Animal feed 2.0: A bug diet for chicks, fish
Sometimes the quest to replace traditional protein sources involves doing things that don’t sound very appetizing. Such as: growing fly larvae by the millions, fattening them up with food waste and then turning them into animal feed — otherwise known as fly farming.
Unpleasant as it sounds, farming black soldier flies has the potential to tackle some of the world’s most pressing agricultural problems: food waste, dwindling supplies of animal feed, which is based predominantly on wild-caught fish, and the carbon footprint involved in catching those fish in the Southern hemisphere and shipping them primarily to the wealthier north. At least 15 million metric tons, more than 10 percent of the global catch of wild fish, are used for feed.
A company with goals for fly farming on a global scale is AgriProtein in South Africa. Founder Jason Drew was in San Francisco recently to talk about plans to open 20 fly farms in North America, possibly including one in Stockton as early as this year. Fly food is not a leap when you think of fish and chickens’ natural diets, says Drew, who has been working on the idea for about 10 years.
“I remembered as a boy in England, the only way to catch fish was with a fly or maggots on the end of a hook,” he says. Plus, he points out, what do chickens like to do in the pasture? Munch on grubs.
“In our tests, nine out of 10 chickens prefer larvae to fish meal,” says Drew, aware of the need to lace any maggot-oriented pitch with humor. The feed also works on other single stomach animals like pigs, though not for cattle.
Locally, the Perennial restaurant in San Francisco processes food waste with soldier flies, which are used in its aquaculture farms. There are other companies at work to produce algae-based replacements of fish-based animal feed, such as TerraVia in South San Francisco.
Drew explained how one of his AgriProtein facilities works: Food waste comes in, and then workers add fly eggs, which then grow as they eat through the waste, turning into nice, big, nutritious maggots.
Starting with 120 tons of food waste, the daily goal for each facility, the output is 22 tons of maggots that are turned into animal feed, which they call MagMeal; 44 tons of compost; and the rest is water that can be re-absorbed into the environment.
AgriProtein builds a fly farm on the outskirts of a city or in an agricultural area, where it can process either post-consumer food waste — rotten vegetables from a grocery store or restaurant table scraps — or agricultural waste. For cities like San Francisco with zero-waste goals, the alternative is to turn all food waste into compost, but then you miss out on the protein byproduct the flies provide.
Drew says Mag Meal’s biggest potential is for farmed baby fish and day-old chicks because it has the potential to replace the subtherapeutic antibiotics they usually require. Maggots, after all, have antimicrobial qualities, something that has been known at least since Genghis Khan brought them into battle to treat soldiers’ wounds, as Drew likes to point out.
“It’s been tested on nature for 100 million years,” he says. “Who are we to improve on that?”