Impact of lysine supplementation on growth and development of Hermetia illucens larvae

Hermetia illucens larvae are able to convert a broad range of organic substrates into animal protein and are believed to have the potential to help solving the supply problem for animal protein in the future. Many farmed animals such as poultry or pigs need an adequate amount of essential amino acids like lysine for optimal growth and performance. In most diets for farmed animals, essential amino acids are supplemented as feed additive to avoid excessive protein intake while ensuring a sufficient supply of essential amino acids. There is no information on the requirements of lysine for the growth of H. illucens larvae. Furthermore, it remains open whether lysine may have an extra effect on growth and development in the cultivation of such larvae. The aim of the study was to evaluate, if an addition of lysine to their feed substrate will affect these parameters. Therefore, in the present study up to 3.0% crystalline lysine was added to a basic substrate and survival, growth, and development of larvae were recorded. Furthermore, larval nutritional values like crude fat, crude protein, and lysine content were analysed. The addition of lysine did not improve growth, development or nutritional values of H. illucens larvae. In contrast, the addition of lysine led to reduced larval size, survival and prepupal rates, especially when high amounts of lysine were provided. The results of this study indicate that a lysine content of 0.3% in the substrate is sufficient for optimal larval growth. Using H. illucens larvae for animal protein production could, therefore, be accomplished with less lysine compared to many other farmed animals.