaling pathway. In this study, we monitored the response of 5 key genes (TmGNBP3, TmMyD88, and Tenecin 1, 2, and 3) in the Toll pathway of the mealworm Tenebrio molitor immune system against the fungus Beauveria bassiana JEF-007 using RT-PCR. TmGNBP3, Tenecin 1, and Tenecin 2 were significantly up-regulated after fungal infection. To better understand the roles of the Toll signaling pathway in the mealworm immune system, TmGNBP3 and TmMyD88 were knocked down by RNAi silencing. Target gene expression levels decreased at 2 days post knockdown and were dramatically reduced at 6 days post-dsRNA injection. Therefore, mealworms were compromised by B. bassiana JEF-007 at 6 days post-dsRNA injection. Silencing of TmMyD88 and TmGNBP3 resulted in reduced resistance of the host to fungal infection. Particularly, reducing TmGNBP3 levels obviously down-regulated Tenecin 1 and Tenecin 2 expression levels, whereas silencing TmMyD88 expression resulted in decreased Tenecin 2 expression. These results indicate that TmGNBP3 is essential to induce downstream antifungal peptide Tenecin 1 expression against B. bassiana JEF-007. This article is protected by copyright. All rights reserved.
The aim of the research was to study the effects of an insect meal from Hermetia illucens larvae (HILM) as complete replacement of soybean meal (SBM) on productive performance and blood profiles of laying hens, from 24 to 45 wk of age. A total of 108 24-week-old Lohmann Brown Classic laying hens was equally divided into 2 groups (54 hens/group, 9 replicates of 6 hens/group). From 24 to 45 wk of age, the groups were fed 2 different isoproteic and isoenergetic diets: the control group (SBM) was fed a corn-soybean meal based diet, while in the HILM group the soybean meal was completely replaced by Hermetia illucens larvae meal. Feed intake, number of eggs produced, and egg weight were recorded weekly along the trial. At 45 wk of age, blood samples were collected from 2 hens per replicate. The use of HIML led to a more favorable (P < 0.01) feed conversion ratio in hens but lay percentage, feed intake, average egg weight, and egg mass were higher (P < 0.01) in hens fed the SBM diet. Hens fed insect meal produced a higher percentage of eggs from small (S), medium (M), and extra-large (XL) classes (P < 0.01) than SBM, while the SBM group had a higher percentage of eggs from the large (L) class (P < 0.01). The levels of globulin and albumin to globulin ratio were, respectively, higher and lower (P < 0.05) in HILM than the SBM group. Cholesterol and triglycerides were higher (P < 0.05 and P < 0.01, respectively) in hens from SBM than in the HILM group. Blood levels of Ca were higher (P < 0.01) in hens fed insect meal, while creatinine was higher (P < 0.01) in blood of hens fed SBM. Hermetia illucens larvae meal can be a suitable alternative protein source for laying hens even if the complete replacement of soybean meal needs further investigation to avoid the negative effects on feed intake.
The present research studied for the first time the potential application of the fat derived from the black soldier fly larvae fat (BSLF) in substitution to the soybean oil in the diet for broiler chickens: growth performances, feed-choice, blood traits, carcass characteristics and meat quality were considered in this study. A total of 150 male broiler chicks (Ross 308) at one-day of age were randomly allotted to 3 dietary treatments (5 replicates and 10 birds/pen): a basal control diet (C group), and the same diet in which the soybean oil was replaced by 50% (CH group) or 100% (H group) BSLF. Growth performances, feed-choice test, blood traits and slaughtering performances were not influenced by diets. Independently of BSLF inclusion, broiler chickens breast meat had also similar crude protein and ether extract contents and displayed similar thawing loss. Furthermore, pH, L*, a*, b* colour values, and drip loss were unaffected by dietary treatments both at 0 and 9 days of refrigerated storage. As expected, the fatty acid profile of broiler chickens breast was greatly affected by BSLF inclusion level. With increasing BSLF inclusion rate, the proportion of SFA increased (32.2, 37.8, 43.5% for C, CH and H breast meat, respectively, p < .001) to the detriment of the PUFA fraction (22.7, 23.0, 22.9% for C, CH and H breast meat, respectively, p < .001). On the contrary, MUFA fraction was unaffected. BSLF inclusion guaranteed satisfactory productive performances, carcass traits and overall meat quality, thus suggesting that BSLF could be a promising new feed ingredient for chickens.
