Black Soldier Fly (BSF) Larvae as alternative and affordable solution of protein for Backyard Poultry , Waste Management, and a Circular Bio-Economy
Currently, poultry producers in developing countries are facing problems of high cost
and poor quality of poultry feed. Insects are one of the potential protein sources for
poultry feed. The use of insects as poultry feed is not in direct competition with human
for food consumption. The objective of this paper is to review the current work related
to the use of Black Soldier Fly (BSF) larvae meal as an alternative protein source in
poultry feeding. Black soldier fly is a harmless insect serving as an alternative protein
source in animal feeding and in the disposal of organic wastes, by-products, and side
streams. The results of numerous studies showed that BSF larvae meal could safely
and economically be used as protein concentrate in poultry ration. BSF larva contains
high calcium and phosphorus and contains about 35-42% crude protein with
biological value and comparable amino acid profile to that of soybean meal (SBM).
The lysine and methionine contents of BSF larva are comparable to that of meat meal.
Recent evidence suggests that the nutritional value of BSF larva is comparable to that
of fish meal. Many authors suggested that BSF larvae meal could replace a fish meal
or upgrade the nutritive value of SBM in broiler diets without any adverse effect on the
production performance. The use of BSF larvae in layers diet resulted in enhanced
laying performance and egg qualities. Generally, all the available literature confirms
the feasibility of total or partial replacement of fish meal and SBM with BSF larvae meal.
Hermetia illucens L., also known as the Black Soldier Fly (BSF), is an insect that is increasingly being utilized worldwide. One of its recently discovered benefits is its potential as an edible insect. BSF larvae are efficient and fast bioconversion agents capable of recycling a broad array of organic substrates (Bonelli et al 2020). The number of studies on bioconversion based on BSF larvae is growing, as they can help solve the issue of reducing and reusing food and industrial waste (Ceccotti et al 2022). By transforming organic food waste into high-value animal products, BSF larvae contribute to the development of organic waste management solutions (Cappellozza et al 2019).
Black Soldier Fly (BSF) larvae reproduce rapidly in substrates such as chicken manure, poultry offal, and other organic waste. The development and biomass composition of BSF larvae might be influenced by their feed source, particularly the ratio of protein to carbohydrate (Abduh et al 2022). High substrate protein concentration has been found to affect the crude protein content of BSF larval biomass (Barragan-Fonseca et al 2017). Numerous studies have been conducted on the development of substrates for rearing BSF larvae for various purposes (Nguyen et al 2013; Jucker et al 2017; Cicilia and Susila 2018; Lalander et al 2019; Scala et al 2020; Gold et al 2020; Singh et al 2021; Abduh et al 2022).
The high cost of poultry rations has led to the exploration of cheaper alternative feedstocks with superior nutritional properties. Feed sourced from vegetable ingredients has been widely used as an alternative, but it faces several challenges, including a deficiency in essential amino acids such as lysine (Ahmad et al 2022). In the poultry industry, feed based on BSF larvae presents a compelling alternative to replace existing ingredients, which are not only expensive but also often compete with human consumption (Moula et al 2018). BSF larvae can produce approximately 40% protein, which is higher compared to some other alternative sources used in feed formulations (Bosch et al 2014; Ewald et al 2020) and they contain nearly all digestible proteins (Schiavone et al 2017).
BSF larvae, due to their high nutritional properties, can serve as a substitute for soybean and fish meals in poultry rations. However, there is limited information available on the impact of mixing chicken manure with tofu pulp on the performance of BSF larvae. We hypothesize that using a combination of chicken manure and tofu pulp as feed could enhance the performance of BSF larvae. Therefore, this study aims to examine the effect of different types of feed on the performance, biomass productivity, and bromatological composition of BSF larvae. Ultimately, these larvae have the potential, both nutritionally and economically, to address the issue of costly poultry feed.
Black soldier fly (BSF) larvae are attracting the attention of researchers and livestock industry as an alternative source of protein. These larvae can convert organic waste into protein for animal consumption, whilst also changing waste into a product that can be used, for example, as compost (Dortmans, 2017). Their use in animal feeding could be a step into carbon footprint reduction and sustainable agriculture (Van Huis, 2013). This article explores the process of rearing BSF larvae, its nutrient composition, as well as the factors affecting such composition.
Black Soldier Fly (BSF) farming in India represents a burgeoning sector with significant benefits for waste management and sustainable feed production. Given India’s demand for innovative solutions to waste and need for sustainable feed, BSF farming has gained notable attention.
Significance of BSF in Waste Management
BSF larvae are highly efficient in converting organic waste into valuable byproducts. In India, where urban waste management is a critical issue, BSF offer a viable solution. These larvae can consume a wide range of decomposing organic matter, thus reducing the overall waste volume. The process not only mitigates the problem of excess waste but also yields high-quality protein that can serve as feed in the aquaculture and poultry industries.
Current Status and Potential in India
The practice of BSF farming is in its developmental phase in India, but it holds immense potential given the country’s high organic waste output and increasing protein demand. Pioneering companies in India are beginning to establish commercial-scale operations that utilize BSF larvae to process organic waste. This approach is not only sustainable but also scalable, possibly addressing two of India’s pressing issues: waste management and the sustenance of a steadily rising demand for livestock and aquaculture feed.
How Do I Feed Them to Chickens?
You may be wondering why these insects are so healthy for fowl. While the adults aren’t generally fed to chickens, their larvae make an exciting, nutritious, and free supplement in your flock’s diet. Black soldier fly larvae are about 50 percent protein and a rich source of vital nutrients, such as calcium. Since protein is necessary for feather growth and egg production, it’s clear how beneficial these yummy treats are for hens. The extra calcium will help your flock lay better eggs, too.
There’s no exact percentage for how much of your flock’s diet is replaceable with black soldier fly larvae. Just make sure that your chickens are getting all the nutrients they need. You can start by replacing 10 percent of your flock’s regular grain, and increase from there. They’ll thank you! It’s always a good idea to consult your veterinarian as well.
To feed these insects to your flock, you have some options. You can:
- Feed the insects live
- Sacrifice the larvae by freezing them (thaw them before feeding)
- Dry the larvae for long-term storage
Each option has advantages. Feeding live insects is exciting and fun for your chickens because it lets them indulge in their natural behaviors. Our birds are omnivores; they evolved to forage and seek out tasty insects. Since we keep them cooped all day, they get a bit bored! Live insects break up the boredom and give your flock a bit of exercise.
Eventually, live black soldier fly larvae will pupate into adults. The mature black soldier flies will stop breeding as summer fades to fall, and you’ll have no more larvae to harvest until the following spring. If you don’t harvest and store some of the young, your steady supply will eventually dwindle.
Feeding dead black soldier fly larvae makes it easy to mix them with feed. It’s also easier to hold onto dead larvae for longer-term storage (either by freezing them or drying them). If you don’t want to keep the black soldier fly larvae in your freezer, you can dry them after they’ve died in the freezer. Use a solar oven or even a household oven to dry them for long-term storage. Another method to dry black soldier fly larvae is to microwave them, however, I’ve never personally tried that method.
Setting Up a BSF Farm
Setting up a Black Soldier Fly (BSF) farm in India requires meticulous planning regarding infrastructure, breeding conditions, and management. Here are the specifics on how to establish a sustainable and productive BSF farming operation.
Infrastructure Requirements
A BSF farm must have a dedicated space for breeding, rearing, and processing. This should include secure breeding areas, larval rearing containers, and a separate space for harvested larvae. Water sources for hydration and humidity control are critical. Additionally, facilities for feed storage and waste management are necessary. The initial startup costs will vary depending on scale and equipment.
- Breeding Area: minimum of 10 square meters
- Rearing Containers: moisture-resistant and scalable
- Processing Area: hygiene-centric design for larva processing
Optimal Conditions for Breeding
For Black Soldier Fly farming success, maintaining temperature and humidity within specific ranges is crucial. BSF larvae thrive in warm environments and the breeding area should be kept between 25°C to 30°C. Humidity, equally important, must be regulated at around 60% to 70% to encourage mating and egg-laying.
- Temperature: 25°C to 30°C for breeding consistency
- Humidity: 60% – 70% for optimal egg production
Farm Management Practices
Efficient farm management practices include regular monitoring of environmental parameters and adherence to sanitary protocols. Constant availability of nutrient-rich feed accelerates production and larval growth. The BSF lifecycle must be understood thoroughly to properly harvest at the pre-pupal stage, ensuring the highest quality and yield.
