Efficiency of dietary synbiotic on hematological, histopathological changes and resistance against Saprolegnia spp. in common carp, Cyprinus carpio L.

Abstract

This study was carried out to assess the efficiency of synbiotic on hematological, histopathological changes and resistance against Saprolegnia spp. in Cyprinus carpio. A total of 100 C. carpio weighing 49.55–50.50 g, were randomly stocked into five treatment groups. Fishes were fed different synbiotic concentrations: 0.5% (T1), 1.0% (T2), 1.5% (T3) and 2% (T4), as well as the control group (C) were fed basal diet without any addition of synbiotic. All treatments were fed twice a day at rate of 2% body weight for 56 days. At the end of the feeding trail, all the treatment groups were challenged in a viable fungal suspension of Saprolegnia spp. (1×105 live zoospores/ml). Considerable changes have been recorded in the differential leucocyte count, percentage of lymphocyte and monocyte showed significantly decrease (P