Aquaculture and the utilisation of plant wastes in fish feeds

Abstract

The growing aquaculture industry uses fish diets containing fishmeal as the main protein source. As part of the global drive to replace fishmeal with a more reliable, sustainable and cost-effective protein source, CSIR Biosciences investigated the use of plant-derived proteins in fish feeds. Cereal waste products such as brewers' spent grain and sunflower press cake were evaluated, as well as soya oilcake, a biodiesel by-product. During feeding trials with these plant-based waste products, marine and freshwater fish performed well in terms of consumption, growth, feed conversion ratio and mortality rate. It was therefore concluded that soya oilcake or high protein brewers' spent grain has the potential to partially replace fishmeal in fish diets.