Insects have potential as a novel source of protein in feed and food production in Europe, provided they can be used safely. To date, limited information is available on the safety of insects, and toxic elements are one of the potential hazards of concern. Therefore, we aimed to investigate the potential accumulation of cadmium, lead and arsenic in larvae of two insect species, Tenebrio molitor (yellow mealworm) and Hermetia illucens (black soldier fly), which seem to hold potential as a source of food or feed. An experiment was designed with 14 treatments, each in triplicate, per insect species. Twelve treatments used feed that was spiked with cadmium, lead or arsenic at 0.5, 1 and 2 times the respective maximum allowable levels (ML) in complete feed, as established by the European Commission (EC). Two of the 14 treatments consisted of controls, using non-spiked feed. All insects per container (replicate) were harvested when the first larva in that container had completed its larval stage. Development time, survival rates and fresh weights were similar over all treatments, except for development time and total live weight of the half of the maximum limit treatment for cadmium of the black soldier fly. Bioaccumulation (bioaccumulation factor > 1) was seen in all treatments (including two controls) for lead and cadmium in black soldier fly larvae, and for the three arsenic treatments in the yellow mealworm larvae. In the three cadmium treatments, concentrations of cadmium in black soldier fly larvae are higher than the current EC maximum limit for feed materials. The same was seen for the 1.0 and 2.0 ML treatments of arsenic in the yellow mealworm larvae. From this study, it can be concluded that if insects are used as feed materials, the maximum limits of these elements in complete feed should be revised per insect species.
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.
Interest in the use of insects for animal feed applications is increasing due to the potential for more efficient production of protein and other nutrients compared to other more traditional sources. This review provides a brief overview of the potential of insects to provide efficient, sustainable nutrition for animal species, from commercially farmed animals, to pets and to exotic animals housed for conservation efforts.
1. The aim of the present study was to investigate the effect of partial (50%) or total replacement of soybean oil (SO) by black soldier fly larvae (BSFL) fat on the growth performance, coefficients of apparent nutrient digestibility, selected internal organ weights and length, pancreatic enzyme activity and gastrointestinal tract (GIT) microecology modulation, as well as microbiota activity, physiological and immunological responses in young turkey poults.
2. A total of 216, seven day old female turkeys (BUT 6) were randomly distributed to three dietary treatments using six replicate pens per group with 12 birds per pen. The following design of the trial was applied: SO 100% soybean oil; BSFL50 a 50/50 combination of SO and BSFL fat; or 100% BSFL fat (total replacement of SO).
3. The use of BSFL fat did not affect the growth performance, nutrient digestibility, GIT morphology, or quality of the breast and thigh muscles. However, reduced trypsin activity was noticed in the BSFL100 group, but this had no effect on digestibility. Total replacement of SO reduced proliferation of potentially pathogenic bacteria, i.e., Enterobacteriaceae spp., as well as decreasing levels of IL-6, while partial substitution lowered the TNF-α concentration.
4. The replacement of commonly used SO by BSFL fat can be successfully applied in young turkey poult nutrition. BSFL fat may be considered an antimicrobial agent and support immune responses.
