Evaluating the Nutrient and Fatty Acid Profiles of Black Soldier Fly Larvae (Hermetia illucens) Raised on Various Diets in Thailand

Sarayut Pittarate^1*Chaiwat Arjin²Perumal Vivekanandhan¹Kannan Swathy¹Chun-I Chiu¹Supamit Mekchay²Patipan Hnokaew²Apinya Sartsook²Thanandon Siripan¹Korawan Sringarm^2*Patcharin Krutmuang^1*

• ¹Department of Entomology and Plant Pathology, Faculty of Agriculture, Chiang Mai University, Chiang Mai, Thailand
• ²Chiang Mai University Department of Animal and Aquatic Science, Chiang Mai, Thailand

A study was conducted to evaluate the nutritional value of Black Soldier Fly larvae (BSFL) reared on five different organic substrates: chicken feed, pig feed, soy milk residue, coconut press cake, and perilla cake. The BSFL were cultivated in metal trays measuring 23 × 15 cm for 2 to 4 weeks at a temperature of 28 ± 2°C and relative humidity of 65 ± 5%. The larvae were harvested at the prepupal stage and analyzed for their chemical composition, including dry matter (DM), crude protein (CP), crude fiber (CF), ether extract (EE), and ash (A). The results demonstrated significant variations in nutritional content based on the substrate. The CP levels in BSFL fed on chicken feed (50.55 ± 0.07%), pig feed (52.10 ± 0.14%), soy milk residue (52.15 ± 0.78%), and perilla cake (47.20 ± 0.00%) were notably high (supporting Zero Hunger, Responsible Consumption and Production)). CF content was highest in soy milk residue (7.19±1.48%) and perilla cake (5.38±0.25%). Larval growth metrics, including weight (0.22±0.01 g), length (20.38±0.36 mm), and width (5.08±0.05 mm), were also favourable compared to other substrates. In terms of fatty acid profile, the larvae contained significant amounts of myristic acid, pentadecylic acid, palmitic acid, palmitoleic acid, stearic acid, oleic acid, linoleic acid, and heneicosylic acid. Interestingly, larvae fed coconut press cake exhibited the highest levels of myristic acid (38.40 ± 0.00%), pentadecylic acid (19.47 ± 0.01%), and total saturated fatty acids (74.91 ± 0.03%). In contrast, larvae fed soy milk residue presented the highest levels of oleic acid (26.68 ± 0.06%) and linoleic acid (38.44 ± 0.07%), and showed an improved polyunsaturated fatty acid content (38.57 ± 0.03%). These findings indicate that organic byproducts in Thailand are viable substrates for producing nutrient-rich, cost-effective, and sustainable BSFL-derived feed for farm animals.