Nutritional value of black solder fly (Hermetia illucens Linnaeus, 1758) larvae reared on fermented milk industry waste as an ingredient of fish feed

Abstract

Black soldier fly larvae are omnivorous and have high activity of amylases, lipases and proteases in their gastrointestinal tract, so they are of interest concerning the processing of various organic industrial and agricultural wastes into biomass suitable for feeding farm animals. Black soldier fly larvae are a new protein-lipid component that seems quite promising for inclusion in the diet of fish, since its cultivation allows processing waste from various industries and agriculture. The protein obtained from black soldier fly larvae has been approved for use as a component of the feed ration for farm animals in the European Union, but the possibility of using black soldier fly larvae in aquaculture has not been fully studied and requires studying of a number of issues. In this study, the nutritional value of larvae grown using fermented milk waste was assessed by the content of fat, protein, moisture, macronutrients (K, Ca, Mg) and micronutrients (Fe, Cu, Mn, Zn, Co, Se), as well as amino acid composition. The content of fat, protein and water was estimated by the extraction/gravimetric method. The content of macro— and micronutrients was measured by inductively coupled plasma mass spectrometry (ICPMS). The amino acid composition was determined by a high performance liquid chromatography (HPLC) method adapted to this task. Chemical analysis showed that the larvae are generally of nutritional value, but additional data on fatty acid analysis and vitamin content are required. In addition, it is necessary to test the feed on fish of various species and ages in order, in particular, to evaluate the effect of the studied component on the palatability of the feed, as well as the digestibility of the chitinous cover of the insect.