Insect meals are promising ingredients in aquafeeds, offering potential to meet the rising demand for protein driven by the rapid expansion of the aquaculture sector. Black soldier fly (BSF; Hermetia illucens) larvae meal is particularly promising due to its high nutritional value and environmentally sustainable production. This study investigated the effects of BSF meal on the growth performance, feed utilization, and intestinal health in Nile tilapia (Oreochromis niloticus) juveniles.
A 5-week feeding trial was conducted with Nile tilapia juveniles (initial body weight: 7.28 ± 0.09 g) in tanks (13 L each) in a RAS. Three isonitrogenous and isolipidic diets were formulated based on the known nutritional requirement of tilapia to contain 0 % (Control: BSF0), 20 % (BSF20), and 40 % (BSF40) of defatted BSF meal (Table 1). The fish were divided into 3 groups of 16 fish in triplicate tanks and were fed the diets at 5 % biomass per day. After the feeding trial, the final body weight (FBW), weight gain (WG), specific growth rate (SGR), protein efficiency ratio (PER) and feed conversion ratio (FCR) were improved significantly with increasing BSF meal inclusion levels in the diet (Table 2). The survival rate (SR) of the fish were not affected by BSF meal compared with the control. Histology analysis revealed that intestinal mucosal fold length (MFL), muscularis thickness (MT), and goblet cell density (GCD) were significantly elevated by BSF meal compared with the control (Data not shown). In addition, intraepithelial lymphocytes (IELs) and the enterocyte microvilli length (MVL) were elevated significantly in BSF40 fed fish compared with the control.
Discussion/conclusion
Results of this study aligns with most previous research on Nile tilapia. Unlike earlier studies that primarily replaced fishmeal with BSF meal, this study maintained fishmeal at lower-than-typical levels and incorporated BSF meal at the expense primarily of soybean meal and corn gluten meal. Hence, the results show that BSF meal can be used as an alternative to these in Nile tilapia fed low fishmeal diets.