Fly maggots can be used to reduce organic waste products that are a source of pollution and costly to manage, while simultaneously producing a cheap and sustainable source of protein.
Ms Nina Parry, a master's student in the Department of Zoology and Entomology at the University of Pretoria, is investigating the use of fly maggots to reduce organic waste and to process these maggots into a protein that can be fed to livestock and farmed fish. This innovative idea will reduce reliance on expensive and unsustainable protein products such as soybean meal and fish meal, while simultaneously reducing problematic organic waste products.
Fly maggots have been found to successfully convert and reduce waste products, such as manure, sewage, abattoir waste and kitchen or restaurant waste, into a usable source of protein. When the maggots stop feeding, they can be collected, sterilised and dried out to produce a type of protein feed that is suitable for pigs, chickens, crustaceans and carnivorous farmed fish. The leftover waste is less pungent, produces fewer CO2 and methane emissions (owing to a reduction in the presence and activity of bacteria) and can be turned into a rich form of fertiliser.
This type of nutrient recycling can be performed in industrial-size bioconversion plants, but as more information about bioconversion is made available, even smallholder farmers can produce a source of protein for their animals from waste that is naturally produced on their farms. This can alleviate the costs associated with buying protein feed and managing waste. The benefit of having an industrial-size bioconversion plant is that the waste produced in an area can be sustainably managed and a cheap and locally produced source of protein can be made available to nearby farmers.
Ms Parry is currently running experiments with several fly species that occur naturally in Gauteng to determine how well they reduce swine manure, abattoir waste and kitchen waste. Thereafter, the maggots will be processed to determine their nutritional value for use as animal feed.
According to Ms Parry, the purpose of her research is to find local fly species that are best suited to reducing different types of waste with maximum efficiency, as currently only one or two species are used to reduce all types of waste.
Ms Parry is supervised by Dr Chris Weldon, who hopes that the results of this research will provide a strong foundation for a fledgling industry that will reduce waste and provide a sustainable source of income for developing communities.