Protein Source in Fish Diets

The objective of this study was to evaluate the possibility of replacing a great part of fish meal portion in the diet of Nile tilapia fish with different level of dietary soybean meal. The results indicate that the interaction of dietary protein level and source significantly (P<0.01 or 0.05) affected of live body weight and daily body weight gain. Within each dietary protein level, increasing soybean meal level in fish diets decreased growth performance, while Feed conversion and protein efficiency ratio were insignificantly affected with the interaction between dietary protein level and source. Serum total protein, albumin, globulin, aspartate amino transferase (AST), alanine amino transaminase (ALT), glucose and total lipids concentrations were insignificantly affected with the interaction between dietary protein level and source. Within each dietary protein level, increasing soybean meal levels in tilapia fish diets slightly decreased serum total protein, albumin and total lipids concentrations. These results indicate that soybean meal can be used successfully as a replacement for fish meal protein in diets of Nile tilapia fish, the least-cost diets containing plant proteins (soybean meal) as replacements for all fish meal are suitable for tilapia fish. Reducing and fish meal protein levels and feeding soybean protein-based diet, help to reduce operating costs and increase final profits.