This project aims to show the economic case for producing Black Soldier Fly Larvae on fish farms for use as feed, thereby improving the sustainability of salmonid aquaculture and enhancing fish welfare.
This work investigated the impacts of live Black soldier fly (‘BSF’ Hermetia illucens) larvae supplementation in the diet of farmed trout in Britain. We’ve confirmed farmer trout quicky acclimate to supplementation of feed with live larvae, and observed no evidence of uneaten larvae in both commercial and academic trials. Both sites reported the fish having a slightly enhanced appetite for the BSF larvae over the regular pellets.
The results from the academic partner Sparsholt demonstrated BSF fish were healthier, had a consistently better appetite and therefore the potential to eat more food. Appetite is an important welfare indicator. Similar findings can be extrapolated from the commercial trial, albeit the findings have been inconclusive due to challenging water conditions due to severe drought in the summer. Additionally, a taste test performed by Mere Trout showed a small preference for the BSF fed fish over the control group.
Overall, our work confirmed it is not only possible, but desirable, for trout to be partially fed in live BSF larvae. This paves a way for lower carbon footprint diets in farmed trout in Britain, therefore helping reduce reliance on unsustainable inputs such as fish and soybean meals.
Mere Trout Ltd