Study On The Safety Evaluation And Application Effect Of A Swine Atrophic Rhinitis Vaccine In Pig Farms

AR is a chronic infectious disease of respiratory tract in pigs.It can be divided into two types: progressive and non-progressive.Pasteurella bronchiosepticus and Pasteurella multocida are recognized as one of the most important infectious diseases which seriously harm the production and development of intensive pig farms and have a serious impact on the pig industry at home and abroad.At present,the vaccination of swine atrophic rhinitis vaccine,strengthen the management to prevent the infection and transmission of the disease.Objective: A large-scale pig farm in Hunan Province studied the safety and practical application effects of inactivated vaccine for atrophic rhinitis in a pig in the market.Methods:In April 2017,an on-site investigation of a slaughterhouse was conducted to assess the infection of atrophic rhinitis in pigs of a large scale pig farm and to take immunization measures against the vaccine.The safety of the inactivated vaccine was evaluated with the blank unimmunized pigs and the economic benefit of the vaccine was analyzed.1.By comparing the incidence of the blank group and the immune group and according to the investigation of slaughtering site,the incidence of AR in a large scale pig farm was evaluated effectively.Second,the safety of the vaccine was studied.50 pregnant sows of similar age and growth were randomly selected and divided into two groups.The immunized group received the first immunization at 8~9 weeks before birth,while the blank group did not treat it.The body temperature before immunization was measured in blank group and immunized group,and the body temperature at 24 h or 48 h after immunization was measured,and the local and systemic responses of immunized sows and reproductive performance index of vaccinated sows were recorded,and the second immunization was carried out at 4~5 weeks before and after immunization.The treatment method and measurement index are same as above.Third,further study the economic benefits of the vaccine on the offspring of pregnant sows from the stage of conservation to fattening.299 piglets were randomly selected from the offspring of the immunized sows as immunization groups ?,?,respectively.276 piglets of unimmunized sows were randomly selected as blank group ?,?.The effects of the vaccine on the economic benefits of conservation were analyzed.The survival rate,daily gain,outage time and growth performance of each group were counted respectively.Results:1.By measuring the body temperature of pregnant sows in the immunized group and the blank group at 0h,6h,24 h and 48 h,all sow's body temperature was in the normal range;after immunization the sow's feed intake was normal and no side effects were observed,suggesting that the vaccine was safe and reliable,less stress to pregnant sows and no influence on sows' breeding index.2.The atrophic rhinitis vaccine not only has good safety,but also has an ideal clinical immune effect.Through random investigation of the 6 pigs in the blank group,the statistical analysis showed that 50% of pigs were mildly and moderately infected with the disease.After the immunization,9 pigs in the immunization group at the slaughter house were found that 77.78%(0 to 4 points)of pigs had slight lesions in the sternal ridges of the pigs and 22.22%(5 to 8 points)in the pigs had moderate lesions in the sternal ridges.It was confirmed that the use of the vaccine had a great effect on the improvement of the morbidity of the swine plague and could effectively improve the health of the herd.In addition,after immunization of pregnant sows,their descendants from the delivery room to the nursery stage to the fattening pig stage have effectively increased daily gains,survival rates,etc.,resulting in better economic benefits,reducing the immeasurable economy for the pig industry.Economic loss and the immune interference to other vaccines of the offspring piglets is not obvious,and it does not affect the normal vaccine immunity.Conclusion: the inactivated vaccine of atrophic rhinitis is safe and effective and can effectively improve the efficiency of production and reduce the economic loss of aquaculture.