Black Soldier Fly (Hermetia Illucens) Meal as a Sustainable Alternative Protein Source in Aquafeeds: Effects on Growth Performance, Nutrient Utilization, and Gut Health of Pangasianodon Hypophthalmus

Abstract

The increasing demand for sustainable aquaculture production and the rising cost of conventional fishmeal have stimulated the search for alternative protein sources in fish feed. Black soldier fly (Hermetia illucens) meal has emerged as a promising insect-based ingredient due to its high nutritional value, sustainability and potential benefits for fish health. The present study evaluated the effects of graded dietary inclusion of BSF meal on growth performance, nutrient utilization, mineral digestibility, body composition, survival and intestinal morphology of Pangasianodon hypophthalmus fingerlings. A 60-day feeding trial was conducted using four experimental diets containing 0% (control), 5% (T1), 10% (T2), and 15% (T3) BSF meal as a partial replacement for fishmeal. The experiment followed a completely randomized design with three replicates per treatment. Dietary inclusion of BSF meal significantly improved fish performance, with the best results observed in fish fed the 10% BSF meal diet (T2). Fish in the T2 group achieved the highest final body weight (40.76 ± 1.62 g), weight gain (30.58 ± 1.41 g), and specific growth rate (2.56 ± 0.06% day⁻¹), along with the lowest feed conversion ratio (1.48 ± 0.03) compared with other treatments. Survival remained high across all dietary treatments, with the highest value observed in fish fed the 10% BSF meal diet (T2). Although survival differed statistically among treatments, the variation was relatively small (approximately 7 percentage points between the lowest and highest values), indicating that all diets supported good fish survival under the experimental conditions. Furthermore, T2 improved whole-body nutrient deposition, with the highest crude protein (60.4 ± 1.5%) and ash content (16.4 ± 0.5%) and the lowest lipid accumulation (10.6 ± 0.4%). Apparent digestibility coefficients were also significantly enhanced, with protein digestibility reaching 85.9 ± 1.3% and mineral digestibility reaching 74.3 ± 1.5% in the T2 group. Histological evaluation revealed improved intestinal development in T2-fed fish, showing increased villus height (502 ± 28 µm) and goblet cell density (18 ± 2 cells field⁻¹), indicating enhanced intestinal absorptive capacity and mucosal health. However, increasing BSF meal inclusion to 15% reduced performance compared with the 10% inclusion level, suggesting that excessive supplementation may negatively affect nutrient utilization. BSF meal inclusion influenced survival responses, although all dietary treatments maintained high survival rates, suggesting that the tested diets were suitable for maintaining fish health under the experimental conditions