Potential use of a queen bee larvae meal (Apis mellifera ligustica Spin.) in animal nutrition: a nutritional and chemical-toxicological evaluation

The aim of the research was to propose the larvae of honeybee queens, discarded from royal jelly production as possible dietary supplement in animal nutrition. To this purpose, queen bee larvae were collected along three months, from 15 beehives at the royal jelly collection. The weighed larvae were freeze-dried, and the yield of meal production was calculated. Then, chemical characteristics, chitin content, amino acid, fatty acids and mineral profile (including toxic elements) were determined in triplicate on pooled samples. Queen bee larvae meal is rich in chitin, protein, essential amino acids, and in some essential minerals such as phosphorous and magnesium; it is also relatively poor in fat, and with negligible levels of toxic elements such as Cd, Pb, As and Hg. However, its fatty acid profile showed a very low amount of polyunsaturated fatty acids, and the meal was poor of Ca and other trace elements when compared to the most common insect meals used in animal nutrition. Queen bee larvae have a standard nutrition based on royal jelly and this could represent a great advantage to use in animal production. However, the collection of queen bee larvae does not allow to give high quantities of final product due both the low amount of larvae collected (an average 58.9 g/hive/month) and the relatively low yield in meal (an average 23.12%) recorded. Thus, the queen bee larvae meal cannot be considered as an alternative protein source in animal production but could represent a potential feed supplement to include at low doses to exploit the possible activities of gut microbiota modulator due to the high levels of chitin.