Insect larvae (Hermetia illucens) as an alternative feed source for laying hens

Sammanfattning: The European egg industry is dependent on imported soy which contributes to climate change, partly because of deforestation and transport. Therefore, alternative feed sources are needed. The levels of soy used in poultry feed in Sweden are lower than the general levels in Europe. Also, the soy used in poultry feed in Sweden is certified to ensure sustainable production. Insects like H. illucens can be produced locally using local byproducts or food waste and have a similar content of crude protein and composition of amino acids as soybean, which could make them a suitable alternative. This review compiles available information about limiting factors of replacing soybean with H. illucens in the diet of laying hens and its effects on feed intake, feed conversion rate, egg production and egg quality. Levels of inclusion are also evaluated. Main findings are that H. illucens contain a high amount of crude protein and adequate amounts of most nutrients for laying hens. Egg quality appears to be improved when the inclusion level of H. illucens is 17% but effects on other parameters are less clear and sometimes contradictory. Inclusion level of 12% has shown no adverse effects on feed intake, feed conversion rate, egg production and egg weight. Furthermore, a prebiotic effect of H. illucens in the diet of laying hens has been suggested where chitin may play a key role. In conclusion, an inclusion of 17% of H. illucens gives inconsistent results regarding production parameters but 12% inclusion entails no deleterious effects on production. To determine the optimal level of inclusion further research is required.