- Feed Management: High-quality, sustainable feed sources
- Lifecycle Monitoring: Accurate timing for harvesting larvae
- Sanitation: Routine cleaning to prevent diseases and pests
Feeding and Rearing of BSF Larvae
The success of black soldier fly (BSF) farming relies heavily on understanding their larvae’s nutritional needs and implementing effective rearing techniques. By ensuring proper feeding and rearing practices, farmers can achieve optimal larval growth and high-quality protein output.
Nutritional Needs and Diet
Black soldier fly larvae have a voracious appetite, allowing them to consume large quantities of organic waste. They thrive on a diet comprising waste streams like pre-consumer kitchen waste, poultry manure, and unused food by-products. The key to a nutrient-rich diet for the larvae is an appropriate balance of protein, nutrients, and moisture. Protein is essential for their growth, making up about 42% of the dry matter in larvae. Moisture content should be maintained around 60-70% for optimal larval development.
Efficiently converting waste into biomass, BSF larvae can reduce waste volume by up to 50-80%, promoting sustainable waste management. Utilizing this trait not only solves waste disposal issues but also supports the creation of a valuable feed source for animal nutrition. The nutritive value of BSF larvae makes them an excellent supplement in poultry feed.
Rearing Techniques
When it comes to rearing techniques, two key components to consider are the environmental conditions and the life cycle management of BSF. The farming area should be well-ventilated, with temperatures ranging between 27°C and 30°C, which are ideal for BSF larvae growth. Farmers need to pay attention to feed quality and accessibility, as it influences the growth rate and health of the larvae.
A two-stage rearing process is commonly employed. The first stage focuses on allowing the larvae to feed and grow to their optimum size. The second stage involves preparing mature larvae for pupation. During this phase, they are separated from the feeding medium and allowed to metamorphose into flies, completing the life cycle.
Adopting small-scale rearing practices can be an entry point for farmers looking to experiment with BSF farming. These practices offer guidance on establishing BSF farms and convey the simplicity and efficiency of small-scale operations, as detailed in strategies for small-scale rearing of BSF larvae.
Harvesting and Processing
Harvesting and processing are vital steps in the black soldier fly farming cycle, ensuring proper separation of larvae and conversion of their body mass into high-quality end products like protein, oil, and fats.
Collection and Separation of Larvae
Once black soldier fly larvae have reached their optimal size, harvesting begins. Farmers utilize methods that prompt larvae to self-harvest, typically moving towards collection points due to their instinct to find a dry place to pupate. Efficient separation techniques are then applied to isolate the larvae from residual substrate. Consistency in larval size and body mass determines the quality of the harvest, which can directly impact the processing phase.
Processing into End Products
The black soldier fly larvae, rich in protein and fats, undergo processing that involves drying and mechanical separation to extract oil and prepare the dried larvae for further applications. Dried larvae are milled into a fine powder, commonly used as an additive in animal feed due to its high nutrient content. The extracted oil can be utilized for biofuel, while the remaining body mass is used in agriculture as a high-quality soil amendment.
Applications of BSF in Animal Nutrition
Black Soldier Fly (BSF) larvae, when processed into insect meal, provide a highly nutritious and sustainable ingredient for animal feed. They are particularly valued for their high protein content, essential amino acids, and fats, making them an ideal component in the diet of various animals.
Inclusion in Poultry Diets
Poultry feed formulation has seen a significant shift with the inclusion of Black Soldier Fly larvae meal. The larvae’s rich protein and iron content contribute to the growth and health of poultry. Studies suggest that even a partial replacement of traditional feed with insect meal can result in comparable, if not improved, poultry performance.
Use in Aquaculture Feeds
Aquaculture industries opt for BSF meal as a component in aquafeed to enhance the nutritional profile of feeds for fish and other aquatic animals. The incorporation of BSF meal is known to support better growth rates, feed conversion ratios, and health due to its fats and amino acids that are vital for aquatic species.
Contribution to Livestock and Pet Nutrition
The usage of BSF in livestock and pet food has been gaining traction. As a source of quality protein and essential fats, BSF meal offers an alternative to traditional feed ingredients and helps in reducing the dependence on conventional sources like soybean meal and fishmeal, thereby addressing both sustainability and nutritional needs.
Environmental Benefits and Sustainability
Black soldier fly farming represents a transformative step in waste management, showcasing a sustainable loop that benefits the environment. This process effectively reduces organic waste and bolsters the circular economy, situated as a practical ecological innovation in India.
Reduction of Organic Waste
Black soldier fly larvae (BSFL) exhibit a remarkable capacity to decompose organic matter, turning it into valuable biomass. They reduce the volume and mass of waste, minimizing the ecological footprint of waste disposal. Research indicates that BSFL can help reduce the overall environmental impact of organic waste, which is a crucial step in sustainable waste management practices.
Contribution to the Circular Economy
The application of BSFL in organic waste processing aids in the creation of a circular economy model. These larvae not only consume waste but also produce valuable by-products, such as protein-rich biomass for animal feed and frass — a nutrient-rich compost. By transforming organic waste into resources, black soldier fly farming closes the loop, reflecting a genuine sustainable measure with economic and ecological value.
Commercial and Economic Aspects
The commercial and economic landscape for black soldier fly farming in India is characterized by burgeoning market demand and the potential for scalable economic viability. This sector is witnessing a rise in the number of companies entering the fray, instigated by the sustainability and innovation that black soldier fly larvae offer for waste management and as a protein source for animal feed.
Market Demand and Potential
The Indian market has shown a growing demand for sustainable and circular economy practices, with black soldier fly (BSF) farming emerging as a significant part of this trend. Companies are recognizing that BSF larvae can convert organic waste into high-quality protein, making it a compelling solution for both waste management and animal feed production. As agriculture and fish farming integrate BSF larvae into their operations, the market potential is substantial. Studies such as the one by Rocket Skills examine the utility of BSF larvae in making agricultural land fertile and providing feed for livestock, indicating a comprehensive role in macro and micro agriculture management practices.
Economic Viability and Scaling
Economic assessments indicate that black soldier fly farming can be economically viable for small to medium farmers in India. The properties of BSF larvae as a protein-rich feed alternative are being utilized to support fish farming practices, creating a synergistic approach to farm management. This innovation in farming practices is not only sustainable but also reduces reliance on traditional feedstocks, which can be financially and environmentally costly. According to Academic OUP, BSF provides an essential alternative protein source that can be locally produced, enhancing the viability for small-holder farmers. Distribution and production challenges persist, but the evolving nature of the market suggests clear pathways for scaling up production to meet the demand effectively.
Through these agile practices, BSF farming supports a circular and sustainable model, demonstrating a profound potential to reshape the agricultural and aquacultural landscapes in India.
Challenges and Opportunities
In the burgeoning industry of black soldier fly (BSF) farming in India, stakeholders are met with an intricate tapestry of challenges and opportunities. These range from navigating through regulatory frameworks to leveraging advancements in research and development that could herald a new era for sustainable animal feed and waste management solutions.
Regulatory Hurdles and Government Policies
Challenges:
- Complex Licensing Processes: Entrepreneurs in India face a labyrinthine process to obtain the necessary licenses for BSF farming, hindering the pace of industry growth.
- Lack of Specific Guidelines: There’s an absence of targeted regulations for insect farming, which can lead to a precarious legal framework for operators in the sector.
Opportunities:
- Policy Support: The government has the opportunity to foster this nascent industry by formulating clear guidelines and supporting insect farming under its agribusiness initiatives.
- Subsidies and Incentives: Introducing financial incentives could encourage more farmers and businesses to venture into BSF farming.
Research, Development, and Innovations in BSF Farming
Challenges:
- Limited Local Studies: There’s a scarcity of localized research on BSF farming, which is crucial for understanding regional implications on production and usage.
Opportunities:
- Innovation in By-products: India has the potential to become a leader in developing BSF by-products for industries such as cosmetics and fertilizers, fostered by dedicated R&D initiatives.
- Collaborations with Academia: Partnerships between businesses and academic institutions can drive innovation, making the BSF industry more robust and adaptable to society’s needs.
