Effect of prebiotic of Behsam on growth, feeding efficiency and and body composition of rainbow trout (Oncorhynchus mykiss) juvenile

To investigate the effect of dietary supplementation of Cell wall of Saccharomyces cerevisiae on growth performance and carcass composition of rainbow trout juvenile, an experiment was carried out on 600 pieces of Oncorhynchus mykiss with averaged mean weight 18±2 g for 45 days. This experiment conducted in a completely random design with four treatments which contain triplicates. Three levels of prebiotic (200, 400 and 600 mg.kg-1 of ration) were added to the basic diet. At the end of experiment it was observed that prebiotic supplementation at 200 and 600 mg.kg-1 in the diet caused increasing FW (75.91 and 74.16), FL (18.67 and 18.37), WG(57.91 and 56.16), LG(8.97 and 8.65), SGR(3.17 and 3.12), FCR(1.07 and 1.09), FCE (95.61 and 93.40), PER(2.12 and 2.07), LER(8.85 and 8.64), EER(0.056 and 0.055), as well as SGRP(3.21 and 3.22), SGRL(3.24 and 3.21) and SGRE(3.24 and 3.20) (p<0.05). The highest CVL (6.25) were absereved in treatment containing of 600 mg.kg-1 prebiotic (p<0.05). There were no significant (p>0.05) differences in CVW and CF of fish fed with the experimental and control diets. Whole body chemical composition of animals post-feeding revealed no any significant difference between treatment's (P>0.05). However, the highest Dry matter (30±0.28), Crude protein (19.48±0.83), Crude lipid (44.70±0.10) and Crude fiber (0.46±0.29) content were obsereved in treatment containing of 600 mg.kg-1 prebiotic supplemented diet. Finally, Based on these results feeding of rainbow trout juvenile on the diet supplemented with 200 and 600 mg.kg-1 diet caused improving growth performances and feed efficiency of Oncorhynchus mykiss juvenile.