A team of researchers have performed what they believe to be the world’s first environmental impact analysis of insect meal as a feed additive. The results show that in a life cycle eco-impact assessment insect meal as an animal feed raw material did not perform as well as fishmeal or soybean meal. While the results could prove damaging to the insect meal industry, which has often claimed to be a more sustainable feed source, others claim that the research highlights the potential for growth in this new animal feed raw material sector.
The research team was formed from a collaboration of scientists from the National Research Institute of Science and Technology for Environment and Agriculture (IRSTEA) and the Joint Research Unit Soil, Agro- and Hydro-systems (UMR SAS), both based in France. They analysed, “Data obtained over a period of 9 months from Ynsect, a French producer of mealworms located near Besançon, whose meal and oil are currently used for research and pet food. The production system is at the scale of a pilot mill and is designed to produce up to 17 t of fresh larvae per year.
The Goal
The team’s goal was to compare the environmental impact of mealworm larvae meal with the impact of soybean meal from Brazil and fish meal from Peru. The analysis was in two parts, the impact at the mealworm farm, and the impact at the feed mill.
As they reported to the business and the environment journal Cleaner Production, the study calculated the environmental impact of, “production, storage and transport of feed ingredients to the feed mill; the farm building; and the equipment, electricity, water consumption and wastewater treatment associated with the rearing and processing units.”
The impact of running the company and the workforce were not included in the study, and significantly, the mealworm manure (produced at a rate of 3.85 kg per kg of mealworm meal) that was subsequently used as fertilizer on nearby farms, was also excluded.
The Practice
The environmental impact assessment at the mill covered, “An animal feed manufacturer provides flour and meal feed ingredients to the insect farm, and an industrial grinding mill provides wheat bran. All ingredients originate in France and are assumed to be produced within 300 km of the feed mill.”
To assess environmental impact at the mealworm farm, the researchers calculated larval feed intake (“because it contributes the most to environmental impacts in most livestock production systems and is also strongly linked to farming practices”), and electricity consumption (“which tends to be the second largest contributor to environmental impacts in enclosed animal breeding and varies according to the climate and farming practices”).
To calculate environmental impact at the feed mill, the researchers analyzed meal yield of the extraction process (“which depends greatly on the dry matter content of fresh larvae, which itself depends directly on diet and rearing conditions, especially climate (i.e. humidity, temperature, air renewal) in the building and housing trays”), and electricity consumption (“because it contributes the most to environmental impacts of most industrial extraction processes, such as those for soybean meal and fishmeal”).
The Results
Surprisingly, larvae meal generally had a higher environmental impact than other protein sources (soybean or fish meal).
As the team reported, “Feeding mealworm meal to poultry or fish would decrease the economic and environmental efficiency of these production systems. Thus, using mealworm meal in animal feed does not currently decrease environmental impacts of livestock. The results seem to indicate that for several impacts, larvae meal protein can compete with plant protein but less so with protein from fish meal. The energy required to produce larvae meal protein is a key issue that can be improved with changes in rearing and extraction techniques.”
Although the team did add that, “These results must be considered with caution, because the chemical composition (e.g. EAA profile, fatty acids, vitamins, minerals) and digestibility of larvae, soybean and fish meals differ; therefore, they cannot directly replace each other in livestock rations.”
The Recommendations
Interestingly, the researchers outlined several ways that insect meal feed could become a more environmentally-friendly product. While some of these recommendations are out of the control of insect meal producers, others seem imminent as the insect meal industry grows, and research continues.
- Improved insect biorefinery design. Greater consideration could be given to energy consumption and eco-friendly practices in designing next-generation insect larvae farms. For example, mealworms could be fed low-value agricultural byproducts such as palm tree pulp flour, dried distillers grain or spent grain from makgeolli.
- Upscaling may help lessen environmental impact, as efficiencies of mass production improve performance. For example, mass production insect biorefineries could be located closer to the large amounts of plant waste and byproducts needed as insect feed.
- Improved legislation to enable insect protein for human consumption.
- Better understanding of how insect protein is absorbed by target animals. Will pigs react better to one type of worm fed one type of biomass, better than ruminants fed another type of worm fed a different feed?
- In the future, use of soybean and fishmeal will become increasingly expensive and have a larger and larger environmental impact. As the authors note, “Soybean [meal] is associated with deforestation and impacts from pesticide use and transportation. Fishmeal and fish oils are the main food source for carnivorous farmed fish, but harvesting fish for feed depletes fish stocks and contributes to higher prices.”
In general, the researchers note that the insect meal industry is very much in its infancy. As such there are numerous ways that feed manufacturers could improve efficiency, utilise economies of scale, and increase end-product effectiveness.
As the team reports, “…little is known about how to optimize several critical steps in a mass-rearing system, such as insect diet (i.e. limiting amino acids), reproduction (i.e. how to synchronize egg laying of mealworm beetles), and farming practices (i.e. how to maintain the best temperature and humidity in mass-rearing systems).”
Clearly there is still much to be done to make insect meal the best environmental and economic option. But given that soybean meal and fishmeal feed manufacturers have a ‘head start’ on research, and have fine-tuned their products over the decades, then it is understandable that insect meal may perform badly in these early days.
While research like this may show the inefficiencies and poor environmental record of the insect meal feed industry, it also highlights the great opportunities to improve and make a success of this exciting new feed raw material.
Photo credit: ScienceDirect, AGfunder, imgarcade, InternationalScienceTimes