Through addressing these regulatory and R&D challenges, India can unlock myriad opportunities within the BSF farming sector, leading to sustainable societal and economic benefits.
Case Studies and Successful Models
This section explores how certain enterprises have effectively harnessed the potential of black soldier fly (BSF) farming, transforming waste into a sustainable source of animal feed within the Indian context.
Notable Startups and Companies
- EntoGreen is a pioneer in India, leading the charge in BSF farming by converting organic waste into high-quality feed for poultry and aquaculture.
- Protenga is an Asian startup with operations in India that has developed a sophisticated system for BSF rearing and processing, showcasing a successful model in the insect protein sector.
Impact and Growth Stories
- In a groundbreaking case study, the Indian Journal of Animal Sciences documented a BSF startup that has repurposed tons of food waste, substantially reducing the environmental burden while simultaneously generating feed for local farms.
- EnviroFlight, while not based in Asia, exemplifies growth in the sector, inspiring several Indian startups to adopt BSF in their animal husbandry practices, scaling up sustainably to meet the growing protein demand.
Black soldier fly (BSF) farming in India has emerged as a significant contributor to sustainable development and food security. Black soldier fly larvae have the remarkable ability to convert organic waste into high-quality protein, making them a valuable resource for both waste management and animal feed production.
The utilization of BSF in waste processing transforms organic waste into nutrient-rich compost, enriching agricultural soils. The protein derived from BSFL offers an eco-friendly and economically viable alternative to traditional animal feed sources, alleviating pressure on overharvested fish populations and reducing reliance on water-intensive plant protein.
Future prospects for black soldier fly farming are promising due to its low environmental impact and the increasing demand for sustainable feed options. Pilot projects and studies have highlighted the BSF’s potential, fostering an environment ripe for expansion and innovation. As the recognition of BSF benefits grows, India is poised to advance in the domains of waste management and protein production.
The practice aligns with the global goals of sustainable development, offering a circular solution to organic waste disposal and contributing positively to food security through the provision of cost-effective feed for livestock. Adopting black soldier fly farming on a broader scale can pave the way for a greener, more resilient future.
In summary, black soldier fly farming holds significant potential for India’s sustainable agricultural practices, promising to play an integral role in shaping a more food-secure and environmentally responsible tomorrow.
Biology / Lifecycle of Black Soldier Fly
The BSF has five stages in its lifecycle: egg, larvae, prepupae, pupae, and adult. The estimated life cycle of BSF is 40 days but this length differs depending upon the environmental conditions present and the nutrition provided (Alvarez, 2012). Eggs are usually creamy yellow in color and take 4 days to incubate and hatch under optimum conditions of around 20°C to 30°C (Newton 2015). Immediately after hatching, BSF larvae have a dull, whitish color and try to hide away from light due to their photophobic nature (Newton, 2015). Larvae are a very voracious consumer of organic matter and can grow rapidly. The larvae spend most of their life feeding on food and manure wastes and rapidly turn them into fat, protein, and calcium. These nutrients are utilized by larvae to morph into pupae, and further, into adults (Newton et al., 2005).
The optimal temperatures of black soldier fly for efficient utilization of feed ranges from 27 to 330C (Alvarez, 2012). Lower temperatures are most likely tolerable because feeding action and metabolism of the larvae will generate some heat which allows their development in colder climates (Newton, 2015). With optimum temperatures, larvae will reach full size (20 to 25mm) in about 4 weeks but can take from 2-4 months if temperature and enough feed are not available ( Newton, 2015). Larvae can tolerate and thrive at densities up to almost 3lb per sq. ft. (14kg/m2) (Burtle et al., 2012). Optimal moisture content for the feed ranges from 60% to 90% and is very important for the development of BSF.
When the BSF larvae grow into full size (½-inch-long grubs) (Burtle et al. 2012), larvae stop feeding, they become dark and their skin becomes harder. This is the pre-pupa stage, at this point, they start searching for a dry and dark place other than a feed source to pupate and transform into an adult (Newton, 2015). It is supposed that migrating larvae leave chemical trails so that other maggots follow creating a migration path. Along with drier conditions, the pupation site also requires ambient humidity levels of approximately 60% to emerging as adults. Pupation can last 5 to 7 days depend on temperature and ambient humidity. Adults emerge after 10-14 days at 27-36oC (Myers et al., 2008) from their pupae cases. The main purpose of adults in the life cycle is to mate and lay eggs. The adults do not feed but drink water or other liquids if available and rely on the fats stored from the larval stage for their life activity (Newton, 2015).
Adults live and mate two days after emerging from the pupal stage (Myers et al., 2008). Female oviposit into dry cracks and crevices near larval habitat (Newton et al. 2005) two days after copulation. A temperature of 25°C-35°C (Newton, 2015) and ambient light plays a vital role to initiate mating for adult flies, as it is found in the studies that mating levels of adults were highest under natural sunlight. Furman et al. (1959) stated that BSF mating begins in the air with aerial questing after stimulation by light (Alvarez, 2012). The adult flies are photophilic and require strong daylight spectra as well as temperatures between 25°C and 35°C to encourage mating to occur.
Production Systems of Black Soldier Fly and organic substrates
Several methods of rearing BSF have been developed till now. The designs depend on the type of substrate provided for optimal growth and development of BSF. In this type of production system, a conveyor belt made for the collection of waste is designed in such a way that manure solids were collected in the conveyer belt whereas urine plus excess water were drained off the sides of the belt into collection gutters. Then the collected manure solids were delivered to the larval culture basin. The larval culture basin contained 90,000 to 100,000mixed aged larvae/m2. A 35o ramp along opposing walls of the manure pit is constructed to facilitate the migration of the prepupae to the gutter at the top. This gutter then allows prepupae to pass in collection containers. During this, a portion of the prepupae is saved with the purpose to support the adult soldier fly colony. Eggs from the adult colony are used to maintain larval densities sufficient to digest the manure. The remaining prepupae are frozen until the composite is dried for feed preparation (Sheppard, 2002).
Different types of organic waste have been used for farming back soldier fly larvae in confinement. Major BSFL growth parameters such as development time, feed conversion efficiency, mortality, larvae weight, and nutrient composition are strongly affected by the growth substrate (Zheng et al., 2012). Therefore the commercial-scale application of the technology will demand the usage of substrates that can yield quality larvae within a short duration and reduce losses through mortality is necessary. Due to the larvae consuming a wide range of organics, the full range of substrates for rearing BSFL especially for biomass production on a commercial scale are still largely undetermined (Leek, 2017). Organic waste materials are also highly heterogeneous in nature and variable in terms of moisture and nutrient content and therefore generalized applications of findings are almost impossible (Holmes et al., 2012).
Nguyen et al. (2015) compared the development rate, size, and mortality of BSFL fed on poultry, feed, pig manure, fish renderings, and kitchen food waste and reported that larvae fed on kitchen food waste had the fastest growth, heaviest biomass, and yields attributed to higher calorie content. Kalova and Borkovcova (2013) fed BSF larvae 14 different waste types over a 14 day period and only four of the waste streams resulted in adult flies during this period among them post-consumer food waste suggesting that these diets were the most suited to larval development.
Social, Economic and Environmental Benefits of Black Soldier Fly
Biomass conversion
Several researchers have shown that BSFL is effective at reducing animal manure and organic waste materials by converting them into a protein and fat-rich biomass suitable for various purposes, including animal feeding, biodiesel, and chitin production (van Huis et al., 2013). Kim et al. (2011) reported that BSF was able to consume and digest raw organic waste materials (manure, kitchen waste, abattoir waste: blood and offal’s) more rapidly and resourcefully than the house fly(Musca domestica). Newton et al. (2005) fed a total of 4500 larvae fresh swine manure to BSFL and the larvae converted 68kg dry weight of manure into 41.6kg dry weight residue and 26.2kg of prepupae. The author also recorded BSFL reduced 55kg of fresh manure, dry matter, to 24kg of residue, dry matter, within 14 days and the manure was reduced by 56%, with the residue having no objectionable odor. Sheppard et al. (1994) fed BSFL approximately 5.2 tons of fresh chicken manure and the manure was reduced to approximately 2.6 tons of residue, yielding 242kg of prepupae, with a mean weight of 0.22g. The authors also reported that BSFL reduced the manure by up to 50%, while at the same time eliminating house fly breeding. The larvae were fed different quantities of manure of waste materials 1.5 or 4.6 kg each day, with the new food either mixed in or placed on the surface (Diener et al., 2011). There is a good opportunity to utilize these flies for bioconversion considering the fact that approximately 1.3 billion tons offood is wasted from the food produced each year in the world (Gustavsson et al., 2011).
