Maggots To The Rescue?


The humble maggot (larva of a fly) is being nurtured as an alternative protein source for livestock and fish farming feed, and could eventually reduce global reliance on the multi-billion dollar fishmeal industry.

A South African-based entrepreneur and his environmentalist brother have established a small pilot plant near Stellenbosch in the Western Cape, that will be up scaled next year into a trial plant converting millions of the grubs into one and half tons of a rich protein powder per day to supplement commercial livestock and fish diets.

According to its website, Agriprotein Technologies is pioneering the industrialization of maggot farming as part of a “new industry called nutrient recycling: using organic waste to create protein” the core of which is a “protein-based feed [derived from maggots] for monogastric [single stomach] animals…. varying neither in protein content nor amino acid composition.”

The fishmeal industry predominantly catches small pelagic fish, which are processed into a highly nutritious powder that is one of the mainstays of commercial animal and fish food production, although opinion remains divided as to the impact the industry has on ocean resources.

Fishmeal as a protein powder is currently unrivalled. While vegetable proteins such as soya and sunflower are also used as supplements, they are less efficient.

The UK’s Sea Fish Industry Authority (SFIA), established in 1981 to assist in supporting a sustainable fisheries industry, said in its October 2011 factsheet that global production in the world’s 300 fishmeal plants “has been around 5 million tonnes of fishmeal over the last four years… This is all produced from about 20 million tonnes of whole fish and trimmings.” Trimmings comprise about a quarter of the content (and about one million tons of fish oil is also produced from the total).

The ratio of fishmeal in farm animal diet varies from 1-5 percent, while “a typical farmed salmon diet contains 20-30 percent fishmeal and 15-20 percent fish oil,” the factsheet says.

Agriprotein’s managing director David Drew told IRIN that with world population expected to increase from seven to nine billion by 2050, a growing middle class demanding a greater meat and fish diet, and increasing competition for land for food and biofuel, it was necessary to find a source of protein for fish farming and livestock rearing which did not rely on marine resources.

The maggot farming idea was driven by David’s brother and partner Jason Drew, author of The Protein Crunch, Civilization on the Brink.

Flies feed on slaughterhouse waste

David Drew says the common household fly lays up to 750 eggs in its life (up to one month) and one kilogram of eggs will turn into 380kg of protein within three days of hatching.

The maggots are harvested just before becoming pupae, then heated and processed to emerge with the consistency of a fine “talcum powder”, he said, with one ton of the product requiring about five tons of maggots, or “about 200 million of the little critters”.

As a businessman, David Drew said, cost considerations were vital. Disposing of slaughterhouse waste is costly so if the flies could feed on it that was an efficient form of disposal, and added value to the waste. Magmeal – the brand name of the maggot feed – could be processed close to where the need was, so transportation costs were all but discounted.

Factory size would depend on available waste, so “in some places like the US mid-west [where livestock production is intensive] it would be big,” David Drew said, adding that a large factory could produce about 20 tons of maggot protein powder a day.

Elsje Pieterse of the University of Stellenbosch’s animal science department, and engaged in research for Agriprotein Technologies, told IRIN: “Magmeal works exceptionally well and is an easily convertible protein for livestock and fish” and does not contain toxins associated with vegetable proteins.

She said production of protein for animal and fish feed from other sources (such as hospital and dairy waste) using the life cycle of the fly, was also being researched.

Protein sources for livestock and fish farming are being investigated by other companies, especially in Asia, and include microbial and algal species, as well as silkworm pupae.

Stable cost base

David Drew said cost would determine the viability of proteins derived from maggots, but fishmeal production costs would always rise, while protein from maggots would have greater price stability, as there were fewer price variants such as diesel costs.

To produce one kilogram of farmed fish requires about 2kg of wild fish used in fishmeal. “With capture fisheries production stagnating, major increases in fish food production [for human consumption] are forecast to come from aquaculture. Taking into account the population forecast, an additional 27 million tonnes of production will be needed to maintain the present level of per capita consumption in 2030,” said the 2010 Food and Agriculture Organization (FAO) State of the World Fisheries and Aquaculture (SOFIA), published in January 2011.

About 65 percent of the world’s fishmeal production is used for aquaculture, according to industry estimates.

Global per capita fish consumption has reached a record high and SOFIA estimates annual consumption at “almost 17kg per person on average,” accounting for at least 15 percent of the annual protein intake of more than three billion people.

SFIA spokesperson Karen Green told IRIN: “Fishmeal has gone up dramatically in the past year. It’s supply and demand. There are less fish around [especially from the Peru market] causing a higher price – so people have looked to other alternatives [such as soya] – but in aquaculture you cannot really replace fishmeal.”

Peru accounts for about 60 percent of world’s fishmeal production. Green said Peruvian fishmeal, sourced mainly from Anchovy and Jack Mackerel, sold in 2009 for US$820 a ton; in 2010 it sold for $1,600 ton – although soya prices remained stable over the same period.

The Fishmeal Information Network notes on its website that the types of fish used for fishmeal had rapid reproduction and stock recovery abilities, and that “stocks of Peruvian anchoveta, for example, are severely depleted by a warm current of water (El Niño) every seven to ten years in the eastern Pacific Ocean. However, natural stock replenishment usually takes just 12-18 months, supported by careful fisheries management and surveillance schemes.”

Apart from Peru, other top producers of fishmeal are Chile, Thailand, USA, Japan and Denmark.

Ecosystem threat

“Globally the demand for and use of fishmeal has increased rapidly, especially in some of the emerging aquaculture countries in Asia. China is the single largest user of fishmeal,” the SFIA factsheet said.

The peak level of catch for fishmeal production was 30 million tons in 1994. Britain consumes more fish for fishmeal than it does for human consumption, according to the FAO. However, SFIA said, “fishmeal production also provides a major outlet to recycle trimmings from the food fish [for human consumption] processing sector, which might otherwise be dumped at extra cost to the environment and the consumer.”

Jacqueline Alder, a senior researcher involved in a nine-year study, Forage Fish: From Ecosystems to Markets, published in 2008 by the University of British Columbia in Canada on fishmeal production, reportedly said: “Society should demand that we stop wasting these fish on farmed fish, pigs and poultry. Although feeds derived from soya and other land-based crops are available and are used, fishmeal and fish oil have skyrocketed in popularity because forage fish are easy to catch in large numbers and, hence, relatively inexpensive.”


IRIN is an independent, non-profit media organization. IRIN delivers unique, authoritative and independent reporting from the frontlines of crises to inspire and mobilise a more effective humanitarian response.

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