Determination of enrofloxacin residue in the muscle and liver of cultured rainbow trout in Chaharmahal-va-Bakhtiary province by ELISA

Enrofloxacin is one of the broad-spectrum antibiotics in veterinary medicine which in recent years its application has grown considerably for the control of infectious diseases in farmed fish. The aim of this study was to quantify enrofloxacin residue in muscle and liver of rainbow trout cultured in Chaharmahalva- Bakhtiary province using ELISA method. For this, the samples were obtained from the farms located in Ardal and Koohrang areas during the spring and summer of 2011. Three farms were chosen from each area and 15 samples were taken from three weight categories including < 50, 50-150 and > 150 g 5 samples from each category). Results revealed that maximum (58.33) and minimum (23.33) percentage of enrofloxacin residue was determined in <50 g and >150 g categories, respectively. In Koohrang region, the quantity of enrofloxacin residues in muscle and liver samples was 13.84 ± 11.50 and 19.95 ± 18.06, respectively. Meanwhile in Ardal, the quantity of the residue was estimated at 12.83 ± 11.62 and 11.22 ± 11.09, respectively. Considering the sampling time, among spring samples the quantity of the residues in muscle and liver was estimated at 14.27 ± 13 and 22.06 ± 21.69, respectively. The quantity of enrofloxacin among the summer samples was 12.40 ± 10.29 and 8.86 ± 7.31, respectively. Moreover, mean value of enrofloxacin residue in the muscle and liver of Koohrang was higher than Ardal region. It was concluded that enrofloxacin residue was lower than the maximum acceptance limit determined by the European Union.