Odor and pollution reduction
Odor and pollution reduction are other benefits derived from BSF. This is accomplished by their abundant densities on waste material combined with their avid appetite, causing the waste material to be processed at a fast rate, while the larvae are processing this waste; they aerate and dry the material suppressing bacterial growth. The larvae modify the microflora of manure, potentially reducing harmful bacteria such as Escherichia coli 0157:H7 and Salmonella enterica (van Huis et al., 2013). The BSF larvae reduce the nutrient concentration and the amount of manure residue, leading to a reduction in the amount of pollution, possibly by 50-60% or more (Newton et al., 2005) and causing it to be less favorable to the house fly larvae. The combination of all these characteristics causes a reduction in odors and pollution (Diener et al., 2011).
Housefly control
The common housefly (M. domestica) tends to come into more contact with humans for a number of reasons. The common housefly feeds throughout its life due to its physiology of having functional feeding parts. This causes the fly to always be on the lookout for edible organic matter, such as human food, making the interaction between the fly and humans more common. The BSF’s physiological traits of having no functional feeding parts cause it to have no attraction to homes, consequently reducing any pest-like behavior and living its life apart from humans (Barry, 2004). However, the BSF has a strong ability to reduce the number of house flies by preventing the house fly from ovipositing (the act of depositing eggs). The reduction of house flies will be a large benefit as they are prominent disease vectors, adding to the importance of their population control. The ability of colonization by BSF was reported by Sheppard et al. (1994) who discovered that BSF had the ability to colonize poultry and pig manure causing a reduction in common housefly populations by 94-100%.
Chitin benefit
Apart from having a desirable (soluble) protein content, insect species also contain high amounts of chitin, which is the main constituent in the insect exoskeleton. Chitin is a non-toxic, biodegradable linear polymer. Recent studies confirmed that chitin has effects on innate and adaptive immuneresponse, including the ability to recruit and activate innate immune cells and induce cytokine and chemokine production via a variety of cell surface receptors including macrophage mannose receptor, toll-like receptor 2 (TLR-2), and Dectin-1(Lee et al., 2008).
Nutritional Profile of Black Soldier Fly Larvae
The nutritional profiles of BSF larvae as animal feed sources were reported by various authors. The DM content of fresh larvae is quite high (35-45%), which makes them easier and less costly to dehydrate than other fresh by-products (Newton et al., 2008). Maurer et al. (2016) reported that dried full-fat BSF larvae meal contained 41.5% CP, 26.5% EE, 4.3% ash, 0.80% Ca, 0.50% P, 0.08% Na and 0.33% chloride while dried partly-defatted BSF larvae meal consisted 59.0% CP, 11.0% EE, 5.0% ash, 0.98% Ca, 0.63% P, 0.08% Na and 0.28% chloride. The result showed that partly-defatted BSF larvae have better CP, ash, Ca, and P contents than full-fat ones. Newton et al. (2005) found protein levels of 43.2% of BSF pre-pupae reared on pig manure while a value of 42.1% was found when reared on poultry manure (Newton et al., 1977). Relatively, similar protein content (43.6%) was reported by St-Hilaire et al. (2007) when reared on pig manure. Results confirmed by Oonincx et al. (2015) showed CP values ranging between 38% and 46%, and fat values between 21% and 35%. Crude protein and fat values of larvae in a trial conducted by Driemeyer (2016) were 35.9% and 48.1%, respectively. Crude protein content in larvae increased just after hatching, and then it gradually decreased from 4–12 days of larval development, with a minimum concentration of 38% crude protein (CP) at larval phase followed by a further increase of 39.2% in mature larvae on day 14 (Sauvant et al., 2004).The various values of CP contents of BSF reported by authors were due to different types of diet given to the fly and life stage of the fly.
According to Newton et al. (1977), the fat content of BSF larvae was 28.0% on pig manure, 35%on cattle manure, and 34.8% on poultry manure. The lipids of larvae fed on cow manure contained21% of lauric acid, 16% of palmitic acid, 32% of oleic acid, and 0.2% of omega-3 fatty acids, while these proportions were, respectively 43%, 11%, 12%, and 3% for larvae fed 50% fish offal and 50% cow manure (Makkar et al., 2014).
The BSF larva is a better or comparable amino acid profile to that of soybean meal (SBM) (Tran et al., 2015). The lysine and methionine content of BSF larvae proteins are comparable to that of meat meal (Ravindran et al., 1999). Cullere et al. (2016) reported that the most abundant essential amino acids were valine and leucine, whereas alanine and glutamic acid were rich in defatted BSF larvae meal. The content of amino acids in BSF varies throughout their lifespan and appears to be related to its CP content as the highest level of amino acids contents was mostly expressed in the early stages of larval development then gradually decreased. In dry matter (DM), the adult stage of larvae was characterized by the highest content of amino acids (g/kg) (Liu et al., 2017).
Generally, black soldier fly larvae meal CP are comparable to others insect meals and to that of soybean meal but slightly lower than that in fish meal.
The BSF larva is high in calcium and phosphorus (Newton et al., 2005). The ash content varied between different samples of BSF pre-pupae depending on their feed substrate. Newton et al. (2005) found an ash content of 16.6% when the BSF pre-pupae were reared on pig manure and 14.6% on poultry manure (Newton et al., 1977). Moreover, an ash content of 15.5% was reported by St-Hilaireet al. (2007) when pre-pupae were fed pig manure. However, a low ash value of 7.8% was recorded by Driemeyer (2016) when BSF pre-pupae were reared on pig manure.
Table 1: Comparison of black soldier fly larvae with some insects’ meals and soybean meal and fish meal
| Types of insect | Chemical composition | References | ||||
| CP | CF | EE | Ash | GE | ||
| Mealworm | 52.8 | – | 36.1 | 3.1 | 26.8 | Finke, 2002 |
| House cricket | 63.3 | – | 17.3 | 5.6 | – | Finke, 2002 |
| Black Solder Fly Larvae | 42.1 | 8 | 26 | 20.6 | – | St-Hilaire et al., 2007 |
| Housefly maggot Meal | 50.4 | 5.7 | 18.9 | 10.1 | 22.9 | Adesina et al., 2011 |
| House fly pupae | 70.8 | 15.7 | 15.5 | 7.7 | 24.3 | Pretorius, 2011 |
| Locust or grasshopper meal | 57.3 | 8.5 | 8.5 | 6.6 | 21.8 | Alegbeleye et al., 2012 |
| SWP meal (non- defatted) | 60.7 | 3.9 | 25.7 | 5.8 | 25.8 | Jintasataporn, 2012 |
| Fish meal | 70.6 | _ | 9.9 | – | – | FAO, 2011 |
| Soybean meal | 51.8 | – | 2.0 | – | – | FAO, 2011 |
CF=crude fiber; CP= crude protein; EE= ether extract; GE= gross energy, SWP=silkworm pupae
Table 2. Amino acid compositions (g/16 g nitrogen) of black soldier fly larvae meals versus conventional meal
| Amino acids | BSF Larvae | Fishmeal | Soybean meal |
| Essential | |||
| Methionine | 2.1 | 2.7 | 1.32 |
| Cystine | 0.1 | 0.8 | 1.38 |
| Valine | 8.2 | 4.9 | 4.50 |
| Isoleucine | 5.1 | 4.2 | 4.16 |
| Leucine | 7.9 | 7.2 | 7.58 |
| Phenylalanine | 5.2 | 3.9 | 5.16 |
| Tyrosine | 6.9 | 3.1 | 3.35 |
| Histidine | 3.0 | 2.4 | 3.06 |
| Lysine | 6.6 | 7.5 | 6.18 |
| Threonine | 3.7 | 4.1 | 3.78 |
| Tryptophan | 0.5 | 1.0 | 1.36 |
| Non-essential | |||
| Serine | 3.1 | 3.9 | 5.18 |
| Arginine | 5.6 | 6.2 | 7.64 |
| Glutamic acid | 10.9 | 12.6 | 19.92 |
| Aspartic acid | 11.0 | 9.1 | 14.14 |
| Proline | 6.6 | 4.2 | 5.99 |
| Glycine | 5.7 | 6.4 | 4.52 |
| Alanine | 7.7 | 6.3 | 4.54 |
(Source: Makkar et al., 2014)
Table 3. Mineral compositions of black soldier fly larvae meal
| Mineral | Mean value |
| Calcium (g/kg) | 75.6 |
| Phosphorus (g/kg) | 9.0 |
| Potassium (g/kg) | 6.9 |
| Sodium (g/kg) | 1.3 |
| Magnesium (g/kg) | 3.9 |
| Iron (g/kg) | 1.37 |
| Manganese (mg/kg) | 246 |
| Zinc (mg/kg) | 108 |
| Copper (mg/kg) | 6 |
(Source: Newton et al., 1977)
Effects of BSF larvae on Broilers
The performance of broilers that fed BSF larvae meals was evaluated by different authors. Oluokun (2000) compared BSF larvae with SBM and FM on broiler production. The author suggested that maggot meal could replace FM to upgrade the nutritive value of SBM in the broiler diets without any adverse effect on the body weight (BW) gain, feed intake, and feed conversion ratio (FCR). The feeding of dried BSF larvae as a substitute for SBM resulted in a similar BW gain but a lower feed intake as compared to the control indicating an improved FCR (Makkar et al., 2014). Cousins (1985) reported that broilers fed a BSF-based starter diet showed daily gain and body weight at 10 days old, roughly similar to those fed the fish meal control diet (24.6 vs. 24.5 g/day, 286 vs. 285 g, respectively). These results were consistent with other studies that did not indicate any differences in daily gain or final weight during the grower phase in broiler quails fed either a control diet or BSF larvae meal diet (Cullere et al., 2016). Dabbou et al. (2018) reported that body weight and average daily gain during starter growing periods were increased due to the inclusion of BSF into the broiler chicken diets, while the average daily gain decreased linearly during the finisher stage, which may be attributed to some negative effects of dietary BSF larvae meal on gut morphology when administrated at a high level (10%).
