What About The Utilization Of Plant-Proteins In Fish Feed?

During the last 30 years global aquaculture has expanded continuously to meet the increasing demand of fish for human consumption, which can no longer be met by fisheries captures. One consequence is an increasing demand of raw materials for aquafeeds, while the volume of fish meal (FM), the traditional major ingredients of aquafeeds, remains stable. This has forced a shift from marine resources towards plant products as ingredients for fish feed. The proportion of FM in fish feeds has been reduced by one third and is replaced by a combination of plant protein sources providing the indispensable amino acids in sufficient quantity to meet the fish needs. A wide range of plant products has been prospected to replace fishmeal. On the basis of their composition and their availability on the market, plant products most used in Europe are oilseeds (soybeans, rapeseed, sunflower) as meals or protein concentrates, protein crops (lupins, faba beans, peas), cereals (corn, wheat) or protein extracts from cereals such as gluten. Nevertheless, trials using highly substituted (little or no FM) plant-based diets highlighted physiological bottlenecks despite the diets containing all the required nutrients: decreasing feed intake, feed efficiency and growth rate and metabolic changes. Research must continue to further improve the nutritional efficiency of plant products through a reduction of their antinutritional factors and toxins contents, but also by a better adaptation of the fish to these novel feeds.