Complete replacement of fish meal in the diet of Nile tilapia (Oreochromis niloticus L.) grow-out with alternative protein sources. A review

Abstract

Tilapia culture is widely practiced in tropical and subtropical regions with an annual growth rate of 12% thanks to their high growth rate, disease resistance, and low trophic feeding levels. The increase of aquaculture production has doubled the demand for fishmeal, which has been the most preferred protein ingredient for decades. The provisions of fishmeal are not adequate to sustain the current growth rate of aquaculture industry. Studies have demonstrated possibilities of substituting fishmeal with alternative sources without affecting fish performance. This paper argues the possibility of complete replacement of fishmeal with the alternative dietary protein sources such as terrestrial animal by-products, oilseed plants, single cell proteins and plant protein rich derivatives. The nutritive values of these sources are also discussed. Blood meal and meat and bone meal are perfect fishmeal replacers in tilapia feeds thanks to their high protein and essential amino acid profiles. Soybean meal and cottonseed meal are the best plant protein sources in terms of protein and amino acid contents. Plant proteins could be supplemented with cheap minerals instead of expensive amino acids to produce superior results. The use of aquatic plants and single cell proteins in tilapia feeds should be carefully evaluated because of the varying, and sometimes conflicting results. Both biological and economic evaluations of fishmeal replacers should be studied. More long-term evaluations should be conducted in practical culture systems rather than laboratories. In conclusion, tilapia producers should consider the unconventional dietary sources because complete replacement of fishmeal in tilapia diets is scientifically possible.