Effect of silver nano particles on carcass composition of goldfish (Carassius auratus) pre-treated with Raffinose oligosaccharide and Pediococcus acidilactici bacteria

Aim of this study was to investigate the protective effect of pre-treatment of bacteria pediococcus acidilactici and oligosaccharideRaffinose on carcass composition of Goldfish (carassius auratus) in exposure to nano silver. Accordingly, 250 fish with an average weighing of 26.3±0.18 fed for 6 weeks in four treatments and each treatment with three replications including diet without food supplement (control 1), probiotic diet of bacteria with a concentration of 107 colonies per gram (treatment 2), food containing probiotic Raffinose (1 g/kg) and synbiotic (treatment 4). After the end of the feeding period, 50% of the nano-silver concentration (0.5 mg/L) was exposed to the treatments for 14 days and at the end of the 14-day exposure, carcass sampling was performed. At the end of the experiment, analysis of data showed that there was no significant difference in the moisture content, ash, protein and carcass fat among the treatments (P>0.05). However, in some indices, such as moisture, protein and ash, there were increased trend in synbiotic treatment, but this increase was not significant (P>0.05). Regarding the results of this study and the lack of meaning of relevant indices in these treatments, it seems that using studied supplements with this concentration does not had an appropriate effect on the studied indices.