Pathophysiological response and IL-1β gene expression of Labeo rohita (Hamilton, 1822) fingerlings fed with Oxytetracycline based pharmaceutical diet against Aeromonas hydrophila infection

Abstract

The present study was conducted to explicate the effect of oxytetracycline (OTC) based pharmaceutical diets on hematology and immuno-pathophysiological response and IL-1β gene expression in Labeo rohita fingerlings against Aeromonas hydrophila infection. The experiment was conducted in five groups (T1 to T5) for 40 days in circular 300 l tanks. T1, T2 and T3 group fishes were infected with A. hydrophila and fed with OTC based diet 55, 70 and 83 mg/kg body weight/day, respectively for 10 days (as per FDA standards) followed by normal diet for rest 30 days. T4 (NC-Negative Control) and T5 (PC- Positive Control) containing normal and infected fishes respectively, were fed with normal diet throughout the experimental period. The sampling was done on 0th, 10th, 20th, 30th, and 40th day of the feeding and various immunological, haematological, biochemical parameters and IL-1β gene expression were analysed. The best response was observed in the fish, fed with diet T3 within 20 days. The result showed a significant (p < 0.05) increase in haemoglobin, haematocrit, total RBC & WBC count, NBT, lysozyme activity and total protein whereas significant (p < 0.05) decrease in glucose, ALP, SGPT and SGOT level compared to NC. The T3 fishes showed significantly higher immune gene (IL-1β) expression in kidney and spleen. Hence, the study concludes that inclusion of OTC @ 83 mg/kg BW/day for 10 days in diet enhances the immune response and reduces the effect of A. hydrophila infection in L. rohita fingerlings.