Edible insects such as black soldier fly larvae (BSFL) are alternative protein sources for animal feeds due to their high-protein content and potential low environmental footprint. However, protein quality and AA content may vary across insect species and age. Our objective was to determine the effects of age on nutrient and AA digestibility of BSFL intended for use in pet foods using the precision-fed cecectomized rooster assay. All animal procedures were approved by the University of Illinois Institutional Animal Care and Use Committee prior to experimentation. Twenty-four cecectomized roosters (four roosters per substrate) were randomly assigned to test substrates [BSFL0 = day 0 (day of hatch); BSFL11 = day 11; BSFL14 = day 14; BSFL18 = day 18; BSFL23 = day 23; BSFL29 = day 29]. After 24 h of feed withdrawal, roosters were tube-fed 20 g of test substrates. Following crop intubation, excreta were collected for 48 h. Endogenous corrections for AA were made using five additional cecectomized roosters. All data were analyzed using a completely randomized design and the GLM procedure of SAS 9.4. DM and OM digestibilities were not different among substrates, but acid-hydrolyzed fat digestibility tended to be greater (P < 0.10) for BSFL23 and BSFL29 than BSFL14 and BSFL18. Although all substrates had a high digestibility, BSFL0 and BSFL11 had the lowest (P < 0.05) digestibilities for most indispensable and dispensable AA. Digestible indispensable AA score (DIAAS)-like values were calculated to determine protein quality according to AAFCO nutrient profiles and NRC recommended allowances for dogs and cats. In general, BSFL18 had the highest, and BSFL11 had the lowest DIAAS-like values for most indispensable AA. Threonine, methionine, and tryptophan were often the first-limiting AA. Our results suggest that BSFL are a high-quality protein and AA source, but that age can affect the AA digestibility and protein quality of this alternative protein source.
Black soldier fly larvae (BSFL; Hermetia illucens) are a suitable protein source for poultry. However the effect of live BSFL supplementation on growth performance and behaviour has never been demonstrated and quantified in turkeys. Wild turkeys eat insects during the first two weeks of life which is in contrast with commercially fed crumbs or pellets. Damaging pecking behaviour is a severe problem in turkeys. More lively diets may improve natural behaviour and decrease damaging pecking behaviour. The aim of the experiment was to stimulate natural behaviour of young non-beak treated turkeys by supply of live BSFL to avoid damaging pecking behaviour. Two treatments with seven replicates were studied in 14 floor pens (1.5 m ² /pen and 20 turkeys per pen) from 0 to 35 days of age. Control groups were fed commercial diets and BSFL groups received live BSFL. The daily BSFL intake was calculated to be 10% of the expected daily feed intake (based on fresh weight) and dietary nutrient composition was adjusted in a way that control and BSFL groups were fed iso-nutritious. Daily feed intake and body weight gain of BSFL groups were significantly higher compared to control groups resulting in a significantly higher body weight at five weeks of age (2,190 vs 2,015 g; P=0.003) and a significantly lower feed conversion ratio. In the first week there was a tendency for more foraging related behaviour for the BSFL groups, but in the third and fifth week BSFL groups showed less foraging related behaviour compared to control groups. Provision of BSFL reduced aggressive pecking directed at the back and tail base at 5 weeks of age. Although the incidence of feather and skin damage was low, this type of damage tended to be lower in the BSFL groups.
Injury of the insect body wall, which enables environmental microorganisms to invade into insect tissues, induces innate immune responses including the induction of antimicrobial peptides (AMPs) in flies and silkworms. Here, house fly (Musca domestica) larvae and pupae were injured using a needle and the effects on the expression of genes encoding AMPs were examined. The expression of AMP genes including defensin, attacin, diptericin, and sarcotoxin II dramatically increased in both larvae and pupae after injury of the body wall, indicating that innate immune responses were induced. Furthermore, the injury-dependent expression of AMP genes was examined in larval tissues including fat bodies, hemocytes, salivary glands, and digestive tracts. Injury-dependent AMP gene expression was observed in salivary glands, hemocytes, and fat bodies, but not in digestive tracts. The degree of the transcriptional induction of each gene differed among tissues, suggesting that their expression is governed by complex regulatory machinery and that AMPs have tissue-specific functions. To further examine the properties of the AMPs, we examined the antimicrobial activities of partial synthetic peptides corresponding to portions of the predicted AMP proteins deduced from the AMP genes. A synthetic peptide exhibited antimicrobial activity, indicating that these injury-inducible genes are potential medicinal resources.
