Farming insects for feeding pigs: constraints and opportunities

Farmed insects are among novel protein sources for pig feeding. In Europe, insect producers and pig breeders have to comply with rather complex rules and legal requirements, mainly related to the feed (or “substrate) fed to the insects. Annex III of Regulation (EC) 767/2009 lists a number of materials that are prohibited as substrate for insects, such as feces and “household waste”. Substrates have to comply also with EU regulations on animal proteins (Regulation 1069/2009 and the implementing 142/2011): according to these regulations, some (animal protein) sources such as manure, gut content, dead-in-shell poultry, and fallen stock are prohibited as substrate for insects. Insects are expected to be increasingly used in Europe as protein replacers in animal nutrition, and the potential species for use in pig diets are Hermetia illucens (black soldier fly), larvae of Musca domestica (common housefly), and Tenebrio molitor (yellow mealworm). Black soldiers larvae meal is a suitable ingredient in growing pigs diets, being valuable in particular for its protein, lipid and Ca content and palatability (Newton et al., 1977). The unbalanced aminoacid content of prepupae meal may be a limiting factor in diets for early weaned piglets; additional refinement, such as cuticle removal and rendering, may be necessary to make it more suitable for piglets. The common housefly (M. domestica) maggot is of particular interest because it can grow on a large range of substrates and transform wastes into a valuable biomass rich in protein and fat. Sows and piglets fed maggot meal did not show any adverse effect on performances and health, and on sensorial property of meat (Bayandina and Inkina, 1980). Positive results were observed on weaned pigs fed a soybean based diet supplemented with 10% maggot meal to replace fishmeal (Viroje and Malin, 1989). Also yellow mealworm (Tenebrio molitor) could be suitable in animal feeding due to its high content of crude protein (47-60%) and fat (31-43%), but at the moment no information is available for pigs and ruminants. Future research on insect meal is needed, focused in particular on safety hazards helping EU to assess conclusive laws on the use of insect meals in pig diets.