The effect of vitamin B6 on hematological indicator of rainbow trout (Oncorhynchus mykiss) exposed to diazinon

Diazinon organophosphate toxin by affecting on non-target organisms, cause changes in blood indicator count. The aim of this study was to evaluate the effect of vitamin B6 (pyridoxine) on the hematological indicators of rainbow trout (Oncorhynchus mykiss) in the treatment of diazinon toxicity. A total of 120 fish (75.31±0.24 g) were fed on a basal diet for 2 weeks to acclimatize the laboratory condition, then they were fed with diet containing B6 in 2 treatments of 5 and 10 mg B6 per kg of food and a control treatment (with commercial diet) for 3 weeks. Treatments of vitamin B6 were exposed to 0.12 mg/l diazinon toxic for 10 days. The hematological indicator was measured at the end of days 1, 5 and 10. The lowest RBC and MCH were observed in 5 mg B6-diazinon treatment compared to control (p<0.05). The effect of time on reduction of RBC was significant in all days (p<0.05). Indicators of RBC, HB, HCT, MCH and MCV and lymphocyte percentage on day 10 showed a higher amount compared to the fifth day (p<0.05). The fifth day showed the highest WBC relative to the first day (p<0.05). The results showed that vitamin B6 at the level of 10 mg was able to prevent the negative effects of diazinon on fish and show improved hematologic function, especially red blood cells, leukocytes and lymphocytes, by treating the toxin with increasing time during the tenth day.