For many years, animal feed manufacturers and feed additive suppliers have been discussing the pros and cons of using insects as a raw material for animal feed. Much of the research conducted focused on the safety aspect of feeding insect protein to farm animals, with the practice generally being agreed as safe.
This has meant that recently, many of the legal barriers preventing the use of insects in animal feed are to be dropped. As AllAboutFeed reported in December 2016, “The EU Member States representatives endorsed a European Commission proposal from the EU Standing Committee on Plants, Animals, Food and Feed (SCoPAFF). The text is expected to be formally adopted during the spring 2017, which means that insect proteins should be effectively authorised for use in fish feed as from 1st July 2017.”
This was a move that was widely celebrated. For example, Jason Drew, co-founder of South African based AgriProtein (the world’s biggest fly-farmer) stating that. “[The] move by EU regulators [to allow insects to be used in aqua feed] brings insect protein into the mainstream of ingredients permitted in animal feed. This is a big step forward for the environment and for world food security. Trawling the oceans to produce fishmeal is one of the most destructive activities on the planet. Replacing fish protein with insect protein in animal diets allows us to dedicate our oceans to production for human consumption alone.”
Beyond European legislators, last July Enterra claimed a “significant step forward” when it gained Canadian government approval for using, “Dried Black Soldier Fly Larvae as a feed ingredient for poultry broilers.”
Meanwhile, the use of insect meal looks set to expand, because as recently as March 17th, FeedNavigator.com was reporting how, “The International Platform for Insects for Food and Feed (IPIFF) is now aiming to step up its lobbying efforts to ensure EU regulatory overhaul to allow insect meal to be used in other non-ruminant species such as pigs and poultry.”
The method is being seen as a saviour for modern farming. A method that will lessen the use of fishmeal as a feedstock, and so aid the recovery of global fish numbers, as well as providing a sustainable source of phosphates and amino acids.
However, it does pose a new problem. What to feed the insects on?
Cattle Manure for Insect Feed
The answer, according to research conducted by a team from Cornell, may be to use cattle dung as a feedstock. In the study, they found that cattle faeces could provide enough energy and nutrients to feed housefly larvae on an industrial scale.
Reporting on the research, the online journal Phys.org stated how, “The researchers – for the first time – analyzed how efficiently housefly larvae recycled nutrients from dairy cattle manure, and they measured the nutritional value of the resulting larva meal as a feed ingredient.”
The report continued by outlining some of the many benefits of using cow dung as a feed for insect larvae, explaining how, “Their analysis showed that fly larvae lessened the overall mass of the manure and reduced total nitrogen by nearly 25% and phosphorus by more than 6%. Reducing levels of these nutrients in manure makes a more suitable compost. Otherwise, untreated manure used as fertilizer leads to runoff of excess nitrogen and phosphorus into streams and rivers, which causes eutrophication in lakes and oceans, contaminates groundwater and can spread disease.”
The study also found that the insect meal was a good source of calcium and phosphorus, and had levels of protein and amino acids that were comparable with fish meal, as well as a 20% fat content that was high in monounsaturated fats.
The research team published their results in full in the journal PLOS One, where they conclude that, “Our results demonstrated that dairy cattle manure presents a balanced substrate for larval growth, and the spent manure showed reductions in concentration of total nitrogen (24.9%) and phosphorus (6.2%) with an overall reduction in mass. Larva yield at an optimum density was approximately 2% of manure weight. Nutritional analysis of M. domestica larva meal showed values comparable to most high protein feed ingredients. Larva meal was 60% protein with a well-balanced amino acid profile, and 20% fat with 57% monounsaturated fatty acids, and 39% saturated fatty acids. Larva meal lacked any significant amount of omega-3 fatty acids. Evaluation of micronutrients in larva meal suggested that it is a good source of calcium and phosphorus (0.5% and 1.1% respectively). The nutritional value of larva meal closely matches that of fishmeal, making it a potentially attractive alternative for use as a protein-rich feed ingredient for livestock and aquaculture operations.”
Explaining the results, Vimal Selvaraj, an associate professor of integrative physiology in the Department of Animal Science at Cornell and a senior author of the research, said, “We concluded from the study that the overall composition of larva meal with respect to all nutrients, including amino acids and minerals, is comparable to fishmeal and would be a good alternative for use as a protein-rich feed ingredient for livestock.”
The current trend to expand the use of insects as a raw material in animal feed is a healthy trend. With an increasingly hungry planet, and depleting fish stocks, any practical alternative that will give animal feed manufacturers more options is welcome; especially those that can make a more affordable, healthier and sustainable product.
However, some feed experts have questioned the practicality of fly larvae for industrial processing. The fact that fly larvae yields are typically only 2% of manure weight, has led many feed manufacturers to question the profitability of the feedstock. But this ignores the fact that, for example, the U.S. livestock industry currently generates 335 million tons of dry manure per year. Such a large amount of dung would make a lot of insect meal.
For now the researchers hope that their study can remove some of the concerns that fly larvae is an impractical and unprofitable feedstock for animal feed. As Selvaraj says, “In farming-dense regions there is enough manure available to have a substantial impact on larva meal production. This paper is a first step toward realizing this potential.”