Application Of A New Povidone Iodine Preparation In Aquaculture

Povidone iodine(PVP-I)also known as polyvinylpyrrolidone iodine,it is complex compound of iodine element and polyvinylpyrrolidone(PVP).It is an efficient broad-spectrum fungicide with characteristics of less stimulus,long-acting,no pollution and no residues.It is an ideal disinfectant for the water and animal in aquaculture.It can replace antibiotics and reduce environmental pollution.Povidone iodine has attracted great attention because of its excellent bactericidal ability,and with the improvement of processing technology,the safety of povidone iodine preparation has been greatly improved.Povidone iodine in aquaculture also has a wide range of applications,due to its excellent sterilization ability,mainly used for short immersion disinfection of water disinfection and animal,the most common usage is in water deterioration when pool splash,can quickly inhibit pathogen growth.Safety of povidone iodine to aquatic animal greatly affected by its processing quality,many studies showed that safety of povidone iodine in physianthropy better than it is in aquaculture.Due to the different quality of povidone iodine used by different researchers,the safety of povidone iodine is different.Therefore,it is urgent to improve the quality of povidone iodine preparations for aquatic products.In order to study the application value of a new povidone iodine preparation "Yu Duo Fu" in the aquaculture.The bactericidal concentration of povidone iodine against Streptococcus lactis,Vibrio parahaemolyticus and Vibrio parahaemolyticus was studied by in vitro germicidal test.We study the safety of povidone iodine to tilapia,catfish and litopenaeus vannamei and effect of prophylaxis and treatment through the feeding experiment.We study the effect of prophylaxis and treatment to acute hepatopancreas necrosis syndrome(AHNS)and the effect of physical and chemical properties to culture water through the full pool splash experiment.We study the toxicity of PVP-I on artemia cysts and nauplii and the effect of hatching rate of artemia cysts from three different regions and perform the disinfection experiment for artemia and water.The main results are as follows:1.With different concentrations of "Yu Duo Fu" treatment of 3 kinds of pathogenic bacteria for 20 min,the 20 ppm "Yu Duo Fu" kill all of v.mimicus,the 30 ppm "Yu Duo Fu" can kill all of v.parahaemolyticus and s.agalactiae,and bactericidal effect is remarkable.2.At a dose of 5000 ppm fed tilapia,catfish and shrimp for 5 days,stress and death were not found in the experimental animal,snatch and vigor were normal.Take tilapia and catfish's brain,liver,spleen and intestine,and litopenaeus vannamei's hepatopancreas and perform paraffin sections.No injury or necrosis was found in all the tissues,it proves that the oral safety of the fish is excellent.The "Yu Duo Fu" added to feed in three kinds of animal feeding,did not show better protection rate,cumulative mortality after infection of the control group and the experimental group have no difference,feeding that "Yu Duo Fu" and not very good control of three kinds of bacterial diseases.3.Full pool splash "Yu Duo Fu" for 2-3 days can significantly improve the situation of stealing dead shrimp.0.75 ppm per mu was slightly better than the effect of it on 0.37 ppm per mu.Ponds and cement pool pool splash "Yu Duo Fu",the nitrite,algae and planktonic animal was relatively stable,basically not affected by povidone iodine.The number of algae increased in the cement pond,suggesting that it may promote the growth of algae.The number of zooplankton in the cement pond did not change significantly,suggesting that the zooplankton was safe to the zooplankton.4.PVP-I have no influence on hatching rate of artemia cysts and do not cause nauplii death at high concentration(>20000 ppm)of soak for a long time.And we separate four advantages of bacteria(Vibrio tubiashii ? Vibrio sinaloensis ? Vibrio anguillarum and Uncultured Vibrio sp.)from artemia.Treatment with 500 ppm concentration of PVP-I for 30 min can kill almost all the bacteria in the water.And PVP-I have no influence on hatching rate of artemia cysts from Bohai Bay saline and Barkol saline within 2000 ppm concentration range but greater than or equal to 500 ppm concentration PVP-I significantly decrease hatching rate of artemia cysts from Russia.