Flumequine (Flu) is a powerful antibacterial agents used against bacterial infectiuons in fish farming because of their high potency against Gram- negative bacteria. The present work aimed to study the effect of different doses of Flumequine (0, 6, 8, 10, 12 mg during 90 days and 12 mg therapeutic s=dose for 5 days) on growth performance, feed untilization, body composition, chromosomal aberrations and determination of Flumequine residues in tissues of the tilapia fish. The results revealed that the dose of 10 mg/ kg body weight/ day caused significant increase in final body weight, weight gain, specific growth rate and feed intake. Moreover, it improved feed conversion ratio with the same dose whereas the other doses caused non- significant change in feed conversation ratio compared with control group. Also, the best protein efficiency ratio (1.95) was recorded by fish fed the diet with 10 mg/ kg body weight/ day. Results of proximate analysis of whole fidh body showed that the fish with dose 10 mg/ kg body weight/ day gained the highest percentage of protein and the loweat percentage of mositure, fat and ash. Determination of Flumequine residues in muscle of fish at the end of the experiment after three month showed negative results.
Flumequine at dose of 10 mg/ kg body weight/ day caused the lowest percentage in total chromosomal aberrations compared with the other dises that caused the highest percentage of total chromosomal aberration. In conclusion, this study recommended the addition of Flumequine to fish diets at a dose of 10 mg/ kg body weight/ day as prophylactic doose in order to increasse growth performance. feed utilization and decrease mortality of Nile tilapia.