Aquaculture is crucial for global food and nutrition security but it relies on raw materials that are often acutely finite or unsustainably produced such as fishmeal and soybean meal. Global fishmeal production is stagnant, while soybean meal faces food-feed competition and its use must be limited in the diets of carnivorous fishes. Insect meals, especially from black soldier fly (BSF), hold promise as an alternative due to their high protein content and minimal environmental needs, providing potential for sustainable production. This study investigated the effects of BSF meal on growth, feed utilization, and intestinal health of mirror carp (Cyprinus carpio) juveniles.
An 8-week feeding trial was conducted with C. carpio (initial weight: 6.44 ± 0.05 g) in tanks (13 L, each) in a RAS. Three experimental diets were prepared based on the known nutritional requirement of carp to contain 0 % (Control: BSF0), 20 % (BSF20), and 40 % (BSF40) defatted BSF larvae meal (Table 1). The fish were divided into 3 groups of 20 juvenile fish in triplicate tanks and were fed the diets at 4 % biomass. After the trial, compared to the control group, the final body weight, weight gain (WG), specific growth rate, protein efficiency ratio and feed conversion ratio (FCR) were improved with increasing BSF meal inclusion levels in the diet (Fig. 1). Histological analysis revealed significantly elevated intestinal mucosal fold length in BSF-fed fish compared to control fed fish (Fig. 2). However, the lamina propria width, muscularis thickness, goblet cell density, and intraepithelial lymphocytes were not affected by the diets. Therefore, BSF meal can serve as a suitable protein source in the diets of C. carpio, promoting growth performance and feed utilization. However, scaling up insect meal production is essential for reducing costs and enhancing its viability as a raw material.