US scientists plan to reduce dairy waste using black soldier fly larvae
A new project aims to explore the environmental and economic benefits of converting dairy waste into protein for feed, with the digestion residue acting as a fertilizer.
“Black soldier fly larvae are high in protein and fat,” says Dr. Jeffrey Tomberlin, director of the Center for Environmental Sustainability through Insect Breeding and one of the study's lead authors. “In addition, they contain many key nutrients necessary for the growth and production of livestock, poultry and other animals. Such work could lead to a diversification of the foodservice industry, based more on a circular economy, by taking minimal value material such as manure and converting it into high-value products such as animal feed and fertilizer.”
He adds that interest in using insects as animal feed has met with much less resistance than interest in feeding insects to humans.
The research will be conducted in the Department of Entomology at Texas A&M College of Agricultural and Life Sciences and Mississippi State University, USA. The researchers received a three-year, $618,000 grant from the USDA's National Institute of Food and Agriculture.
The black soldier fly larvae will be placed in tubs of milk manure to test their ability to absorb waste and convert it into safe protein. During this process, the black soldier fly larvae will consume their weight in organic waste - about 1g or the weight of one raisin per day - every day for two weeks. larva Scientists explain that these seemingly small numbers add up when multiplied by millions of black soldier fly larvae.
There are facilities in Europe, Asia and North America that can process 100 metric tons of waste daily using black soldier fly larvae.
The experiments are carried out in plastic containers filled with approximately 18 pounds of manure and containing 10,000 black soldier fly eggs. The larvae hatch, consume dairy manure for two weeks, and are then collected. Then the process is repeated.
Once this procedure is complete, Heather Jordan, an assistant professor and microbiologist at Mississippi State University, will test the resulting larvae and excrement—the material left behind after the larvae digest the manure—for microbial diversity and feed safety.
Black soldier flies consume organic waste, including manure, but the recycling process leaves room for efficiency gains, the researchers say.
The study will use probiotics to improve the processing of black soldier fly dairy manure waste and remove more than 50% of the nitrogen and potassium from the waste.
Tomberlin explains, “Probiotics can manipulate a resource so that it is more easily digested by black soldier fly larvae—much like when humans consume probiotics for themselves.”
The project supports a circular economy by managing dairy waste by harnessing the natural feeding cycles of black soldier fly.
Early research suggests that probiotics can speed up the digestive process in fed animals, increase the conversion of waste into insect biomass, reduce greenhouse gas emissions and odors, and reduce concerns about pathogens that may be present in manure.
Dr. Angel Helms, another lead author of the study, notes that the team is "testing the limits" of black soldier fly production in combination with probiotics to see how effective they might be for health. livestock facilities.
“Manure management is a cost for these producers and we are testing whether it is a way to manage this waste and turn it into a productive source of feed.”
An important part of the project is determining how “safe” the collected larvae are when turned into feed ingredients, the researchers emphasize. There is limited knowledge about the diversity of pathogens in dung-consuming larvae, which may impact feed safety.
Helms suspects the manure-eating maggots are safe for livestock, but the end product requires certification.
In addition to waste disposal, black soldier fly manure recycling is also expected to provide environmental benefits, in addition to reducing dependence on traditional manure disposal methods such as waste lagoons.
“There are potential economic and environmental benefits from including black soldier fly in manure management,” states Helms. “Turning waste into a resource sounds too good to be true, but we are increasingly realizing how black soldiers can solve many problems.”
Black soldiers can eat twice their body weight each day, Tyson Foods said last month, which the company is using to create a closed-loop recycling system. The company is creating a reusable source of protein to reduce demands on land and water resources through the efficient use of animal by-products. As for other insects that can break down food waste, Tomberlin points to "some interest" in crickets and mealworms.
Photo: Texas A&M AgriLife
