the analysis of oxytetracycline residue in tissues of cultured rainbow trout (oncorhynchus mykiss)

Background: oxytetracycline (otc) is commonly used in aquaculture industry and has high potency against bacterial diseases. objectives: the present study aimed at examining the rate of oxytetracycline (otc) antibiotic residue in the tissues of cultured rainbow trout (oncorhynchus mykiss). methods: samples were taken randomly from the livers and fillets of 45 rainbow trout from 15 large aquaculture ponds inhamadan province, west of iran. the otc residue was measured using high performance liquid chromatography (hplc). data analysis was performed with spss (v.18) (mean and standard deviation), and man-whitney test was employed for statistical analysis. results: the results revealed that otc residue were 389 to 641 ppb in the livers and 175 to 295 ppb in the fillets, respectively. however, in 86.66% of the samples (liver and fillet) the amounts of otc residue was found to be higher than the maximum residue limits (mrls) in codex alimentarius commission, and 13.33% of the samples (liver and fillet) were within the standard range. analysis of input and output data using man-whitney test showed significant differences in liver and fillet (p < 0.05). conclusions: this research determined that the use of otc must be reduced to an acceptable level in aquaculture industry. also, antibiotic residue in rainbow trout must be controlled before their delivery to the market.