In growing broiler quail, Cullere et al. (2016) tested three diets as control, 10% defatted BSF larvae meal (substituted 28.4% soybean oil and 16.1% SBM) and 15% defatted BSF larvae meal (substituted 100% soybean oil and 24.8% SBM). The author found that quails showed the same BW gain, feed intake FCR, and mortality rate in all dietary groups. Apparent digestibility of nutrients (DM, Organic Matter, CP, EE, and starch) was overall comparable among the three groups except for EE, whose digestibility was the highest (P<0.001) in control (92.9%) and 15% BSF meal (89.6%) groups. Feed choice trial showed that broiler quails did not express a preference toward control or 15% BSF meal diets and breast meat weight and yield did not differ among all groups. The author confirmed that BSF at an inclusion level of up to 15% as a replacement for SBM and soybean oil had no problematic effects on digestibility, productive performance as well as carcass and meat quality of quail broilers.
Effects of BSF larvae on Layers
Maurer et al. (2016)conducted a feeding trial with a partly defatted meal of dried BSF larvae in small groups of laying hens. Experimental diets contained 12 and 24% meals replacing 50 or 100% of soybean cake used in the control diet, respectively. After three weeks of the experiment, there were no significant differences between feeding groups with regard to egg production, feed intake, egg weight, and feed efficiency. There was a tendency (P=0.05) for lower albumen weight in the 24% meal group; yolk and shell weights did not differ. There were also no mortality or sign of health disorders occurred. The DM of feces increased with increasing proportions of meal in the diet, with a significant difference between 24% meal and the control groups (P=0.05). Increases of black fecal pads were observed in the 12% and 24% meal groups. Higher DM of feces and a larger proportion of dark, firm fecal pads with 24% gave reason to assume that in this diet the proportion of meal was too high. The causes of these differences are not fully understood.
Hopley (2015) tested the ability of layer hens to be reared on BSF larvae and BSF pre-pupae meal and whether this had any effect on the production parameters and egg quality and concluded that the production parameters were favorable and that the chickens on larvae meal had a lower FCR. Al-Qazzaz et al. (2016) found that the egg quality parameters were either comparable or superior to that of the control treatment and concluded that BSF larvae as a viable protein source for layer hens.In laying hens, the inclusion of 7.5% defatted BSF larvae meal into their diet from weeks 19 to 27 of age showed significantly higher body weight than other groups (Mwaniki et al., 2018). AccordingtoKawasaki et al. (2019) studies on laying hens fed a diet supplemented either with whole (non-defatted) 10% BSF larvae meal or with 10% BSF pre-pupa meal for 5 consecutive weeks did not show significant differences among treated birds and those fed the basal diet. However, Borrelli et al. (2017) reported that the complete replacement of soybean meal by BSF larvae meal in laying hens reduced their body weight (2.09 vs. 1.89 kg, respectively) after a 21-week feeding period. Van Schoor (2017) tested the effect that BSF pre-pupae meal on layer production parameters and egg quality. Results were also positive; egg quality was not affected by the inclusion of the prepupae meal and at the inclusion of 10%, production parameters were also not affected. The rate of degradation (shelf-life) of the eggs was also not affected by the inclusion of the pre-pupae meal. The author concluded that BSF pre-pupae meal may be used as an alternative protein source in layer hen diets with no significant effects on the egg quality, shelf life and production parameters. Mwaniki et al. (2018) also reported that, in laying hens, inclusion of 7.5% defatted BSF larvae meal into their diet from weeks 19 to 27 of age showed significantly higher body weight than other groups.Provision of BSF larvae also had a positive effect on the feather condition of laying hens with intact beaks (Star et al., 2020).
Generally, from the above results reported by various authors, it may be concluded that BSF larvae meal could replace FM or SBM in the broiler and laying hen diets without any adverse effect on performance.
Plans For A DIY Black Soldier Fly Farm
Now that you know why these insects are so healthy for your hens, let’s talk about how you can raise them yourself! First, you’ll need a home for your larvae, and one way to do that is to build your own.
Building your own black soldier fly larvae farm takes just a few minutes. And it doesn’t need to cost an arm and a leg. We spent less than $20 on this project and were able to upcycle scrap wood and spent shavings from our coop to complete it.
To make this project easy and accessible for chicken keepers of all levels, we used a 55-gallon plastic bin. You can buy these at any big-box store. While plastic may not be for everyone, we wanted to show how this project can be easy, accessible, and low-cost.
If plastic isn’t your thing, then you can also build bins out of wood using this same design. It’ll cost you a bit more than just a plastic bin, but it’ll last longer. If you’re not sure that raising black soldier fly larvae is for you, then stick with a plastic bin. You’ll be less financially invested in the project, and you can always upgrade to a wood bin later.
Ultimately, the goal is to cultivate a protein-rich feed for your chickens. Since the design works well with many different types of material, feel free to use wood, cement, cinder blocks, or anything else you have on hand.
For this project, you’ll need:
- Cinder blocks, or another way to raise the bin .
- A 55-gallon plastic bin and a smaller plastic bin .
- A drill with a small-circumference bit (1/4-inch is best)
- Bedding substrate (free)
- Starter feed (such as ground corn, spent fruit and vegetables, horse feed, rice bran, etc).
- Corrugated cardboard (free from post office)
- 2 pieces of wood at least 6 inches wide (wider is better) and half the length of your bin (free)
Step 1: Stack your cinder blocks and bin.
Raising the bin off the ground.
Assembling your bin is easy. First, drill a few holes into the bin for drainage, so its contents won’t become waterlogged. Next, stack your cinder blocks so the bin is raised off the ground. This is important for two reasons: First, it keeps mice and rats out of your bin. Second, it creates good circulation around your bin. You don’t want the interior getting too hot, because it’ll rot the food faster (attracting the wrong kind of insects). Additionally, if your bin gets too hot, it’ll cause your black soldier fly larvae to crawl off sooner. They’ll be smaller and less nutritious for your chickens.
If you have another way to raise your bin, such as an extra table or sawhorses, you can use that instead of cinder blocks. The idea is to just get your bin off the ground.
Step 2: Add your bedding substrate to the bin.
We used spent shavings from our chicken coop. We didn’t want the interior of our bin to get too wet. A moist, anaerobic environment rots food quickly, and attracts houseflies instead of black soldier fly larvae. Some other bedding options are newspaper, wood chips, compost, or dirt.
