Influence of protein supplement in the diets of larvae <i>Hermetia illucens</i> on protein accumulation and bio- mass growth

Abstract

With the enormous increase in food and agricultural residues, there is a need to find new ways to dispose of the waste. One of the promising technologies is the bioconversion of organic waste by Hermetia illucens larvae or Black Soldier fly (BSF) larvae. BSF larvae can transform low-value raw materials into protein-and fat-rich entomological biomass, which can be used as raw material to produce feed for livestock, poultry, and aquaculture. To improve this technology and increase bioconversion efficiency, research into the selection of optimal feed rations for BSF larvae is necessary. This study aims to analyze the effect of high-protein experimental diets fortified with fish meal (FM) on protein and fat accumulation in larvae, entomological biomass growth, and larvae’s growth rate in achieving the pre-pupal stage. As part of the experiment, dieting wheat bran with different fish meal contents (5 %, 15 %, 30 %) was modelled, and a diet consisting of wheat bran was used as the control diet (CD). Larvae were also reared on a standard diet, chicken feed (CF), for comparison. The results indicate that larvae reared on CF observed the maximum entomological biomass growth rate. The highest protein content in larvae was found when insects were raised on high-protein diets with fish meal at 15 % and 30 % and was 53.31 ± 0.67 % and 54.33 ± 1.02 % in dry matter, respectively. The highest fat content was found on the control diet fed without protein supplement – CD (41.57 ± 1.75 %). The larval development rate on the modelled diets was assessed on the last day of the experiment by the number of pre-pupae. The highest number of pre-pupae was obtained on FM 15 % and FM 30 % and was 13.38 ± 3.42 % and 11.52 ± 3.87 %, respectively. The highest feed conversion BER (Bioconversion Efficiency Rate) was 33.29 ± 3.54 % at CF. Proteins and carbohydrates are the most significant nutrients when modelling feed rations.