Insect meal is a valuable source of micronutrients that are important for fish health and performance. Insects are rich in a range of vitamins, minerals, and trace elements, such as iron, calcium, and zinc. These nutrients are important for a number of physiological processes in fish, such as bone formation, immune function, and energy metabolism. For example, BSFL meals contain 5-9 % calcium.
Nutritionist & Research and Development Manager
Nutrition Technologies
A rapidly growing aquaculture industry is providing multiple commercial options for insect meal’s potential for use. The focus of these meals tends to be on the protein component but we often forget that fish in the wild use insects as a complete diet. Insect meal is a complex ingredient that can be used in ways that better match its role in natural systems, than simple a protein source.
Fish in the wild obtain the nutrients they need for growth and survival from a variety of food sources, a significant source being insects. Insects provide fish with a rich source of protein, essential for body growth and maintenance. Freshwater trout, for example, have been found to feed almost exclusively on insects ranging from mayflies to chironomid fly larvae.
Besides protein, insects also provide fish with essential nutrients such as vitamins, minerals, and fat. For example, some insects are rich in omega-3 fatty acids, which are needed for maintaining healthy cell membranes and supporting proper brain function. To specific insects, Black Soldier Fly (BSF) larvae are most often used in animal feed due to their high protein content, but they also contain other beneficial nutrients such as essential fatty acids, vitamins, and minerals, including carotenoids like astaxanthin which has potent antioxidant properties and is commonly used as a dietary supplement. Overall, insects play a vital role in wild fish species’ diets and are a crucial part of the aquatic food web.
MAKING CHITIN WORK
Insect meal is a highly digestible and palatable protein source for fish that has a similar amino acid profile to fish meal. However, in addition to its protein content, insect meal contains a range of other important nutrients that can benefit fish health and performance including chitin. Chitin is an often-misunderstood component of insect meal, while the science is still out on many aspects of it, evidence is increasingly pointing to positive elements of chitin.
Chitin is a unique nutrient that has a number of positive effects on fish health, digestive capacity and boosting immune function. One of its most important functions is as a prebiotic, which means that it promotes the growth of beneficial gut bacteria in fish (Rimoldi, et. al., 2019) These bacteria can help improve the digestive capacity of fish by breaking down complex carbohydrates and other nutrients so that they can be better absorbed by the fish. In addition, chitin has been shown to have immune-stimulating properties, meaning it can boost fish’s immune function and help them fight off pathogens and diseases. Studies have shown that the inclusion of chitin in aquaculture feeds can improve survival rates and overall fish growth (Rodolfo et. al., 2016).
MICRONUTRIENTS
Insect meal is also a valuable source of micronutrients that are important for fish health and performance. Insects are rich in a range of vitamins, minerals, and trace elements, such as iron, calcium, and zinc. These nutrients are important for a number of physiological processes in fish, such as bone formation, immune function, and energy metabolism. For example, BSFL meals contain 5-9 % calcium. Calcium is an important mineral in aquaculture diets as it is essential for various physiological processes, including bone and shell formation, muscle function, blood clotting, and nerve function.
Calcium is particularly important for species that have hard shells or skeletons, such as crustaceans and bivalves, as well as for bony fish species. Calcium deficiency in these species can result in weakened shells or bones, poor growth, and reduced survival.
Calcium is also important for the health and growth of fish and other aquatic animals that do not have hard structures. Calcium plays a role in muscle and nerve function, and deficiency can result in reduced appetite, poor growth, and increased susceptibility to disease.
Including insect meal in aquaculture feed formulations can help meet the nutritional needs of fish without the need for synthetic micronutrient supplements.
ANTIOXIDANTS & ANTIMICROBIAL PEPTIDES
Another important advantage of insect meal is its potential as a source of bioactive compounds, such as antioxidants and antimicrobial peptides (AMPs). Insects contain a number of antioxidant compounds, including vitamins E and C, carotenoids, and flavonoids, which can help protect fish from oxidative stress and inflammation. The use of insect meal in aquaculture feeds can increase the antioxidant capacity of fish, leading to better growth rates and overall health.
Insect meals have also been shown to contain a wide range of antimicrobial peptides, which are small proteins that can help protect fish from bacterial and viral infections. Black Soldier Flies have been found to have more that 50 AMPs – more than any other invertebrate. Antimicrobial peptides are naturally produced by many organisms, including insects, and have been shown to have a broad spectrum of activity against a variety of pathogens. The use of insect meal in aquaculture feeds can help boost the immune system of farmed fish and reduce the need for antibiotics and other chemical treatments that can be harmful to the environment and human health.
All this, combined with the fact that the production of insect meal for use in aquaculture feeds is a more sustainable alternative to conventional fish meal, which is often derived from wild fish populations, makes it an even more attractive ingredient in feed formulations. Insect meal can be produced from a range of sustainable sources such as food waste and agricultural by-products, reducing pressure on wild fish populations and promoting more sustainable farming practices.
About Davis Fundi Ireri
Davis is the Nutritionist & Research and Development Manager at Nutrition Technologies, an industrial-scale BSF meal manufacturer based in Malaysia. He has a background in Plant Pathology where he developed interest in agricultural entomology. Davis has been working for the last 7 years understanding the role of black soldier fly as an alternative sustainable protein source for the feed industry. He leads Bioconversion R&D at Nutrition Technologies developing the understanding of how to better formulate feed for BSFL to increase bioconversion efficiency, whilst providing the right nutrition to the larvae to optimise the meal for multiple feed applications.