Step 3: Add your starter feed.
We used rice bran for this project, and just dumped it on top of the shavings. We then wet the bran a little so it made a scent to attract the female black soldier flies.
Step 4: Top it off with the cardboard.
Just place the cardboard on top of the feed. The black soldier fly ladies will know what to do!
Step 5: Add the wood planks.
Adding the rice bran to the bin
Place these into the bin, and lean them side-by-side against one side of the bin so they’re on a shallow slope (at least, as shallow as your bin allows). The idea is that these planks provide an easy way for your larvae to crawl out of the bin. You still will likely have some larvae crawl up the sides of your bin, but most will use the path of least resistance. If you notice a lot of the larvae crawling up the sides, you can catch the larvae by putting additional smaller bins below those areas as well. You can also add a lid to your bin to help contain and protect the larvae and their environment.
If you have strong winds like we do on our farm, weighing down the lid with a cinder block will prevent the lid from getting lost. This is especially important in storms, since you don’t want a lot of water in your bin. Excessive moisture can drown your grubs, cause them to crawl off too early, or attract the wrong kind of insects.
Step 6: Place your extra bin right below the wood planks.
The final bin with a smaller bin to catch future black soldier fly larvae.
Keep it as close to the ends of the planks as possible to ensure your larvae make it into the receiving bin. If you need to raise your receiving bin, just use extra cinder blocks, or something similar. Check your smaller bin daily! Adult black soldier flies only live about 7 days. In that time, they need to mate and lay eggs. Eggs take about 4 days to hatch, so you should see results quickly.
Step 7: Choose a location for your bin.
You don’t want the interior of your bin to get too hot, too moist, or too wet. If any of these conditions aren’t ideal, it can result in faster crawl-off and possible death. While the goal is to harvest the larvae to feed our chickens, you don’t want them dying too soon in your bin or crawling off before they’re large and nutritious for your birds. Choose a spot that’s in partial shade, and can keep your bin reasonably dry. Building your larvae farm in a bin lets you move it easily if it’s necessary.
Whenever we decide to set out a new bin, I look for a spot where I’ve seen larvae in the past. For example, our horses are masters at dropping their grain and mashing it into the mud. If we dig an inch or so with our boot heels and see black soldier fly larvae, we know it’s a great place to put a new bin. The flies are already attracted to that area! You can also place your bin close to your coop. Black soldier flies are attracted to the smell of chicken feed, so they’re likely already in that area.
Maintaining Your Bin and Attracting Black Soldier Flies
Now that your bin is complete, it’s on to the next step!
Your goal is to attract mature female black soldier flies and encourage them to lay eggs in your bin. These insects naturally lay eggs close to their food source. However, unlike houseflies, which lay their eggs on their food, black soldier flies lay their eggs near their food. So providing an attractive laying location, such as corrugated cardboard, is important. Any cardboard will do, although I personally would stay away from anything with a lot of ink and printing on it.
As for food, we use ground corn, rice bran, and wheat in our bins. We already have it available, and it’s less likely to attract houseflies. We also provide leftover fruit rinds, vegetables, and other kitchen waste. Experts recommend avoiding putting meat in your bin. As the meat decays, it sends off a rotting smell, which is more likely to attract houseflies. We personally don’t like the smell, so we just stick to grains, fruits, and vegetables. We’ve always had great luck with grains in particular!
Add food as needed, and keep an eye on the amount of food in your bin. If you notice it’s gone on a daily basis, add more. If there’s plenty of uneaten food in it, then hold off on adding more. While you’ll want to use leftovers from your kitchen instead of using very fresh produce, you also don’t want rotting food to create an anaerobic environment in your bin. It’ll attract maggots instead of black soldier fly larvae. It’s a balancing act, but you’ll soon get the hang of it.
How to Harvest Black Soldier Fly Larvae
As they mature, black soldier fly larvae will increase in size until they’re black and about 1 inch long. At this point, they’ll start to crawl off and out of their bin in order to move on to the next phase of their lives. Because they naturally will leave the bin, it’s very easy to harvest them. Simply wait for them to crawl off!
The planks of wood give them an easy way to leave their nest. As they crawl, they’ll eventually reach the end of the planks, and plop into the receiving bin below. You can check the bin every day for new larvae. You can then decide whether to feed them to your flock immediately or sacrifice them by freezing them.
Raising and harvesting black soldier fly larvae is relatively easy, and over time, it can provide a healthy and free source of food for your chickens.
What are the benefits of feeding insect larvae to livestock?
The increase in food demand of an ever-growing human population, as well as the need to reduce the carbon footprint of agriculture, is fueling the search for new sources of protein for animal feeding. Insect larvae seem to fulfil the requirements for a new low-cost, ecofriendly ingredient.
Main positive points of growing insect larvae for feeding livestock
- Larvae convert wastage biomass into protein and compost, creating a cycle of sustainability (Sheppard et al, 1994; Shumo et al., 2019).
- The life cycle of certain insects can be easily controlled, which is favourable for commercial production (Sogari et al., 2019).
- Mass production of insects requires less surface area than crops to produce the same amount of protein, whilst reducing the emission of greenhouse gases (Oonincx & de Boer, 2012).
- Animals species, such as fish and poultry, are naturally prepared to eat insects (Sogari et al., 2019).
- They have high levels of protein, essential amino acids, energy, and micronutrients (Makkar et al., 2014; Shumo et al., 2019)
- Their protein content is normally above 30% (Makkar et al. 2014; Spranghers et al., 2017)
- The protein is of high biological value, with high concentration in lysine, threonine, and methionine (Shumo et al., 2019).
- Larvae are rich in lauric acid, which has shown to improve gut health and have immunomodulating effects (Sogari et al., 2019
So far, house fly (Musca domestica), yellow mealworm (Tenebrio monitos), and black soldier fly (Hermetia Illucens) have been singled out as having the greatest potential to become industrialised (Shumo et al, 2019; Sogari et al., 2019; Spranghers et al. (2017). In fact, several companies around the world are already producing them at a commercial scale.
This article looks at the cycle of larvae production, focusing on black soldier fly (BSF), currently most popular species being grown to feed livestock. The focus is on the life cycle, the composition of the final product, and the factors affecting variability in composition.
The production of BSF larvae
In the production of black soldier fly larvae (BSF larvae), the flow of organic waste transformation runs parallel to the cycle of BSF (Dortmans et al, 2017). After a certain period in which waste being transformed by BSF larvae, the process renders pre-pupae larvae for animal feeds, as well as processed organic waste that can have many uses (e.g. compost, biogas production, etc.).
The transformation of organic waste
A range of organic waste can be used as substrate for growing larvae, as long as they fulfil three premises (Dortmans et al., 2017; Purschke et al., 2017):
- Water content between 70 and 80 %
- Small particle size, to facilitate the activity of the larvae
- Free from toxic waste and inorganic/non-degradable components.
Dortmans et al., (2017) classified the sources of organic waste into municipal waste (municipal waste, restaurant waste, market waste), agro-industrial waste (e.g. food processing, slaughterhouse, grain wastes), and manure/faeces. If the particle size and the moisture are beyond the expected range, they should be corrected. Contaminated organic matter should be rejected before entering the processing plant.
Spranghers et al. (2017) reared BSF larvae on chicken feed, biogas digest, vegetable waste, and restaurant waste, measuring chemical composition of pre-pupae larvae. Larvae in chicken feed grew significantly faster (12 days to the first harvest, P<0.05), with a significantly higher yield (P<0.05), and more efficient utilisation of substrate (P<0.05). Larvae in restaurant waste grew slower, probably due to the substrate’s high fat content, which is difficult for the larvae to digest (19 days to first harvest, P<0.05). Biogas digest gave the lowest larvae yield (P<0.05).
The BSF life cycle in the commercial context
Figure 1. Life cycle of black soldier fly (BSF) in a commercial setup.
The total cycle of the fly lasts, approximately, 5 to 6 weeks (Fig. 1). It starts with the oviposition of, approximately 400 to 800 eggs, after which the female dies. Four days later, the first larva stadium hatches; they are a few mm long and voracious. They continue growing for 12 to 14 days, provided they are under suitable environmental conditions and with a good organic substrate. At the end of this period, the larva enters the pupa stadium, which ends in 2 or 3 weeks-time, with the emergence of a fly (Dortmans et al., 2017).
