Amino acid requirements of neonate larvae of the black soldier fly, Hermetia illucens

Summary

Amino acid (AA) requirements in black soldier fly larvae (BSFL) during the neonatal phase remain poorly investigated. A semi-artificial low-protein diet (NC, negative control, 14% protein) was compared to a poultry feed (PC, positive control, 18% protein) and a diet with 20 single AA added to NC to obtain a diet with 18% protein content simulating the AA profile of PC (RC, reference control). Additionally, 12 diets were formulated in which the six AAs Lys, Met, Thr, Arg, Ile and Trp were individually varied by either omitting or doubling respective contents, resulting in a reduction or excess of 31 to 46% relative to PC and RC (-AA and +AA treatments). In triplicate replication 10 000 neonates were reared for 10-14 days. Growth was most compromised in NC and -Lys. While -Met and -Trp growth was similar to PC, responses for -Arg, -Ile and -Thr were intermediate between PC and NC. Surplus levels of Met, Thr, Trp, and Ile did not, but of Lys and Arg improved performance compared with PC. Consequently, the fattening phase started 1–5 days earlier. Concluding, (i) Lys was first limiting in NC, (ii) Arg, Ile and Thr co-limited growth and (iii) Met and Trp did not limit growth. Striking responses of the indicator ‘age to target weight’ highlight the sensitivity of BSF neonates to differential AA provisions, with practical relevance for scaling up BSFL productions. Consequently, dietary AA supply considerably impacts economy of neonate production as a shortened production cycle would allow more production cycles per year.