Fish Nutrition Research Laboratory, National Institute of Oceanography and Fisheries (NIOF), Cairo, Egypt
Fish Diseases Research Laboratory, National Institute of Oceanography and Fisheries (NIOF), Cairo, Egypt
A 2 × 3 factorial experiment was designed to study the effect of sublethal toxicity of technical grade copperoxychloride, dietary vitamin E and their interactions on growth performance, some blood parameters, DNA fragmentation and histopathological lesions of Nile tilapia (Oreochromis niloticus). The 96 h LC50 of copperoxychloride was found to be 129.21 mg/l. Four hundred and fifty fingerlings with an average initial body weight ranged from 1.92 to 2.04 ± 0.11 g were randomly distributed equally in six treatments (T1–T6) with each of triplicates. T4, T5 and T6 were exposed to sublethal concentration 0.25 LC50 of copperoxychloride. Fish of T1, T2 and T3 fed diet supplemented with different levels of vitamin E (0, 1 and 2 g/kg diet), respectively. While fish of T4, T5 and T6 fed diet supplemented with different levels of vitamin E (0, 1 and 2 g/kg diet), respectively. At the end of the experiment (90 days) the results indicated that fish exposed to 0.25 LC50 of copperoxychloride and fed diet with normal level of vitamin E, showed significantly lower values (P < 0.01) of all growth and feed utilization parameters, white blood cells and immunoglobulin M, but they showed significantly increased (P < 0.05) values of alanine aminotransferase, aspartate aminotransferase, hematocrit, hemoglobin, uric acid and creatinine. Fish fed with varied concentrations of vitamin E neutralized the toxic effect of copperoxychloride as well as vitamin E, significantly lowered the hematological and biochemical response and enhanced the growth parameters and feed utilization. The toxic effect of copperoxychloride exposure and vitamin E feeding on histopathological alterations of liver and gill of the same studied fish will be taken in concern. The results showed improvement in samples treated with vitamin E. This study suggests that vitamin E can be effectively used to decrease the toxic effect of copperoxychloride on O. niloticus and its amelioration through dietary vitamin E supplementation.