Given probable the increment in the nutritional needs of both humans and animals, animal production will have increased dramatically by 2050. Insect meals could be an alternative protein source for livestock, and they would also be able to reduce the environmental problems related to intensive animal production system. The aim of this study was to evaluate productive performance, blood analysis, nutrient digestibility, and changes in the internal organs of laying hens fed Hermetia illucens larvae meal (HI) at two different levels in substitution (25 or 50%) of soybean meal (SBM). A total of 162 Hy-line Brown hens (sixteen weeks old) were equally divided into three experimental groups and fed isoprotein and isoenergetic diets. Egg weight, feed intake, and feed conversion rate were not affected by the soybean meal substitution at both inclusion levels of insect meal. Egg mass was positively affected by the insect meal diets, as was the lay percentage, although only at the lowest inclusion level. Dry matter, organic matter, and crude protein digestibility coefficients were lower for the HI50 diet, probably due to the negative effect of chitin. A reduction in serum cholesterol and triglycerides was observed in both insect-meal fed groups, while serum globulin level increased only at the highest level of insect meal inclusion, and, consequently, the albumin to globulin ratio decreased. Overall, a protein replacement of 25% with an insect meal from Hermetia illucens larvae in the diet of laying hens seems to be more suitable and closer to the optimal level.
Edible insects are expected to become an important nutrient source for animals and humans in the Western world in the near future. However, before insects can be put on the market, the safety of their use for feed and food is warranted. This literature study was prepared to provide an overview of the actual knowledge of possible food safety hazards, including chemical, microbiological, and allergenic agents and prions, to human and animal health upon the use of insects for food and feed, and to highlight data gaps and suggest the way forward. From the data available, heavy metals of concern are cadmium in black soldier fly and arsenic in yellow mealworm larvae. Investigated mycotoxins do not seem to accumulate. Residues of pesticides, veterinary drugs, and hormones, as well as dioxins and PCBs, are sometimes found in insects. Contamination of insects with pathogens to human health is a consequence of a combination of the substrates used and the farming and processing steps applied. Insects harbor a wide variety of microorganisms, and some human pathogenic bacteria may be present. In addition, insects may harbor and transmit parasites. There is no evidence so far insects may harbor pathogenic viruses or prions, but they may act as vectors. Insects and insect‐derived products may have allergenic potential. In this review, evidence on some safety aspects is displayed, and data gaps are identified. Recommendations are given for future research to fill the most relevant data gaps.
Background
There is a growing interest in the use of insects in poultry, swine and aquaculture feed and pet food applications. All insects produce chitin‐based exoskeletons. Concerning the chitin content, precise determination in agricultural applications is crucial because it has favorable functional properties, but is also difficult to digest for some species of livestock. Three measurement methods were compared to determine the most reliable method for chitin content determination in different insects and selected H. illucens products: Acid detergent fiber (ADF) provides the fiber content, the acid detergent lignin (ADL) additionally considers the catecholic compounds. Acetyl group measurement relates the acetate to the chitin content.
Results
The highest chitin value via ADF measurement was determined for the T. molitor larvae (155 g kg‐1). Chitin values higher than 200 g kg‐1 revealed that H. illucens residues are a valuable source for chitin. For the larval exoskeletons, a chitin content for all measurement methods of more than 350 g kg‐1 was determined. In general, the ADF measurement is about 5% higher than the ADF‐ADL and acetyl measurements. ADF‐ADL and acetyl group determination are approximately equivalent measurement methods.
