Suppliers to the human food industry are under increasing scrutiny to address growing consumer interest, and demand, for sustainability – whilst limiting environmental impact. In light of this, the pet food industry too must address the same issues – and the use of insect-based proteins has been highlighted as a potential method to achieve this.
Insect proteins have the potential to support a circular economy with the human food chain, as farmed insects can be reared on waste organic matter from the human food chain. This ability to reprocess waste material utilises the resources to a greater degree and reduces its waste volume2. A symbiotic relationship between human food production and insect rearing is perceived to be a key benefit and a method to achieving a more sustainable supply chain.
Utilising ‘vertical farming’ the requirement for large quantities of quality land for insect rearing is significantly less than that required for traditional protein production and thus is not geographically restricted. Despite their ability to utilise waste material in production, energy consumption is a source of environmental impact for insect production and processing. However, despite this, the cumulative environmental impact of insect protein rearing is considered to be lower than traditional livestock rearing systems.
Currently authorisation in the UK & Europe has led to a strong uptake in the use of insects within the aquafeed industry, and an increased interest for use in the feed for farmed species3. Within the pet food industry under regulation No 2017/893 only seven species of insect are approved for use4. All species have a high feed conversion rate allowing for a high turnover rate from hatching to processing, thus ensuring that a consistent supply chain can be maintained. Nutritionally these species vary in amino acid profile (Table 15) and digestibility (Table 25), and highlight the diverse potential for use as protein sources.
CP, Crude Protein; BSFI and BSFp, black soldier fly larvae and pupae; HC, house cricket; YMW, yellow mealworm; LMW, lesser mealworm; PMM, poultry meat meal; FM, fish meal; SBM, soyabean meal; tlAA, total indispensable amino acids.
†Calculated as described in Kerr et al. (2013) using minimal requirements for growth of kittens and puppies6 as reference values.
The use of BSFL oil is also an area of interest in pet food production. As a by-product to the processing of BSFL for the fish feed industry this resource is readily available, and additional processing again aids a circular economy. Refining of BSFL oil can reduce the level of saturated FAs present, aid palatability and improve production characteristics such as viscosity9. The presence of high levels of saturated fat could however be of benefit in the inclusion of pet feed. Lauric acid has been previously studied for antimicrobial effects on Gram positive bacteria. Spranghers et al (2018)10 studied the impact of BSFL inclusion on the diet of weaning piglets. On weaning, nutritional and environmental stressors place gut microbiota under increased physical stress, which increases the risk of the growth of Gram negative bacteria. As hypothesised inclusion of BSFL within the study diets was shown to have a desired antimicrobial effect, however the high levels of lauric acid potentially impacted on palatability and resulted in a reduced feed intake at high inclusion. Further research for optimal inclusion levels is required, but the potential for inclusion in puppy or kitten diets to utilise this added value could be of interest.
BSFI and BSFp, black soldier fly larvae and pupae; HC, house cricket; YMW, yellow mealworm; LMW, lesser mealworm; PMM, poultry meat meal; FM, fish meal; SBM, soyabean meal.
To Bee or not to Bee?
Despite the nutritional benefits, and clear sustainability advantages insect-based feeds can provide, consumer acceptance for use in pet food is varied. PROteinsect found that 70% of surveyed people deemed it acceptable to incorporate insect protein into the feed of farmed animal species17. However, 88% of survey participants highlighted that availability of information surrounding the use of insects was lacking.
As the culture of ‘pet parents’ grows, insect use in companion animals will require transparency and readily available information on aspects such as supply chain, nutritional profiles and current research findings in order to improve consumer acceptability3. In particular feed safety is often raised as an area of concern by consumers. Preliminary studies by Vandeweyer et al (2017)18 analysed batches from multiple rearing systems and across two insect species. Results found no presence of Salmonella, Listeria monocytogenes or Escherichia coli. The absence of such pathogens is a key factor for ingredient approval under EU regulations.
To date no negative impacts of feeding insect-based diets have been documented19. However, data from controlled studies is often based on small sample sizes, over short-term feeding durations. Further feeding trial data on palatability, acceptability and impact on health are required – for both short- and long-term feeding. Such data is vital to provide a further insight into the optimal inclusion and use of insects in pet food formulation. Ensuring optimal nutrition with evidence-based claims will aid owner acceptability of this novel ingredient.
1. Swanson, K. S., Carter, R. A., Yount, T. P., Aretz, J. & Buff, P. R. Nutritional Sustainability of Pet Foods. Adv. Nutr. 4, 141–150 (2013).
