Over one billion tons of animal feed are produced annually in the world, generating an estimated annual turnover of more than US $400 billion (https://ifif.org/global-feed/statistics/). Fishmeal and fish oil are found in many animal feeds because they contribute the nutrients necessary to complement other, often plant based, ingredients. Both are made predominantly from wild caught small fishes, such as anchovies and herring. Unfortunately, this is not an environmentally and economically sustainable approach. Most of these fisheries are currently either harvested at capacity, or overharvested. As a result, landings tend to decline, while prices tend to increase. Furthermore, these fish species are suitable for human consumption and constitute an important part of many cuisines around the world. Feeding them to animals extends the food chain and results in unnecessary losses of energy along the way.
Black soldier flies provide a good alternative to fish for formulating animal feeds. Since they are raised in captivity on what otherwise would have been waste products, their harvest has no detrimental ecological effects typical for commercial fishing. Furthermore, many species of farmed animals, such as poultry, pigs, and many fish species, had insects as a natural part of their diets back when they still lived in the wild. Therefore, their digestive systems are already set up for processing black soldier fly larvae.
In some cases, animals can be fed live black soldier fly larvae. In other cases, the larvae may undergo minimum processing, such as being dried, canned, frozen, or ground into a paste. Most commonly, however, harvested larvae are processed into partially defatted and protein-rich insectmeal and into insect oil. Similar to fishmeal and fish oil, these are then mixed with other ingredients to make formulated feeds.
Substituting fish for black soldier fly is not without challenges. Domestic animals cannot be simply switched onto a diet of black soldier fly larvae. Just as humans, they require a diverse and balanced menu and cannot subsist on a single food item, no matter how naturally delicious that item is. This is why making formulated feeds is important. Furthermore, the chemical composition of insectmeal and insect oil are different from that of fishmeal and fish oil. As a result, they cannot directly replace each other one-to-one. However, both nutrient composition of various feed components, as well as nutritional requirements of domestic animals are fairly well known. Therefore, designing new mixes is usually not very difficult.