The effect of enrofloxacin, doxycycline and florfenicol on growth performance and survial of rainbow trout (Oncorynchus mykiss)

Abstract

Introduction: Antibiotic growth promoters have been banned in animal husbandry
and aquaculture in China, since 2020. Enrofloxacin, doxycycline and florfenicol are
the most used antibiotics in aquaculture for controlling various bacterial disease in
fish, although its effect on health of farmed fish remains a concern. In the present
study, rainbow trout (Oncorhynchus mykiss) were fed on diets supplemented with
antibiotics.
Materials & Methods: 720 fish divided into 4 groups including: T1 (control), T2
(enrofloxacin; 10 mg /kg body weight), T3 (doxycycline; 70 mg /kg body weight),
T4 (florfenicol; mg /kg body weight). Sampling was performed at 0 th, 10th, 20 th, 30
th days. Growth performance and survival of rainbow trout were evaluated.
Results: The results showed that enrofloxacin has less effect on reduction of growth
in rainbow trout. Side effects of enrofloxacin on growth parameters are more than
doxycycline and florfenicol. Compared to the other drugs, florfenicol has a negative
effect on fish natural growth.
Conclusion: None of the antibiotics that used acts as growth promoters in rainbow
trout.