Sustainable Fish Feed Development in Ghana

Project summary

Aquaculture production in Ghana has quadrupled over the past ten years, mainly driven by the development of tilapia culture. Notwithstanding, cultured fish still constitutes less than 10% of national fish production. The sector has a huge potential for growth, especially small to medium scale operators whose productivity has remained very low. It is argued that lack of expansion is due to the high cost of formulated feeds on the Ghanaian market.

This project will build research capacity at KNUST towards state-of-the-art feed development based on locally available ingredients. The nutritional composition and quality of available potential local feed ingredients will be analysed and evaluated, and experimental feed formulations will be developed for testing in farm trials. The research group will include two PhD and three MSc students enrolled at KNUST but jointly supervised by our Danish partners. Knowledge will be transferred nationally through collaboration with farmers and at workshops including key stakeholders, and internationally through publications and conferences.

Utilizing the many potential local ingredients efficiently will not only strengthen the aquaculture sector in Ghana, but also contribute to conserve natural resources through alternative uses. Capacity building in fish feed formulation includes specific knowledge in other disciplines in research and nutritional aspects of agricultural feeds and consequently may strengthen interdisciplinary research within animal nutrition and animal feed formulation.

Outputs

Project Completion Report:

The digestibility and proximate analyses of five local ingredients (groundnut husk, groundnut cake, cottonseed cake, copra and soybean cake) were analysed;

Furthermore, the anti-nutritional factors of the ingredients ascertained and necessary pretreatment methods (fermentation, autoclaving, soaking ) were applied to the ingredients to reduce anti-nutritional factors;
The amino acid profile of the local feed ingredients determined and based on this 9 diets were formulated base on different combinations of the ingredients;

The best 2 performing diets from initial screening in tanks were mass produced and field tested under commercial conditions in ponds and cages;

Two papers have been published, three other papers are under review by peer reviewed journals for publication;

Four draft papers under internal review for publication in peer reviewed journals
. One PhD graduated in November 2017, other PhD due in November 2018;

Process underway to appoint the graduated PhD as a research fellow by university
Two Master’s students, graduated in June 2017;Two additional MSc. students have completed their data collection and writing their thesis and expected to graduate In November 2018.

Best two performing diets had under initial tank trial had lower growth performance compared to the commercial control diet due to poor floatability and other physical characteristics;

MOU signed with Cycle Farms to included insect-meal in order to improve the diets and to further refine the diets, improve floatability and make the diets more sustainable.The inclusion of the oilseed meals in the dietss resulted in higher faecal matter production between 4 and 45% compared to the Control diet. The high bulk densities of the oilseed meal diets generally reflected in better water stabilities and nutrient retention capacities. Ammonia and phosphorus excretion rates were lower in fish fed the oilseed based diets. Accumulated dissolved phosphorus in the closed systems at the end of the 24-hour sampling period was lower for the plant-based diets compared to the commercial control diets. Overall, the results from this study indicate the potential of minimising metabolic waste output using oilseed meal mixtures as replacements to fishmeal in Nile tilapia diets.