نوع مقاله : مقاله پژوهشی
نویسندگان
1 گروه گروه علوم دامی، دانشکده علوم . مهندسی کشاورزی، دانشگاه رازی، کرمانشاه، ایران
2 گروه علوم دامی، دانشکده علوم . مهندسی کشاورزی، دانشگاه رازی، کرمانشاه، ایران
3 گروه علوم دامی، دانشکده کشاورزی، دانشگاه بوعلی سینا، همدان، ایران
چکیده
کلیدواژهها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
This research focused on evaluating black soldier fly larvae as a potential alternative protein source for animal feed by analyzing their protein fractions using the Cornell Net Carbohydrate and Protein System and assessing protein degradability with the nylon bag method. The larvae were raised on waste from a student restaurant. Upon completion of the larval growth phase, their approximate composition, fatty acid, and amino acid profiles were analyzed. Proteins were fractionated using phosphate buffer, neutral detergent, and acidic detergent solutions. Degradability was conducted with the nylon bag technique using two sheep fitted with permanent rumen fistulas. The rearing process showed that 85 grams of eggs produced 63.5 kilograms of dried larvae, and 225.76 grams of fresh larvae were generated per kilogram of feed consumed. The entire growth and hatching period lasted 15 days, with larvae reaching an average size of two centimeters. The larvae contained 41.71% crude protein and 35.01% ether extract, with high levels of essential amino acids such as methionine and lysine, and non-essential amino acids including aspartic and glutamic acids. The main fatty acids were saturated lauric and palmitic acids, along with unsaturated oleic and linoleic acids. Intermediately degradable protein was the largest fraction, while non-protein nitrogen and rapidly degradable protein made up 14.58% and 9.63% of the protein, respectively. The potential and effective degradability of crude protein at a passage rate of 0.05 were 43.97% and 31.59%, respectively. Overall, the results suggest that black soldier fly larvae possess favorable nutritional qualities and efficiently convert organic waste into valuable nutrients, making them a viable alternative protein source for ruminant feeding.
کلیدواژهها [English]
Extended Abstract
Introduction
In recent years, resource scarcity has driven up the cost of animal feed, which now makes up 60–70% of livestock production expenses. Additionally, forecasts indicate that the rapidly expanding human population will increase the demand for animal-derived foods—such as eggs, meat, and milk—by 70% by the year 2050 (Makkar, 2018). This population increase will also greatly raise the need for animal feed (Jayanegara et al., 2017). Ingredients like fishmeal, fish oil, soybean meal, and grains are increasingly used in both human and animal diets (van Huis, 2013). Soybean meal is a common protein source in animal nutrition, but concerns remain about its sustainability and environmental impact (Spiller et al., 2020). The strong demand for high-quality feed such as soybean, which are also consumed by humans, combined with population growth, has contributed to deforestation and the loss of forested land to agriculture (Hellstrand et al., 2013). Soybean meal is favored in ruminant diets because it provides essential amino acids (Campos et al., 2014). Additionally, oilseed by-products are in high demand, especially for monogastric animals (Kahraman et al., 2023). Thus, the livestock sector faces the challenge of creating innovative solutions to fulfill future societal, environmental, and economic demands. Searching for alternative feed sources is therefore critical to meet impending feed requirements. Insects have recently emerged as promising alternative protein sources for feed. Compared to traditional plant and animal-based feeds, insects offer various benefits, including low greenhouse gas and ammonia emissions, reduced risk of zoonotic disease transmission, minimal water use, and the ability to quickly convert and reduce organic waste into body mass (van Huis, 2013). Their high protein and fat content make insects suitable as protein and energy components in animal diets (Hawkey et al., 2021). Additionally, insects exhibit low feed conversion rates, require little water, and efficiently transform organic waste into body mass over a short period (van Huis, 2013). Several species, such as black soldier fly larvae (BSFL), have been evaluated in laboratory settings as potential alternative feed options for ruminants (Jayanegara et al., 2017). BSFL, due to their nutritional profile, represent a highly promising technology supporting sustainable economic development. This approach aims to reduce waste generation while lowering raw material and energy consumption. Using BSFL fosters a beneficial link between environmental sustainability and economic gains by addressing anticipated food shortages and supplying nutritious feed. These larvae can transform organic waste into valuable biomass, contributing to waste reduction and resource efficiency (Oonincx et al., 2010). On the other hand, one of the well-known methods for determining the nutritional value of feed materials is the Kernel Net Carbohydrate and Protein System, which examines materials based on nitrogenous fractions and the nature of carbohydrates (Sniffen et al. 1992). his method categorizes protein into fractions—including non-protein nitrogen, rapidly, moderately, and slowly degradable protein, as well as undegradable protein in the rumen—based on their degradation rates (Russell et al., 1992). It represents the first use of the kernel system for both quantitative and qualitative evaluation of insect protein. Because it is more precise than the crude protein method, it enables a more accurate comparison of the nutritional value of insect protein with other food sources. Conversely, the CNCPS model separates black soldier fly larva protein into degradable and undegradable fractions, which is especially important for chitin-bound proteins (such as fraction C) that conventional methods like crude protein analysis tend to overlook. Since BSLF are considered a potential alternative protein source in animal nutrition, the nylon bag technique provides a realistic evaluation of the availability of their protein within the ruminant digestive system. This approach indicates how much larval protein is degraded in the rumen—making it accessible to rumen microorganisms—and how much passes to the small intestine as undegraded protein, which can be directly absorbed by the animal. Therefore, the aim of this study was to determine the different protein fractions of BSLF reared on organic waste, based on the CNCPS, and its degradability process using the nylon bag method.