In their single week of adult life, females look for a partner, mate, lays eggs and die. Sixty-nine percent of mating occur 2 days after eclosion, significantly affected by light intensity (Tomberlin & Sheppard, 2002). Four days after eclosion, 70% of adult females had already laid their eggs (Tomberlin & Sheppard, 2002).
By synchronizing the mating activity based on the management of light intensity, females are induced to lay their eggs at, approximately, the same time (Dortmans et al., 2017). Five days after the larvae had hatched, they are inoculated into the organic matter and the process of biotransformation begins. The temperature should be between 26 and 30 ºC, shaded and with a substrate moisture between 60 and 90%. Two to five percent of the larvae are left to grow and become adults (Dortmans et al., 2017).
They are harvested at day 12 post-inoculation, before they become prepupae, and when the nutritional properties are at their maximum point (Dortmans et al., 2017; Liu et al., 2017). The final weight is determined by the quality and amount of substrate, as well as by the environmental conditions and the level of light. In suboptimal conditions, the attained weight will be lower and the time to achieve the final stage will be longer (Dortmans et al., 2017).
After harvesting, the transformed organic matter and the larvae are processed separately. The larvae are normally dried or frozen, to be then commercialized as an animal feed ingredient. The organic product can be dried to be used as compost, or being fermented for biogas, among other uses (Dortmans et al., 2017).
Safety regarding pathogenic microorganisms and other insect species
Erickson et al. (2004) reported that BSF larvae secrete substances that repel other insects and potential disease vectors, such as common house fly (Musca domestica).
Regarding the transmission of pathogens, BSF larvae have been reported to reduce the levels of E. coli and Salmonella enterica in cow manure (Erickson et al., 2004; Shumo et al. 2019). Similarly, Liu et al. (2017) reported a reduction of the count of E. coli count in chicken manure treated with BSF larvae.
Purschke et al. (2017) found that rearing larvae in substrates contaminated with cadmium and lead reduced their growth rate and feed conversion. Larvae also accumulated cadmium and lead in their tissues (accumulation factors of 9 and 2 respectively), whilst other heavy metals remained at a lower concentration than in the substrates.
Larvae growth is not affected by pesticides or mycotoxins, and these toxins were not found in larval tissues (Purschke et al., 2017). Shumo et al. (2019), using LC-Qtof-MS analysis, also reported not finding traces of aflatoxins when examining BSF larvae grown on spent grains, kitchen waste and chicken manure.
Nutritional composition of larvae and its dynamics
Generalities on composition of BSF larvae
The composition of BSF larvae can be affected by the substrate where the larva has been reared, as well as by the larval stadia. Some components are more affected than others.
Dry matter
The dry matter of fresh larvae at harvest is quite high, between 35 and 35 % (Ewald et al., 2020; Makkar et al., 2014; Spranghers et al., 2017).
Protein
In general, BSF larvae contain high levels of crude protein (above 33 %) (Makkar et al., 2014; Spranghers et al., 2017; Shumo et al., 2019). Compared to a soybean meal (SBM) of the same protein content (44%), the amino acid profiles are quite similar (Spranghers et al., 2017). Shumo et al (2019) found that the amino acid profile of BSF larvae was superior to the FAO specifications for SBM and sunflower, with methionine levels also above the FAO standards for fishmeal. If, as SBM, BSF meal was to be defatted, the percentage of protein will increase up to 60%, with a superior amino acid composition (Spranghers et al., 2017).
Lipids
Larvae are high in lipids, and their content depend largely on the quantity and types of lipid in the substrate. Liu et al. (2017) reported a lipid content of 28% at 14 days, whilst Makkar et al. (2014) reported up to 36 % before the larvae becomes pre-pupae (Makkar et al., 2014). Although the level of unsaturated fatty acids is high in housefly meal (60-70%), it is quite low in black soldier fly (19-37%) (Makkar et al., 2014; Ramos-Bueno et al., 2016). Regarding saturated fatty acids, BSF has a high proportion of lauric acid of their own synthesis (Ewald et al., 2020), as well as low levels of cholesterol (Ramos-Bueno et al., 2016).
The high content of medium chain fatty acids (MCFAs), especially lauric (C12:0) it is of great importance in pig and poultry. Lauric acid has a probiotic action, especially against Clostridium perfringens, with lowest effect of Lactobacilli, helping to maintain in healthy microflora in the proximal small intestine (Spranghers et al., 2017). Its effect against enveloped viruses, other bacteria, and protozoa was also reported (Shumo et al., 2019).
Fibre
NDF and ADF content of BSF they are affected by NDF and ADF contents of the substrate. Shumo et al. (2019) reported values of 21%, 20% and 29 % NDF for BSF larvae reared in chicken manure, kitchen waste and spent grains, respectively. ADF values for larvae in the same substrates were 12.6%, 13% and 15 %, respectively.
Minerals
The content of Calcium is highly depending on the composition of the substrate (Spranghers et al., 2017). Phosphorus content is more consistent, varying between 0.6-1.5% DM (Makkar et al., 2014).
Other components
The presence of chitin, between 5% DM (Nafisah et al, 2019) and 8.5% DM (Spranghers et al., 2017), is of importance. Chitin has been attributed some prebiotic effects (Selenius et al., 2018). However, care should be taken of its antinutritional properties, since it has a negative effect on nutrient digestibility in animals, even at low concentrations (Nafisah et al., 2019; Spranghers et al., 2017). Fermentation of larvae with chitinolytic bacteria (Bacilllus subtilis) has resulted in reduction of chitin quality and content (Nafisah et al., 2019).
Shumo et al. (2019) reported the existence of 5 flavonoids in BSF larvae meal, two of them, apifenin and kaempherol being dependent of the concentration in the substrates.
Different factors produce modifications on the composition of larvae. Among them, developmental stage and substrate composition have an important effect. The following sections analyse their effect, focusing mainly on the effect of substrate, since the larvae are always processed at pre-pupae stage.
Regarding vitamins, Shumo et al. (2019) found pro-vitamin D, alpha-tocopherol, and gamma-tocopherol, although in lower levels than reported by
The effect of developmental stage on larvae composition
There is a change in composition as the larva develops into the different instars. Liu et al. (2017) showed that larvae rapidly increased their crude fat content between 4 and 14 days, time at which they reach the highest concentration of 28.4% DM. Between early pupae and late pupae there is a drop from 24.2% to 8.2%. The differences in fatty acid profile at different stages were attributed to the modulation of different genes involved in fat metabolism (Giannetto et al., 2020).
Studies have also performed on the variation of protein over time. Crude protein drops in the larval stage until day 12 down to 38%, thereafter increasing to 46% in early pupae, being at its highest in the adult state (57%) (Liu et al., 2017).
Since larva are harvested at just before stage, the following sections will focus mainly on the effect of different substrates in the composition of BSF at that time. Greatest attention is paid to crude protein, ether extract, and mineral fractions.
The effect of substrate on larvae composition
The effect of substrate on crude protein and amino acid profile
CP fraction is, in most cases, above 30 % DM (Table 1). Spranghers et al (2017) did not find significant correlation between CP in substrate and CP in larvae, whilst Shumo et al (2019) reported a strong correlation when using chicken manure and kitchen waste as a substrate.
Table 1. Effect of different substrates on the composition of BSF larvae1
BSF larvae consistently achieve CP values above 30 % in a wide variety of substrates. However, their efficiency is not the same for all substrates. For example, larvae reared in restaurant waste showed one of the highest protein contents, however larvae took longer in develop because of their low ability of degrading substrates with high oil content (Spranghers et al. 2017).
Regarding amino acid composition, Shumo et al. (2019) did not find any significant effect of substrate on lysine, methionine, isoleucine, leucine. Spranghers et al. (2017) reports very small variations in amino acid composition of larvae reared in different substrates. Liland et al. (2017) also reported minimal variations when increasing the levels of brown algae added to a processed wheat-based diet, from 0 to 100%.
Effect of substrate on EE fraction and fatty acid profile of BSF larvae
The EE fraction is more affected by substrate composition and larvae weight (Ewald et al. 2020; Makkar et al. 2014; Shumo et al., 2019; Spranghers et al., 2017). However, the predominance of saturated fatty acids, especially lauric (C12:0), was consistent throughout experiments and treatments (Ewald et al. 2020; Gianetto et al, 2020; Makkar et al. 2014; Shumo et al., 2019; Spranghers et al., 2017).
