The Clinical Effect Of Chinese Medicine "Radix Extract" On Controlling Viremia Of PRRS

Porcine reproductive and respiratory syndrome(porcine reproductive and respiratory syndrome,PRRS)is caused by porcine reproductive and respiratory syndrome virus(porcine reproductive and respiratory syndrome virus,PRRSV).PRRS is an important infectious disease that is a major hazard to the respiratory and reproductive systems,commonly known as blue ear pig disease.It can induced in pregnant sows premature birth,abortion,fetal death,mummy and occur Intermittent pneumonia and severe viremia in pigs of all ages.At present,many farms have PRRSV latent infection.PRRS induced high mortality characteristics of animal infectious disease and the mixed infection was serious.Now the commonly used attenuated live vaccine and inactivated vaccine against swine vaccination,but it’s still exist a lot of pig farms.At present,farms commonly used Chinese medicine,antibiotics,lipids and other medicines for Disease Control after the outbreak of PRRS,and has got good effect.Antiviral of traditional Chinese medicine have developed rapidly in recent years.Radix Isatidis is one of the traditional Chinese medicine with better antiviral effect,its main ingredients are Radix Isatidis polysaccharide,indigo red,indigo and so on.In vitro cell experiments showed that Radix Isatidis has a protective effect on Marc-145 cells by 100%.In this study,Radix extract 5g per head every day with Mixture feeding,and the piglets were infected PRRSV with severe viremia,the compound prescription,antibiotics,lipid and blank control group were also set up in the experiment.Each group of 12 weaned piglets,the mortality of piglets were recorded each day,and piglet body temperature is measured every other day.Blood separation serum was collected on the day of medication,the day of withdrawal and 7 days and 14 days after withdrawal,the change of antibody and the change of PRRSV antigen in serum were determined,so as to evaluate the clinical control effect of Radix extract on PRRSV viremia.The results show that,the experimental pigs fed the Radix extract all survived,1-2 of the other medicines died,and 6 of the blank control group died.The result of body temperature measurement indicated that Radix extract has a better cooling effect.The result of antibody level test showed that The S/P value of antibody in piglets fed with Radix extract was still in the range of wild toxin infection but the overall rate was significantly lower than before the use of medicine.The blank control group still maintained a high level,and the antibody level fluctuated greatly.The content of antigen in serum was determined by fluorescence qRT-PCR.The results showed that the content of antigen in serum of piglets was decreased obviously after feeding Radix extract.In this study,we studied the control efficacy of the Radix extract Chinese medicine preparation with Radix Isatidis as the main ingredient in the control of weaning piglets infected with PRRSV,The aim of this study was to find a better method for controlling viremia after PRRSV infection,so as to provide reference for the clinical treatment of the disease.