Effects of using crystalline amino acids in diets of sobaity seabream (Sparidentex hasta) on whole body proximate, amino acids composition, growth and feeding performance

Although crystalline amino acids have not been a complete replaceable feeding source but have effective roles in success of replacements of other sources of food in diets of animals; because replacement sources usually have deficiencies that restricts using of them. These restrictions could be eliminated by using crystalline amino acids. Before conducting any research in this field, it is important to know how fish response in using crystalline amino acids in diets. In this study the efficiency of using crystalline amino acids in high proportion of diets in Sobaity sebrem was evaluated by two diets in triplicate during 42 days. The FM diets were based on fish meal and the CAA diets were based on 60% of fish meal and 40% of crystalline amino acids. There were no significant differences between two treatments in feed intake, survival, biometric indices and whole body proximate; but significant differences was observed in final weight, percent of body weight increase, specific growth rate, feed conversion ratio, protein efficiency and nitrogen retention. Whole body amino acid profile of experimental fish showed that histidine and proline were two amino acids with reduced amount in CAA treatment related to the FM. The reduction of growth and feeding factors in CAA treatments related to FM treatments shows that using crystalline amino acid in high proportion in diets of sobaity sebream need more conciderations.