Hello everyone, my name is Hannah Bailey and today I will be talking about insect meal and its potential use as an alternative protein source in swine diets.

At the end of this presentation I would like you to recognize the need for alternative protein sources within the animal agriculture industry, to understand how substrates fed to black soldier fly larvae can have an influence on their nutrient composition, and learn how both full-fat and defatted black soldier fly meal can be used in swine diets.

Here is a brief outline of what I will be talking about. First I will go over why there is a need for alternative protein sources in the animal agriculture industry. Then, I will talk about black soldier flies' lifecycle, their amino acid composition in comparison to other protein sources, and their potential use in swine diets. Lastly, I will leave you with current limitations of the industry, a conclusion, and areas of future research.

Factors giving rise to the need for alternative protein sources:

The FAO has estimated that there will be 9 billion people in the world by 2050. This is a growth of over a third from 2009 to 2050. With this increase in population there will need to be a 70% increase in overall food production from 2007 to 2050 and a 40% increase in animal protein production.

To support increased food production, global crop cultivation will need to grow 90%. This growth will have to come from higher yields and increased cropping intensity because expansion of arable land will be less than 5%. There will be a 12% increase in Sub-Saharan Africa and Latin America, but an 8% decrease in developed countries. 

So why use insect meal as an alternative protein source?

First off, there are regulations in the EU (European Union) preventing the use of insect meal in livestock diets. Insect meal is classified as a Category 3 processed animal protein material (PAP), meaning it is fit but not intended for the human food chain. PAPs are also prohibited in food-producing animal diets due to the Bovine Spongiform Encephalopathy regulation (BSE). This past year, the EU approved the use of insect meal in aqua feed and in 2020 they will reevaluate the ban for swine and poultry feed. The EU only allows 7 insects to be reared for the production of insect meal. These include two fly species (including the black soldier fly), two mealworm species, and three cricket species.

The US regulations are not as clear. The FDA lists allowed percentages of insect fragments in some agriculture products but these limits are not applicable when insects are purposefully added. Since insects do not fall into any food category, companies can file for GRAS (generally recognized as safe) approval. In 2016, the FDA approved the use of dried black soldier fly larvae in salmon diets for Enterra, which is a company based in Canada.

Research is being funded by many government agencies. PROteINSECT is a European co-financed project coordinated by the Food and Environmental Research Agency in the UK, and it's partnered with companies from Africa and China. This project aims to evaluate sustainable methodologies and economic viability of insect meal. DESIRABLE is a French academic and industry funded project that focuses on the use of insect meal to replace fish meal and soybean meal. GREEiNSECT is funded by Danish International Development Agency, and it focuses on the mass production of insects as novel and supplementary sources of protein in Kenya.

There is an increased interest in raising black soldier flies due to their ability to convert organic waste into protein-rich feeds at a high rate.

So, looking at their lifecycle: The adult life span is 5-8 days. They rely on fat stores from the larvae stage as they are unable to feed due to a non-functional mouth piece.  The females can lay 500 or more eggs, which are laid close to the substrate that the larvae will live off of. These eggs will hatch in about 4 days. The larvae will live in the substrate until they are matured. Maturation can take 2-4 months depending on food availability. The larvae will pass through 6 instars during this  maturation. After the sixth instar a prepupa will develop. It will rid itself of its digestive tract and use its non-functional mouth piece to migrate to a dry space for the pupa stage. The pupa  stage can last anywhere from 14 days to 5 months. Producers often harvest black soldier flies at the prepupa stage to take advantage of their migratory habits for self-harvesting.

Black soldier fly larvae are known to volatize organic waste very efficiently, so Newton and colleagues, in 2005, developed a system to rear and harvest black soldier fly larvae under swine housing units. A manure belt is installed under the swine housing unit which will separate the urine from the feces. The urine will go into a urine nutrient recovery pit, while the feces will move to the black soldier fly rearing pit that can contain 90,000 to 100,000 mixed aged larvae. The residue manure, which is anything left over by the black soldier fly larvae, will go into further treatment or storage. Once the larvae have reached maturation and are in the prepupa stage, they will climb up a 35 degree ramp into collection containers for further processing or storage. The black soldier fly will then either be dried and sold as full-fat black soldier fly insect meal, or they'll be rendered and sold as defatted black soldier fly insect meal. Rendering will cause amino acid concentration to increase about 40%, producing a higher protein meal. Rendering will also produce an oil byproduct that can go into the biofuel industry.

Tschirner and Simon conducted a study in 2015 to look at how the composition of a substrate fed to black soldier fly larvae impacts the composition of said black soldier fly larvae. The young larvae were raised on a commercial turkey feed for 8 days to ensure optimum development after hatching. A mixture of middlings were used for the control group, DDGS were used for the protein group, and dried sugar beet pulp was used for the fiber group. These substrates were chosen because they are common byproducts and can be considered as main components for a commercial black soldier fly larvae production plant.

The black soldier fly larvae in this study were collected in the fifth or sixth instar. The crude protein level in the black soldier fly larvae fed the fiber substrate was significantly higher than the black soldier fly larvae fed the protein substrate. However, both these protein levels are comparable to that of soybean meal. Crude ash was significantly higher in the black soldier fly larvae on the fiber substrate compared to the protein and control substrates. Ether extract was significantly higher in the black soldier fly larvae on the protein substrates. However, if the black soldier fly larvae were to be rendered and defatted, their protein composition would increase and result in a meal that is more closely related to fish meal.

