A review on replacing fish meal in aqua feeds using plant protein sources

Abstract

Until recently, fish meal was the chief protein source in the fish feed for diverse reasons collectively for its high protein content, excellent essential amino acid (EAA) profile, better nutrient digestibility, lack of anti-nutritional factors (ANFs), low price and ease in its availability. However ideal protein source of fish meal for fish feed is now at risk that threatens feed formulators to rely more on this. This example additionally makes feed formulators to look for alternative feedstuffs which can doubtlessly replace fish meal. Plant protein sources are acknowledged as the best source to replace fish meal; but they have contrasting characteristics to those of fish meal due to following attributes: Plant ingredients have ANFs, deficient in certain EAA, low nutrient digestibility, lesser nutrient bio-availability and palatability because of excessive degrees of non-soluble carbohydrates consisting of fibre and starch. These evaluation characters attributed to plant proteins have raised the controversy amongst feed nutritionists that how they can ably replace fish meal. Consistent with available evidences from research findings, it is found possible that plant proteins can replace fish meal either in part or completely when certain dietary recommended conditions are provided that are discussed in the review. Continuing further, the effects of dietary plant proteins on feeding, nutrient utilization and growth performances, protein retention, digestibility and bio-availability of nutrients, variations in biochemical compositions, flesh quality and immunity and stress responses of aquatic animals are individually discussed together with the idea of giving new avenues for future research in the current topic.