Effect of fish meal replacement with Spirulina Spirulina platensis on hematite-biochemical and immune response of Caspian brown trout (Salmo trutta caspius) juveniles

In this experiment, the effect of dietary Spirulina platensis on haemato-biochemical and immunity responses of Caspian brown trout (Salmo trutta caspious) juveniles was investigated. For this purpose, diets with five S. Platensis inclusion levels (control 0%, 2 %, 4%, 6% and 8% of diet fish meal) were prepared. Six hundred juveniles with an average initial weight of 11 ± 1.0 g were assigned to 15 experimental tanks. The experiment lasted for 10 weeks. At the end of the experiment, haemato-biochemical parameters including white blood cell, red blood cell, neutrophils, lymphocytes, haematocrite, hemoglobin, glucose, albumin, total protein, triglyceride, cholesterol, as well as immunity parameters including lysozyme, C3, C4, Immunoglobulin (IgM), ACH50 and respiratory burst activity were assessed. The hematological and immunological factors were improved when fish were fed a high level of S. platensis supplement. S. platensis inclusion also increased activity of Lysozyme C3, C4, IGM and ACH50 and respiratory burst activity and reduced AST and ALT formation.These results indicate that S. platensis supplement is promising for disease prevention in S.trutta caspious juveniles, at an optimum dietary level of 6-8% in diet.