2. Acuff, H. L., Dainton, A. N., Dhakal, J., Kiprotich, S. & Aldrich, G. Sustainability and Pet Food: Is There a Role for Veterinarians? Vet. Clin. North Am. – Small Anim. Pract. 51, 563–581 (2021).
3. Insect Biomass Task & Finnish Group. The Insect Biomass Industry for Animal Feed – the Case for UK-based and Global Business. http://fera.co.uk/media/wysiwyg/Final_Insect_Biomass_TF_Paper_Mar19.pdf (2019).
4. The European Union. Commision Regulation (EU) 2017/893 amending Annexes I and IV to Regulation (EC) No 999/2001 of the European Parliament and of the Council and Annexes X, XIV and XV to Commission Regulation (EU) No 142/2011 as Regards the Provisions on Processed Animal Pro. Official Journal of the European Union 92–116 (Commission Regulation, 2017).
5. Bosch, G., Zhang, S., Oonincx, D. G. A. B. & Hendriks, W. H. Protein Quality of Insects as Potential Ingredients for Dog and Cat Foods. J. Nutr. Sci. 3, 482982 (2014).
6. National Research Council Committee on Dog and Cat Nutrition. Nutrient requirements of Dogs and Cats. (National Academic Press, 2006).
7. Ewald, N. et al. Fatty Acid Composition of Black Soldier Fly Larvae (Hermetia illucens) – Possibilities and Limitations for Modification Through Diet. Waste Manag. 102, 40–47 (2020).
8. Spranghers, T. et al. Nutritional Composition of Black Soldier Fly (Hermetia illucens) Pepupae Reared on Different Organic Waste Substrates. J. Sci. Food Agric. 97, 2594–2600 (2017).
9. Mai, H. C. et al. Purification Process, Physicochemical Properties, and Fatty Acid Composition of Black Soldier Fly (Hermetia illucens Linnaeus) Larvae Oil. JAOCS, J. Am. Oil Chem. Soc. 96, 1303–1311 (2019).
10. Spranghers, T. et al. Gut Antimicrobial Effects and Nutritional Value of Black Soldier Fly (Hermetia illucens L.) Prepupae for Weaned Piglets. Anim. Feed Sci. Technol. 235, 33–42 (2018).
11. Belforti, M. et al. Tenebrio Molitor Meal in Rainbow Trout (Oncorhynchus mykiss) Diets: Effects on Animal Performance, Nutrient Digestibility and Chemical Composition of Fillets. Ital. J. Anim. Sci. 14, 670–676 (2015).
12. Kilburn, L. R., Carlson, A. T., Lewis, E. & Serao, M. C. R. Cricket (Gryllodes sigillatus) Meal Fed to Healthy Adult Dogs Does Not Affect General Health and Minimally Impacts Apparent Total Tract Digestibility. J. Anim. Sci. 98, 1–8 (2020).
13. Finke, M. D. Complete Nutrient Composition of Commercially Raised Invertebrates Used as Food for Insectivores. Zoo Biol. 21, 269–285 (2002).
14. Lei, X. J., Kim, T. H., Park, J. H. & Kim, I. H. Evaluation of Supplementation of Defatted Black Soldier Fly (Hermetia illucens) Larvae Meal in Beagle Dogs. Ann. Anim. Sci. 19, 767–777 (2019).
15. Henry, M. A. et al. Review on the Use of Insects in the Diet of Farmed Fish: Past and Future. Anim. Feed Sci. Technol. 203, 1–22 (2015).
16. Islam, M. M. & Yang, C. J. Efficacy of mealworm and super mealworm larvae probiotics as an alternative to antibiotics challenged orally with Salmonella and E. coli infection in broiler chicks. Poult. Sci. 96, 27–34 (2017).
17. PROteINSECT. Insect Protein – Feed for the Future Addressing the Need for Feeds of the Future Today. White Paper: Insects as a Sustainable Source of Protein vol. 2016 h:/proteinsect-whitepaper-2016.pdf (2016).
18. Vandeweyer, D., Crauwels, S., Lievens, B. & Van Campenhout, L. Microbial Counts of Mealworm Larvae (Tenebrio molitor) and Crickets (Acheta domesticus and Gryllodes sigillatus) From Different Rearing Companies and Different Production Batches. Int. J. Food Microbiol. 242, 13–18 (2017).
19. Beynen, A. Insect-Based Pet Food. Creat. Companion 40–41, (2018).