Tschirner and Simon took a closer look at the amino acid composition of the black soldier fly larvae on the control substrate of mixed middlings. They compared this to the amino acid composition of a black soldier fly larvae published in the literature along with fish meal and soybean meal. Arginine and phenylalanine of the control black soldier fly larvae group were 80% lower than that of the black soldier fly larvae that is in the literature. Lysine and methionine were about 22% and 43% lower than fish meal. But, compared to soybean meal, the lysine content was similar and the methionine was 10% higher in black soldier fly larvae. Threonine in black soldier fly larvae is comparable to both fish meal and soybean meal. Overall, the black soldier fly larvae fed on a mixture of middlings had a desirable amino acid composition and could be substituted for fish meal or soybean meal.

Newton and colleagues in 1977 conducted the first and one of the only studies looking at replacing soybean meal with black soldier fly larvae in diets fed to young pigs. Diets were formulated to have a 20% protein level with soybean meal or black soldier fly larvae being the single protein source, meaning no supplemental amino acids were added. The larvae used in the black soldier fly larvae based diet had 42.1% crude protein. Diets were also formulated to have 13% ether extract. The larvae used had a high percent of ether extract due to its ability to store large quantities of fat as an energy reserve for the pupal and adult stages.

The nitrogen intake was greater for pigs fed the soybean meal diet. However, the nitrogen extracted in the urine was greater in pigs fed the black soldier fly larvae diet. This ultimately led to a lower nitrogen balance in pigs fed the black soldier fly diet. Newton and colleagues looked at the amino acid levels in the two diets and found that methionine and cysteine were limited in both diets, and that threonine and tryptophan were limited in only the black soldier fly larvae diet.

Newton and colleagues also looked at the palatability of the black soldier fly larvae diet and found no significant differences in average daily feed intake when compared to the soybean meal diet with added fat. The soybean meal diet without added fat was just used as a control. Overall, black soldier fly larvae can be used with synthetic amino acids to replace soybean meal in young pig diets. It can also be utilized at lower levels along with soybean meal to avoid possible problems arising from the black soldier fly larvae high ash content and a few of the limiting amino acids. 

Spranghers and colleagues conducted a study in 2018 where they fed full-fat and defatted black soldier fly larvae meal to young pigs. The table shows the differences in composition between the full-fat and defatted, or rendered, black soldier fly larvae meal. The percent of crude protein increases around 20% resulting in levels closer to that of fish meal. Ether extract decreases, as it was removed during the rendering process. And consequently both ash and calcium are increased.

Spranghers and colleagues fed four diets to young pigs and looked at performance characteristics. There was a control diet with soybean meal and no black soldier fly larvae meal; a diet with full-fat black soldier fly meal included at 4% partially replacing soybean meal; a diet with full-fat black soldier fly larvae meal included at 8% replacing all of the soybean meal; and a defatted black soldier fly larvae meal replacing all the soybean meal. There were no significant differences seen between any of these treatments.

Apparent ileal digestibility for dry matter, ether extract, and protein were looked at for each of these diets. Digestibility did not largely differ between treatments, resulting in an overall conclusion that considerable amounts of full-fat or defatted black soldier fly larvae meal can be included in young pig diets.

Research suggests that black soldier fly larvae meal can partially or completely replace both fish meal and soybean meal in livestock diets. If insect meal replaced 10% of fish meal in the European Union aqua market, the demand for insect meal would increase 80,000 metric tons. If it replaced 1% of soy or fish meal in the Netherlands poultry market, insect meal demand would increase 70,000 metric tons. And if it replaced 1% of soy or fish meal in the Netherlands swine market, insect meal demand would be 800 tonnes. Note that these are relatively small markets, meaning the potential for insect meal could be even greater once the US and the EU regulations are revised.

However, there are some limitations holding back insect meal. The current price of soybean meal is significantly lower than black soldier fly meal, soybean meal being at 375 US$ per metric ton and black soldier fly larvae meal being between 600-1300 US$ per metric ton. The need for optimizing insect rearing systems will eventually decrease this cost, and also upscaling and automation will help. The government regulations are also causing issues with the sale of black soldier fly meal in livestock diets. Consumer attitudes in the developed countries are also causing a limitation for the sale of insect meal in livestock diets.

Amino acid composition of black soldier fly larvae meal is very similar to that of soybean meal. This means that black soldier fly larvae meal can partially or completely replace soybean meal in livestock diets. Full fat and defatted black soldier fly larvae meal can be added to young pig diets without any adverse effects on performance. Also, black soldier fly meal may replace fish meal or soybean meal in diets fed to aqua, poultry, and young pigs.

Some future research that still needs to be considered is the use of different substrates, and the insect nutrient requirements on these different substrates. The amino acid digestibility of insects fed to swine also needs to be considered. Scaling up production will help decrease the costs of insect meal and make it more competitive on the market. Fair and competitive market pricing needs to be considered in order for it to completely or partially replace soybean meal and fish meal.

Thank you for listening, and if you would like to know more about this topic, or know more about nutrition in general, I would encourage you to visit our website at nutrition.ansci.illinois.edu.