Soybean meal, appropriate substitute for fish meal in diet fish: A review

Due to the high cost of fish meal in fish diet, reducing the levels of it can result in decreasing the cost of diet. Among alternative protein sources for fish meal, soybean meal appears to be the most appropriate one because of its supply, price and amino acid profile. On the other hand, plant proteins like soybean meal contain many antinutritional factors (like protease inhibitors, non-digestible carbohydrates, phytase, lectin and etc). These antinutritional factors may affect the digestion or absorption of nutrients. Also, some researchers have represented the main limitations in the use of soybean meal are attributed to the low level of methionine, the presence of anti-nutritional factor and complicated carbohydrates. For eliminating some of these effects soy protein concentrate is used, which typically contains 65-70% crude protein. Studies on various fish species have revealed that the levels of fish meal replacement with soybean meal and growth rate are inversely related. The discrepancy among researchers regarding the use of soybean meal as a protein source for fish may be related to the quality and processing of soybean meal, variation in diet formulation, and differences in fish species , size and culture systems. So it can conclude that replacing of soybean meal as a protein source in the meal of fish is different and previously should be studied and considered separately.