Ewald et al. (2020) found that there is an increase in the content on PUFAs, especially eicosapentanoic (EPA) and docosahexaenoic (DHA) omega fatty acids, when feeding fresh mussels and mussel silage. Similar results have been observed by St-Hilaire et al (2007) when feeding fish offal. Although the differences are significant respect of substrates with low or inexistent PUFAs, the ability of modifying the profile of fatty acids based on dietary changes seem to be rather limited (Ewald et al., 2020). As the larvae become heavier. As the larvae became heavier, the concentrations on EPA and DHA tended to decrease irrespectively (Ewald et al., 2020).
Effects of substrate on mineral content of BSF pre-pupae
Ash is the most affected fraction by substrate characteristics. Sprangers et al (2017) reported high correlations between the ash content of the substrate and of the larvae. The same authors found that Calcium levels were very viariable (66 g/kg for larvae grown in biodiesel digestate vs. 1g/kg for larvae fed in restaurant waste).
Shunno et al. (2019) found a lower range of concentrations when rearing larvae in chicken manure and kitchen waste (1.94 % for both) and spent grain (3.5%), although the variability of the calcium concentration in larvae reared in chicken manure was much higher than for larvae reared in kitchen waste. Makkar et al. (2014) reported higher average values of calcium (mean: 75.6 +/- 17.1 g/kg; min: 50 g/kg; max: 86.3 g/kg). Calcium concentration may further increase after fat extraction (Sprangers et al, 2017). Care should be taken with substrates high in calcium since that translates directly into high concentration of the mineral in BSF larvae meal.
Phosphorus varied between 4 and 6 g/kg, and it has been reported to be more consistent between larvae reared in different substrate (Shumo et al., 2019; Spranghers et al., 2017). However, Makkar et al (2014) reviewed higher values for phosphorus (mean: 9.0 g/kg +/- 4; Min: 6.4 g/kg; Max: 15.0 g/kg).
Effects of substrate on other components
As mentioned above, Shumo et al (2019) reported that flavonoids apifenin and kaempherol are affected by substrate composition. Shumo et al. (2019) also found that the levels of pro-vitamin D, alpha tocopherol and gamma tocopherol were not significantly affected by rearing substrate (spent grain, chicken manure, and kitchen waste).
Conclusions
The production of BSF larvae as a protein source for animal feeds is certainly a promising, lower carbon footprint option to the more traditional sources. The high protein content and quality, as well as the high content of lauric acid, are very positive traits.
One of the possible disadvantages is the high variability of some of the components. Differences in composition depend on the rearing substrate and other factors such as rearing microclimate, differences in rearing methods, harvesting times and techniques, and possibly due to genetical heterogeneity (Shumo et al., 2019). The variability can be difficult to control, especially considering the heterogeneous and inconsistent character of biological.
Currently, several groups around the world are running projects to better understand and finetune the production of BSF larvae and its inclusion in animal feeds. In upcoming articles, we will discuss the utilisation of BSF larvae in different species and production types.
Scaling up Black Soldier Fly Farming to Meet Global Demand
As the global demand for sustainable protein sources continues to rise, more and more agricultural producers are looking towards Black Soldier Fly (BSF) farming as an option. BSF farming has several advantages over traditional livestock farming. BSF larvae can be produced using organic waste, which reduces the environmental impact of waste disposal and mitigates greenhouse gas emissions. BSF larvae can also be used to produce high-quality animal feed and fertilizer, which can help to reduce the reliance on chemical fertilizers and imported feed. BSF farming offers a valuable source of sustainable protein with minimal environmental impact – but scaling it up significantly is not without its challenges. Let’s look at some of these challenges and how they can be addressed.
Despite the potential benefits of BSF farming, scaling up the production of BSF larvae presents various challenges. Below are some key challenges and potential solutions.
Challenges Of Sustainable Farming:
Regulation and policy
BSF farming is a new industry, and there are currently no global standards or regulations for BSF larvae production. As a result, there is a lack of clarity around the legality and safety of BSF larvae production, which makes it challenging for producers to enter the market. Potential solutions: Governments and regulatory bodies should develop guidelines and regulations for BSF larvae production that address safety, quality, and environmental concerns. These guidelines should be based on scientific evidence and industry best practices and should be regularly updated to reflect advances in technology and knowledge.
Infrastructure and technology
BSF larvae production requires specific infrastructure and technology, such as insect rearing facilities, feed preparation and storage, and waste management systems. These facilities and technologies can be costly and require specialized knowledge and skills. Potential solutions: Industry associations, and other stakeholders should supply support and resources to help BSF farmers build and maintain their infrastructure and technology. This support could include funding, training, and access to technical ability. At Insect Engineers, our approach to BSF farming is very practical. We have the know-how of the entire production process. This, in combination with the unique ZOEM racks, lowers your investment and improves your profit. We help farmers, not professors.
Market demand and consumer acceptance
Even if BSF farmers can scale up their operations, they may struggle to connect with buyers or market their product effectively due to limited resources or knowledge about how best to promote themselves. BSF larvae are a new and unfamiliar source of protein for many consumers, and there may be resistance to adopting them as a food source. Additionally, there may be challenges in convincing food companies to use BSF larvae as an ingredient in their products. Potential solutions: Industry associations and producers should promote the nutritional and environmental benefits of BSF larvae to consumers and food companies. They should also work with food companies to develop new products and formulations that incorporate BSF larvae.
Availability of raw materials
Another major challenge is sourcing high-quality feedstock for the BSF larvae. BSF larvae thrive on a variety of organic materials such as manure, food waste and vegetable scraps – but finding consistent sources of these materials can be difficult. Many BSF farmers rely on local waste streams, restaurant byproducts or even backyard composters – all of which tend to fluctuate in availability depending on the season or region. BSF larvae require a consistent supply of organic waste to feed on, which can be challenging to secure in large quantities. Additionally, the quality of the organic waste can impact the quality and safety of the larvae. Potential solutions: BSF farmers should develop partnerships with waste management companies, food processors, and other industries that generate organic waste to secure a consistent supply. They should also develop methods to ensure the quality and safety of organic waste, such as testing for contaminants and pathogens.
Cost and profitability
BSF farming can be expensive to set up and operate, and the profitability of the industry is uncertain. Additionally, the price of BSF larvae may need to be competitive with other protein sources to be economically viable. Potential solutions: BSF farmers should develop innovative production methods and technologies to reduce costs and increase efficiency. They should also explore different markets and niches to find. We have the know-how of the entire production process. This in combination with the unique ZOEM racks which lowers your investment and improves your profit makes us the place to go when it comes to getting started and expanding with BSF farming.
Lack of Accessible Education
Another major challenge facing BSF farmers is the lack of accessible education about this technology. Many potential farmers are unaware of the possibilities that BSF farming presents, or they do not have access to training programs that could teach them the necessary skills needed for successful production practices. To address this challenge, governments should invest more resources into creating accessible educational programs for potential BSF farmers so that they can gain the knowledge needed to start their own farms. At Insect School, we want the world to learn about Black Soldier Fly farming. By being an online news and information hub, as well as providing BSF testing facilities, Insect School is a meeting place for everyone with an interest in the Black Soldier Fly.
Limited Research & Development
BSF farming is still a new industry, and there is limited research and development for this technology. This means that farmers are relying on trial-and-error methods to maximize their yields, which can be costly and time-consuming. To overcome this challenge, governments, and organizations should invest more resources into R&D efforts to develop more efficient production practices and technologies that can help farmers increase their yields while decreasing their costs. Insect School aims to educate the world on Black Soldier Fly farming through its online news and information hub, along with BSF testing facilities, serving as a gathering point for all those interested in the subject.
Sustainable future
As you can see, there are a number of challenges that must be addressed if BSF farming is going to reach its full potential as a sustainable source of protein for the global market. By investing in R&D efforts, creating accessible educational programs, and removing regulatory hurdles, governments around the world can help make it easier for ambitious entrepreneurs to scale up their operations, so they can meet rising demands efficiently. With such initiatives in place, it’s only a matter of time until we start seeing more successful BSF farms popping up all over the world!
Edited & Shared by-LITD Team
Source-To be shared on request.
