From traditional to industrial use of insects as feed: a review

Insects are part of the natural diet of fish and poultry species and to a lesser extent of pigs, dogs and cats. In traditional farming, poultry gather their food in a free roaming manner, and insects are part of the diet. Similarly, a large fraction of the diet of freshwater fish consists of aquatic insects. These features are exploited by farmers all over the world, as feed costs are high. For example, farmers lure termites to baskets filled with organic matter, and the insects are then fed to chickens. They also employ light sources above fishponds to attract insects for their fish. More sophisticated methods are, for example, attracting naturally occurring houseflies to containers filled with organic waste, e.g. manure. The captured maggots or pupae are then fed to poultry. We discuss the following insect groups as feeds for poultry, pigs, fish, dogs and cats: bees, caterpillars, cockroaches, flies, grasshoppers and termites. Feed for poultry can also consist of insect pests, which are then controlled at the same time, for example ducks to control rice pests. Moreover, leftovers from the silk industry can be used to feed chickens, pigs and fish. Insects are also commonly used as bait for fishing. The interest in a more industrial production of insects such as the black soldier fly and housefly as animal feed started in the 1970s. In the last 15 years, large-scale rearing of insects for animal feed has taken off, with the industry receiving more than 1.5 billion dollars in investment. The market is expanding, the legislation is becoming more conducive, while academic interest is increasing exponentially. The environmental, nutritional and functional benefits of insects as feed are becoming more and more recognized. Insects are poised to play an increasingly prominent role in shaping the future of animal feed production.