Material and Methods
This research was conducted at the Faculty of Agricultural Sciences and Engineering, Razi University. The rearing stage of black soldier fly larvae (BSFL) lasted from July 1402 to January 1402. BSF eggs (provided from Babaei Savasari BSF Breeding Farm, Sari, Iran) were reared under appropriate laboratory conditions. These eggs were hatched after three days at a temperature of 30 °C and a humidity of 70% under the recommended temperature and humidity conditions (Diener et al., 2009) with minor modifications. The very small larvae, started eating and reached their maximum size within 15 to 20 days. During the first three days of the period, the larvae were fed on wheat bran and thereafter a mixture of restaurant waste including rice and bread was prepared for them. The harvested larvae were dried in a drying oven and ground using a laboratory mill (Foss Tecator Cyclotec 1093; Foss, Hillerød, Denmark). Afterward, the chemical composition of the larvae was determined according to the proposed method (AOAC, 1990), NDF (without alpha-amylase enzyme but with sodium sulfite) and ADF according to the Van Soest et al. (1991). The amount of chitin in the larvae was measured using the proposed method of Liu et al. (2012). The fatty acid composition of BSFL was measured by gas chromatography (Agilent Technologies 6890N - USA). At the beginning, the column temperature was set to 100 °C, while the injection port temperature was maintained at 260 °C. Nitrogen was used as the carrier gas, with a flow rate of 0.1 ml/min. The detector employed was a flame ionization detector (FID), and the injector operated using the SPLIT/SPLITLESS mode. The column used was of the HP88 capillary type with a length of 100 m, an internal diameter of 0.250 mm and a thickness of 0.2 μm. The amino acid composition of BSFL was measured by high-performance liquid chromatography - reversed phase (Agilent 1100 - RP-HPLC- USA), according to the method of Rozan et al. (2000). The flow rate was 0.1 ml/min. The loop was 20 μl and the column of the device was C18 (5 μm: particle size; 150 × 4.6 mm). The fluorescence detector was with an emission wavelength of 348 nm and an excitation wavelength of 450 nm. The mobile phase consisted of a gradient blend of 0.1 M sodium acetate buffer (pH 7.2) and methanol. Protein fractions of black soldier fly larvae were analyzed following the method described by Licitra et al. (1996). The rumen degradability of BSFL was evaluated using the nylon bag technique, as outlined by Ørskov and McDonald (1979). Two two-year-old sheep with permanent rumen fistula were used for incubation of the nylon bags. Dacron bags measuring 10 x 5 cm with a pore diameter of 50 ± 10 microns (Ankom R510, Ankom Tecnology, Macedon, NY) were used. The degradability parameters were calculated from the nonlinear equation (McDonald, & Ørskov, 1979) and using Excel facilitated NEWAY software, (Fit Curve).
Result
The findings from the larval rearing period revealed that 85 grams of eggs produced 63.5 kilograms of dried larvae, and for each kilogram of feed consumed, 225.76 grams of fresh larvae were generated. The rearing and hatching process lasted 15 days, with larvae reaching an average harvestable length of two centimeters. The larvae contained 41.71% crude protein and 35.01% ether extract. They were rich in essential amino acids such as methionine and lysine, as well as non-essential amino acids like aspartic and glutamic acids. The predominant fatty acids were saturated lauric and palmitic acids, along with unsaturated oleic and linoleic acids. Intermediately degradable true protein made up the largest fraction of the protein, while non-protein nitrogen and rapidly degradable protein accounted for 14.58% and 9.63%, respectively. The potential and effective degradability of crude protein at a passage rate of 0.05 were 43.97% and 31.59%, respectively.
Conclusion
Overall, the results indicate that black soldier fly larvae possess valuable nutritional qualities and can efficiently convert organic waste into nutrients, making them a promising and suitable alternative protein source for ruminant diets.
Conceptualization, F H, D A and H A; methodology, F H and D A; software, E N and F H; validation, F H, D A; formal analysis, E N and F H; investigation, E N, F H and D A; resources, F H; data curation, E N; writing—original draft preparation, E N and F H, writing—review and editing, E N and F H; visualization, F H and D A; supervision, F H and D A; project administration, F H; funding acquisition, F H. All authors have read and agreed to the published version of the manuscript.
Data available on request from the corresponding author.
We would like to express our gratitude to the Faculty of Agricultural Sciences and Engineering at Razi University for providing the field and laboratory facilities necessary for this research. Our appreciation also extends to the Pars Hegmatan Damyar Company in Hamadan, Iran, for providing the animal feed pellets and Babaei Sosraei Black Soldier Fly Breeding Farm in Sari, Iran, for supplying the black soldier fly eggs.
The study was approved by the Ethics Committee of Razi University (Ethical code: R.RAZI.REC. 1402.043). The authors avoided data fabrication, falsification, plagiarism, and misconduct.
The author declares no conflict of interest.
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