The Research On Fulminant Bacterial Disease Prevention Of Channel Catfish In Cage Culturing

1,The water reservoir's net-cage cultured Channel Catfish bacterial disease is severity in Yichang and Jinmen of Hubei province from 2005 to 2006.The prevail season is from April to October and fastigium is July to August.The disease fish typical symptom is filled with blood in circa-eyeball and fin's portion.with leukasmus on parietal region,with abdominal distention,with anal orifice flare.Most of disease fish's liver and kidney show tumefaction,punctate hemorrhage and dissipated.Some diseased fish turns blurred-liver and earth-yellow liver.The stomach intestine is full of blood,and have no elasticity with no food.The dominant bacterial strain,designated as and Cj-1,Cj-2and Cj-3 was isolated from the of typical diseased Channel catfish,(Ictaluris punctatus,Ringnesque).After artificial celiac injection with the bacterial suspensions,the healthy fingerlings appeared the symptoms the same as those diseased fish in nature. strain Cj-1,Cj-2and Cj-3 was confirmed Aeromonas hydrophila by physiological biochemistry identification.2,All of the three strains were tested of drug sensitivity.The results showed that three strains had the resistance to broad spectrum bacteriophage namely ampicillin, penicillin,cephalexin,erythrocin et al,but had highly sensitivity to trimethoprim-sulfamethoxazole,oxytetracycline,vibramycin.At the same time,four general antibacterial,for example oxytetracycline,vibramycin,trimethoprim sulfamethoxazole were tested to the three strains in restraining and disinfecting.The result showed vibramycin has good effect,but the other two medicine have high MIC and MBC.3,By adding to quantitative bacillus subtilis,lactobacillus and photosynthetic bacteria which density were 1.0×10¹¹,5.0×10¹⁰,5.0×10¹⁰ CFU/kg to forage,the Channel catfish immunity which were leucocyte swallowing,muramidase and immunoprotection was tested.The result showed that the three advantage germs has notable effect to the three aspects.Three experiment groups have high pp at 6d,and the number respectively is 65.63%,59.49%,55.91%,but the control groups were in 35.26%-45.77%.The Channel catfish has resist to pathopoiesia bacteria by feeding the three advantage germs and the immunifaction proctection rate were 73%,63%å’Œ44%.Thing over economics and immunization effect,bacillus subtilis and lactobacillus are good advantage germ to Channel catfish.4,The monitor spots included the Chantiel Catfish Non-enviromental Damage Cultural Bases in the county of ChangYang,Yi Chang and TianHe Fishery Limited Company of Yi Du.The disease situation of the chantiel catfish which were cultivated in 500 cages in these districts was watched closely.Then,the effective plan to prevent and treat the chantiel catfish disease was determined through clinical experiments.Prevention plan:Daily Breeding,administer the forage mixed with bacillus subtilis (2.0×1011/kg forage) and Vc(5.0g/kg forage),once in two days;when the change of water temperatures exceeds 3℃,administer the forage which mixed SANHUANGFEN (5.0g/kg forage ) and yeast polysaccharide(5.0g/kg forage ) two days continuously;if the fish disease happened in the 1000m around,splash the chlorine dioxide to the whole pond,three days one time,three times continuously.Treatment plan:administer the forage mixed vibramycin(1.0g/kg forage), SANHUANGFAN(8.0g/kg forage) and Vc(10.0g/kg forage);once a day,five days continuously,splash the chlorine dioxide to the whole pond,three days one time,three times continuously.