Hamed Nekoubin *,Mohammad Sudagar
A growth trial experiment was conducted for 90 days to evaluate between two aquatic plants (Lemna sp. and Azolla filiculoides), a xerophilous plant (Alfalfa) and two formulated diets with different protein levels (25 and 35%) on growth performance, survival rate, biochemical parameters and body composition of grass carp (Ctenopharyngodon idella). Initial weight of grass carp was 15.41 ± 0.51 g in five treatments with three replicates in each treatment experiments under field and fiberglass condition. The grass carp in experimental treatments were fed by Fed plant origin diet with 20 percent of body weight and formulated diet with 5 percent of body weight (3 times a day). Growth performance, survival rate, Feed Conversion Ratio (FCR), Specific Growth Rate (SGR), Mean Corpuscular Volume (MCV), Mean Corpuscular Hemoglobin (MCH), hematocirit, hemoglobin and total protein were found higher for alfalfa diet group compared to all other experimental diets (P<0.05). These results suggest that alfalfa diet appears to be more adequate for a better growth of this fish, followed by Lemna sp. and had significant difference from other treatments (P<0.05). The lowest growth performance, survival rate and biochemical parameters measurements was observed in pellet diet containing 25 percent protein that it had significant difference to other treatments (P>0.05). And also in growth parameters, A. filiculoides and formulated feed with 35% protein was not significantly different from each other (P<0.05). In blood factors, there was not observed any significant differences in Mean Corpuscular Hemoglobin Concentration (MCHC), White Blood Cell (WBCs), red blood corpuscular (RBCs), glucose, cholesterol and chortisol (P<0.05) between treatments. Also in body composition the highest lipid was observed in group fed with pelleted diet (25% percent protein) however, it had not significant difference to group fed with pelleted diet (35% percent protein) (P<0.05) and all treatments did not show any significant differences in moisture, protein and ash measurements among each other (P<0.05).