Luận văn Ảnh hưởng của sự nhiễm vi khuẩn Edwardsiella ictaluri và thuốc trừ sâu Cyrus lên sự thay đổi một số chỉ tiêu huyết học cá Tra (Pangasianodon hypophthalmus)

The aim of this study was to investigate the effects of pesticide and bacteria on hematological parameters of Tra fish. There was 2 experiments: the first experiment was randomly designed with 2 different concentrations of cypermethrin (LD 50-96 hours and 1/2 LD 50 -96 hours) and control. The second experiment were infected with bacteria Edwardsiella ictaluri on Tra fish. The result showed cypermethrin was highly toxic to Tra fish (LC50-96h is 3,89 mg/L). The erythrocyte quantity and hematocrit value decreased after administration of cypermethrin. MCV, MCH and MCHC were changed lightly and non-significant with control. Results from haematological analysis evealed a significant reduction in total number red blood cell in infected striped catfish (ranged from 1,4-1,51 milion cells/mm 3 ) compared to the healthy one (1,85 milion cells/mm 3 ). The number of white blood cell in infectedstriped catfish ranged from 14,94-16,02 thousand cells/mm 3 which was signficant lower than the number of white cells in health striped catfish(18,08 thousand cells/mm 3 ). Of these, the number of lymphocyte and thrombocyte decreased but the monocyte and neutrophil increased. Results from this study provide valuable basic information for further applied study diagnosis, and effective method for antibacterial in striped catfish farming.