Conclusion
According to statistical analysis, ADF‐ADL represents a compromise between accuracy and equipment demand and is a suitable method to determine the chitin content of both, insects and their residues.
Background:
The black soldier fly (Hermetia illucens) is one of the most promising insect species for the use in animal feed. However, studies that investigate feed and food safety aspects of using black soldier fly as feed are scarce. In this study, we fed black soldier fly larvae feeding media enriched with seaweed, which contains naturally high concentrations of heavy metals and arsenic. The aim of this study was to investigate the potential transfer of such undesirable substances from the feeding media to the larvae.
Results:
The larvae accumulated cadmium, lead, mercury and arsenic. Concentrations of these elements in the larvae increased when more seaweed was added to the feeding media. The highest retention was seen for cadmium (up to 93 %) and the lowest for total arsenic (up to 22 %). When seaweed inclusion exceeded 20 % in the media, this resulted in larval concentrations of cadmium and total arsenic above the current European Union maximum levels for these elements in complete feed.
Conclusion:
Our results confirm that insect larvae can accumulate heavy metals and arsenic when present in the feeding media. A broader understanding of the occurrence of these undesirable substances in processed larvae products is needed to assess feed and food safety.
To investigate the effect of two insect meals (from Hermetia illucens, HI and Tenebrio molitor, TM larvae) on productive performance and blood profiles of Barbary partridge, ninety, seven days old partridges were divided into 5 groups (6 replicates, 3 partridges/replicate). Up to 64 d, the groups fed 5 isoproteic and isoenergetic diets: the control fed a corn-soybean meal diet (SBM group); in TM25 and TM50 groups the 25 and 50% of SBM proteins were substituted by the protein from TM, respectively; in HI25 and HI50 groups the 25 and 50% of SBM were substituted by the protein from HI, respectively. The birds fed TM25 and both the HI levels reached a higher (P < 0.01) live weight at 64 d than the control. Considering the entire experimental period the TM groups had a more favorable FCR than SBM. The carcass weights of all the insect groups were higher (P < 0.01) than the control. The weight of the full digestive tract in SBM group was the highest (P < 0.01). The caecal weight, the intestinal and caecal length were the highest (P < 0.01) in the SBM group. The SBM group the highest value of albumin/globulin (P < 0.01) and creatinine (P < 0.05). TM seems to be more effective than HI in improving FCR. The reduced albumin/globulin ratio in the insect meal fed groups could be ascribed to the chitin content and this result was not affected by the amount of chitin intake, suggesting that also the lowest values are able to express their potential effects in partridges.
This paper presents the current situation of the global poultry sector and future trends, and discusses the challenges the sector is facing, with particular emphasis on four areas: food security, social challenges (poverty alleviation and equity), health (animal and human) and environment (natural resources and climate change). Poultry makes a substantial contribution to food security and nutrition, providing energy, protein, and essential micro-nutrients to humans, with short production cycles and the ability to convert a wide range of agri-food by-products and wastes into meat and eggs edible by humans. Poultry is the fastest growing agricultural sub-sector, especially in developing countries. The global poultry sector is expected to continue to grow as demand for meat and eggs is driven by growing populations, rising incomes and urbanisation. In this context, the sector is facing unprecedented challenges. Particularly for small holders and the poor, both in rural and urban areas, poultry is a major asset and key to poverty alleviation, providing income and market participation. Birds can be sold in times of crisis and act as household insurance. But the growing market is essentially benefiting large scale operations and access to market is critical for small holders. However, poultry represent a threat to human health, especially as a vector of infectious diseases and because of its role in antimicrobial resistance. Furthermore, poultry has a significant impact on the environment and is a large consumer of natural resources. While the sector is usually seen as efficient in converting natural resources into edible products, it uses large amounts of land, water and nutrients for the production of feed materials and contributes to climate change, mainly through feed production, and air and water pollution.