عنوان مقاله [English]
The aim of present study was to evaluate the effect of different levels of symbiotic (Biominâ Imbo) on growth, survival, body composition and food cost of Caspian Roach (Rutilus frisii kutum) fry. This experiment conducted in a completely random design with four treatments which contain triplicates. Three levels of symbiotic (2 gr/kg, 4 gr/kg and 6 gr/kg of ration) (Biominâ Imbo) were added to the basic diet. Fish fry were fed by experimental diets thrice a day at 10% of body weight for 70 days. Kutum fry (average individual weight, 623±6 mg) were randomly distributed with density of 2 fish/l into twelve 100 liter fiberglass tanks. The results indicated that fry which had been fed on the basal diet showed lesser production efficiency comparison other treatments. Adding synbiotic to diet had positive significant effects on the growth factors (final weight, weight gain, specific growth rate, feed conversation ration, protein efficiency ratio, feed efficiency and daily feed intak). But food convertion ratio showed significant decreas. No significant difference in the condition factor was observed. Adding synbioic except protein has not significant difference in other body composition. Ultimately, when all variables was considered, synbiotic Biomin Imbo inclusion to diets leads to reduce significant incidence feed cost and increase significant profit index.