Factors affecting the decision-making process of using insect-based products in animal feed formulations

Summary

Insect meals are promising alternative feed ingredients although their application is still not commonplace. Their inclusion requires the consideration of various factors to optimise growth, animal welfare, and feed costs. The insect meal form (whole or defatted) impacts the level of inclusion, in particular in feeds where low amount of lipids is needed (e.g. poultry). From a nutritional point of view, the factors that influence the insect meal characteristics include insect species, rearing substrates and production processes. Processing (drying, defatting) can dramatically influence the nutrient digestibility and availability that requires assessment through in vivo or in vitro trials, with differences being observed in relation to the entity of the defatting process as well. The inclusion of full-fat or defatted meal may impact the final product quality (fatty acid profile). Low digestibility of chitin is also a limiting factor. Studies to increase the digestibility of insect meals using additives are ongoing. For these reasons, when different insect protein suppliers are used for feed production, chemical analyses need to be performed. In addition to the nutritional aspect, in some species (i.e. fish), a physical evaluation of the feed is necessary. In particular, the high fat content of whole larvae meal may increase the mixture viscosity and decrease the pellet stability, resulting in nutrient loss. Palatability affects feed ingestion; though insect meals seem well accepted, some palatability issues have been reported at high inclusion levels. It is however not clear if these issues are due to the level of inclusion or to some intrinsic characteristics of the meal used. Finally, the crucial factor for the future practical incorporation of insect meals in animal feeds is the availability and consistency of the supply. Without large and consistent quantities, it will be difficult for feed producers to incorporate these alternative ingredients within their production processes.