Fish Food Production Using Agro-Industrial Waste Enhanced with Spirulina sp.

Abstract

The supply of animal feed is one of the main concerns of producers in the aquaculture industry, including aspects such as the cost of fish flour and its nutritional balance. The aim of this study was the preparation of a pellet-type fish food using powdered Spirulina sp. cultivated as a protein source supplemented with agro-industrial waste, and its evaluation to comply with the necessary parameters for the elaboration of extruded pellets. Spirulina sp. was cultivated in a photobioreactor at a volume of 50 L, separated by decantation and dried. The proximal characterization was 6.79% ± 0.05 moisture, 6.93% ± 0.01 ash, 66.88% ± 0.33 protein, and 5.50% ± 0.26 fat. Subsequently, flours were prepared using cassava leaves, gliricidia leaves, and rice husks. The results for the cohesion showed that the flours obtained to comply with the necessary parameters for the elaboration of extruded food. The fish feed was prepared in pellet form using the formulation for fattening Tilapia: Spirulina sp. (20%), cassava leaf flour (50%), gliricidia leaf flour (20%) and flour of rice husk (10%). Floatation analysis showed that 60% of the pellets floated for more than 40 min, and 80% retained their shape for 4 h. The results show that the obtained product can be used as fish feed, due to the lowest disintegration, together with its great capacity for water absorption and especially, its greater flotage due to the expansion effect, are physic characteristic determinants so that the fish has more time to consume extruded diets and avoid losses.