BY DONALD T. CHIDOORI, COMMUNICATIONS SPECIALIST
Intensive fish farming relies on the use of properly balanced feeds which in turn, are based on a variety of high-quality ingredients such as soyameal, fishmeal and fish oil. However, following challenges in securing soya meal in 2019, farmers had difficulties in accessing feed as prices soared beyond their reach. To help reduce the cost and accessibility of fi sh feed for farmers in Zimbabwe, the Zimbabwe Livelihoods and Food Security Program (LFSP) with funding from Department for International Development (DFID) and collaborating with Chinhoyi University of Technology (CUT) is leading an initiative to promote the use of Black Soldier Fly (BSF).
“This initiative will help reduce the cost of feeding fish by utilizing the much cheaper BSF protein in diets for fish. Feed constitute up to 80% of the production costs of poultry and fish. Any cuts in production costs will thus result in improved margins for farmers,” says Ali Said, FAO Chief Technical Advisor for the LFSP.
The Black soldier fly – Hermetiaillucens is a common and widespread fl y. Of note is that the BSF is not a vector of diseases or a pest like the regular housefly. Instead, the BSF produces a quality protein, which is similar to fishmeal, as it contains a lot of essential amino acids.
In addition, BSF larvae has a high oil content of 30%, which can substitute fish oil in fish diets. The conversion efficiency of black soldier fl y typically ranges between 12 and 20% depending on the type of organic waste. This translates to roughly 6kgs of fresh pig manure giving 1kg of fresh larvae. “Such yields, combined with the need to find cheap and reliable protein feed for fish present a big opportunity for the BSF,” says Willie Masimbiti a Livestock Specialist, with FAO, Zimbabwe.
“So far we have worked with the Chinhoyi University of Technology (CUT) and consultants from Kenya to train 45 public and program extension workers in BSF production. We are also in the process of establishing demo sites across all LFSP districts,” added Ali.
To date 120 sites have been identified and lure bins have been set up to attract initial BSF colonies from the wild. 28 lure sites have already been colonized and these will be used to distribute starter cultures to the other sites across clusters.
By December 2020, a total of 200-demonstration sites would have been established in the three geographic clusters where the program is being implemented by Welthungerhilfe, Practical Action and World Vision; directly benefitting an estimated 2000 households.
What to Feed the BSF Larvae
The BSF grows well on organic waste such as fresh manure (cattle, pig, goat and poultry), fruit and vegetable waste. Most of these organic materials are normally available at farm level, which makes it easy and cheap for farmers to produce black soldier larvae.
Performance of Fish Fed on BSF Larvae
For fish, the larvae may be fed live directly to the fish or incorporated into commercial diets. Recent trials with salmon fish have shown that BSF can replace fishmeal 100% with no adverse effects on performance in terms of growth rates and final mature weights. This however is still a new area and research on optimal inclusion levels for diff erent fi sh species is still on-going
BSF production does not require specialized infrastructure. The initial production costs are the construction of dark and lovers cages for the adult breeding flies and the construction of feeding bins for the larvae. An estimated USD62 is needed for the initial setup. Once the simple production infrastructure is in place the only costs will be labour and the cost of delivering the waste substrate to the farm. Images provided by The Zimbabwe Livelihoods and Food Security Program