Livestock protein supplement of the future

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 (UP), 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.

See related photo in the right sidebar.

Researchers

• 

  Professor Chris Weldon

  Professor Christopher Weldon is an Associate Professor in Applied Entomology at the University of Pretoria (UP). He completed his undergraduate studies at the University of Newcastle in Australia, graduating with a Bachelor of Environmental Science (honours) and the Dean’s Medal. He has been pursuing research at UP since he was appointed as a lecturer in Applied Entomology in 2012.
  
  Prof Weldon says his field of research would contribute to the betterment of the world because human health and livelihoods often intersect with the activities of insects. Using a foundation in insect behaviour, ecology and physiology, his research aims to address these interactions, whether negative or beneficial, with a focus on flies but also insect pests of horticulture. Results from these studies inform sustainable management practices that can reduce reliance on pesticides but may also facilitate the beneficial use of flies.
  
  He leads a research group of postgraduate students at honours, master’s and PhD level. “We pursue projects on the traits that make fruit flies destructive and invasive pests; the behaviour and movement of fruit flies that damage our fruit for consumption and exports; the biology and management of mosquitoes and other blood-feeding flies that affect human and animal health; and the use of flies for bioconversion of organic waste to promote a sustainable, circular economy,” Prof Weldon explains.
  New research that the professor and his research group have been working on over the past 18 months has been the practical interventions that can be used by hotels to reduce mosquito abundance, the nuisance of mosquito bites and the potential spread of diseases. Such practical interventions will improve the experience of hotel guests and encourage tourism.
  
  Prof Weldon and his group have also done research on how body condition and environment affect fruit fly attraction to lures and movement in the field; the diversity, abundance, and damage caused by thrips in avocado and macadamia orchards; and how to improve surveillance of invasive pests of citrus. All this work is being done in partnership with South African horticulture industries as well as international organisations to improve the productivity and competitiveness of South African horticulture.
  His advice to school learners or undergraduates who are interested in his field is to read widely about the diversity and importance of insects. There are plenty of interesting and reputable sites featuring that kind of content, Prof Weldon says, such as Entomology Today, as well as great books on insects in southern Africa. He also suggests they join a society like the Entomological Society of Southern Africa or the Lepidopterists’ Society of Africa to learn more about insects from experts and have opportunities to work with them. “Register for an undergraduate degree programme in Entomology like UP’s BSc Entomology, he adds, “and be sure to take the right subjects in school to be admitted.”
  

  More from this Researcher

Related Photo

• 

  Ms Nina Parry