Could insects be used to feed livestock and what would be the benefits to use insects compared to conventional animal feed?

This is the first of several consecutive articles that discuss the utilisation of insects as animal feed. Here, the legislative aspects for insects in the EU, animal feed in general, the use of insects for certain animals, and potential hazards are introduced.

Introduction

Livestock are of paramount importance for human diet and even though the proportions vary from country to country, on average around 95 % of the worldwide population eats meat (1).

In 2016, livestock that mainly consists of cows, pigs, poultry and shellfish/fish has been fed with more than one billion tons of feed. Approximately 44 % of the total animal feed was produced for poultry, followed by around 27 % for pigs, 22 % for cattle, and 4 % for animals in aquaculture (2).

Poultry, which is a generic term for mostly chickens, turkeys, quails, ducks and geese, is mainly fed with grains but also soy and fishmeal as a protein source. Pigs as omnivorous animals are also fed with grains, soy and fishmeal, as well as with oilseed meals, root crops and legumes. Cattle as herbivorous animals get grass and small amounts of grain and soy. Fish in aquaculture are mostly carnivorous, such as salmon and trout, and are commonly fed fishmeal in pellet form, but also soy, grains and legumes as cheaper protein and nutrient sources (3-6).

It is apparent that fishmeal and soy are crucial parts of animal feed. Approximately 16 to 17 million tons of wild fish (caught in the ocean) are processed into fishmeal and fish oil (including 5 million tons of fish trimmings) annually. The majority of this fishmeal and oil is used in aquacultures to rear fish for human consumption (6). However, prices for fishmeal have been risen due to high demand, especially since 2010/11, and in consequence to increased production of fish in aquacultures, farmers started to rely more on protein-rich plant-based materials for feed (6-8). The crops that are used are mainly imported from non-EU countries. In fact, only around 30 % of these crops are produced inside the EU and 70 % are imported from Brazil, Argentina and the USA. The import amounts to approximately 30 million tons annually, and soy is a major part of it. Significantly, 80% of the world’s soybean production is used as animal feed (6,7).

An alternative to fishmeal and soy could have been found in insect meal. Insects in general consist of approximately 40 to 60 % protein and up to 36 % of fat that could be fed separately as insect meal and insect oil (9). Insects are naturally eaten by cattle, pigs, poultry and fish as part of their species-appropriate diet (7). It is also not a new idea to use insects as a part of animal feed, specifically insect protein. However, in Europe during the 90s, there was a wide-ranging mad cow disease (bovine spongiform encephalopathy (BSE)) occurrence that was caused by feeding cows proteins from the remains of other cows, i.e. processed animal protein. Subsequently, almost all processed animal protein including insect protein was prohibited to be used as animal feed in the EU. An exemption was protein from fish.

Nevertheless, efforts were made to change EU legislation and finally on 1^st of July 2017, processed animal protein from insects was allowed to be used for animals in aquaculture (EU-enactment 2017/893) … however, only seven specific insect species received approval!

Before addressing the approved insect species, here are the most important arguments in favour of insects:

1) Insects meal can partly substitute for fishmeal and plant-based components in feed.  Studies in livestock showed that insect meal could substitute fishmeal in feed to a certain degree (9). Fishmeal that is used to feed poultry, pigs and fish in aquaculture is produced from wild fish caught in the oceans. Using insect meal instead could therefore possibly prevent overfishing.

Plant-based components in fish feed have disadvantages compared to fishmeal, such as less palatability, anti-nutritional components, high fibre content, non-starch polysaccharides, and a different amino acid profile. Insects, on the contrary, are much lower in fibre and anti-nutritional content, and it has been proposed that they have a better suited amino acid profile than plant based components (10,11).

Since insect meal is only allowed to feed animals in aquaculture in the EU, the following article will focus on the utilisation of insect meal in this sector.

2) Insects require less space and energy for cultivation compared to soy. Soybean cultivation in the South American countries led to a drastic change in land use, most significant to a deforestation, as well as decreased soil fertility, ruined biodiversity and the use of tremendous amounts of water (6). Even though soy will most likely remain as one of the protein source in animal feed in the near future, insect protein could partly replace it. Consequently, the impact of soy cultivation on the environment could be reduced.

Compared to soybeans, insects are very efficient in utilising energy. Since they are cold-blooded, they do not expend energy to regulate their body temperature, so energy can be used for growth and development. A study showed that the production of 1 ton of crickets, which equals to around 600 kg of protein, requires around 2.8 tons of feed and a surface of 3,100 m². For soy, estimations suggest that the production of 1 ton, which equals to around 50 kg of protein, requires around 3,200 m² of land and takes one year (9,12,13). The life cycle of the cricket species Acheta domesticus on the other hand takes only two to three months! Obviously, the cricket feed/substrate also needs to be calculated in order to estimate if rearing crickets would be feasible, ecologically and economically. But that is the great aspect of insect cultivation… insects can feed on organic waste.

3) Insects have a broad range of substrates they can thrive on, such as food waste. In Germany, around 9.6 million tons, in Italy 5.7 million tons, in the UK 5 million tons, in France 3.7 million tons, and in all 28 EU member countries combined 31.2 million tons food waste were produced in 2014. This comprises animal and vegetable waste (14). This food waste could be used to rear insects and represents a cheap and even revenue-generating substrate. After rearing, the residual substrate could be used as fertiliser for crop production or as material to remediate soil, as it is still rich and accessible in nutrients and minerals. Investigations showed that the larvae of black soldier flies, one of the insect species that is approved for animal feed production, reduced the volume of organic waste by up to 60 % in just 10 days (7).

However, EU legislation does not allow the utilisation of food waste as substrate for insects that are meant for animal feed production (according to EG 999/2001 and EG 767/2009), due to the danger of a possible accumulation of chemicals and toxins in insects. These potentially hazardous substances could eventually accumulate in animals, generate allergens or, even worse, disease and would pose harm to the animals and humans upon consumption of the livestock.

4) Insects can be cultivated all year around. Most crop plants used for animal feed production are primarily cultivated in the field and are therefore seasonally restricted in their cultivation. Insects, however, can be reared all year around indoors. They would however require stable temperatures for optimal growth and development.

5) The use of insects as animal feed could lead to more independence from the import of raw material for animal feed production and result in a more stable market for animal feed in the EU. This is especially important since the demand of Asian countries for raw material continuously increases. Additionally, the American countries that are the major producers of soybeans are not liable to the strict regulations of GMO use of EU legislation (6,7).

Sometimes, implementing changes to improve handling of environmental and ecological issues can be motivated by financial gains. In 2014, 980 million tons of animal feed were produced, and in 2016 the production increased to over 1 billion tons worldwide, which translate to a value of approximately $460 billion (approximately €390 billion) (15,2), and makes the animal feed sector a lucrative sector for innovations. These numbers represent the whole animal feed sector but the changes in EU legislation only affect the aquaculture sector. Here, the production of animals in aquaculture increases constantly. In 2012, it already reached 1.108 million tons of animals with a commercial value of almost €3.4 billion in the EU alone (7). It has to be pointed out that the EU is the no. 1 fish importer worldwide, with imports valued at US$54 billion (approximately €45.6 billion) in 2014 (16). Similarly, feed for domestic animals in aquaculture is mostly imported as well (only 5.9 million tons of feed for these animals was produced in Europe itself in 2014) (15). Production of sustainable feed and rearing of greater numbers of animals in aquaculture in the EU could decrease the need to import them to satisfy domestic consumption.