| Porcine mycoplasma pneumonia(MPS)is a chronic respiratory infectious disease in pigs.Its pathogen is Mycoplasma hyopneumoniae(Mhp).It is characterized by cough and asthma in the affected pigs.It is also known as swine asthma and causes pig breeding.One of the major infectious diseases of swine with severe economic losses.The prevention and control measures for the disease mainly through the application of antibacterial drugs and immunization of vaccines,but because Mhp is susceptible to drug resistance,the application of vaccine immunization is currently the main development direction of prevention and control of the disease.Most of the MPS vaccines used in the market are whole-cell vaccines,including live attenuated vaccines and inactivated vaccines.Among them,the inactivated vaccine is immunized by intramuscular injection,and the attenuated live vaccine requires injection through the chest,intrapulmonary injection,or intranasally.In our country,the swine mycoplasma pneumonia inactivated vaccine is mostly imported and the price is relatively expensive.The domestically developed inactivated vaccine products are mostly water-in-oil type and have poor safety;domestically developed and produced attenuated live vaccines have better immune effects.And the cost is relatively low,but some vaccine products need to be injected through the chest or lung injection,the operation is difficult,is not conducive to promotion.There are many kinds of commercially available swine mycoplasma pneumonia vaccines,and there are great differences in the immune effects among different vaccine products.How to choose a safe and reliable swine mycoplasma pneumonia vaccine is an urgent problem to be solved in pig farms.This study selected three vaccine companies’ four MPS vaccine products:Inactivated vaccine of company A,Inactivated vaccine of company B,Inactivated vaccine of company C,and live attenuated vaccine.Among them,companies A and B are foreign companies,and companies C are domestic companies.Fifty 10-day-old healthy piglets were selected.Each group was divided into 5 groups.The corresponding vaccine products were immunized according to the vaccine instructions:Group A(activated vaccine of company A),group B(activated vaccine of company B),and group C(Live vaccine of company C),group D(co-immunization of inactivated vaccine and live vaccine of company C),group E(blank control group).On the day of immunization,the overall status of the herd was observed.Then,at the 3rd,30 th,and 90 th days after the immunization,5 heads wererandomly selected from each group for nasal swabs and blood collection.Respiratory tract pathogen detection,stress-related hormone levels and related tests were performed.Disease detection of antibodies.When the pigs were slaughtered,the blood and lungs were collected again for Mhp pathogen detection,antibody detection,lung eye-view lesion scores,and microscopic examination scores.The test results showed that:The average weight gain of each group of pigs was compared.Among them,group D had the highest weight gain,the average daily gain was 0.615 Kg,and the average weight of slaughter was 110.663 Kg.The weight gain of group A and the blank control group was the lowest.The daily gains were 0.509 Kg and 0.506 Kg,respectively,and the average slaughter weights were 91.618 Kg and 91.06 Kg,respectively;Creatine kinase(CK),lactate dehydrogenase(LDH)and cortisol hormone(COR).When stress-related hormone levels were measured,it was found that the stress-related hormones produced in group B were lower and the response to stress was lower in pigs.The stress-related hormones produced in group D were higher and the stress response to pigs was higher.Larger.However,from the overall situation of the pigs,there was no obvious abnormality in the mental state,feed intake,and water intake of the pigs after immunization with each group of vaccines,indicating that each group of vaccine immunization produced only minor immune stress response to the pigs;The detection of Mhp pathogens showed that the positive rate in group B,C and D was 28.57%,the positive rate in group A and blank group was higher,50%;The level of Mhp antibody was tested.The detection rate was higher in group C and D than in group D.The antibody level in group D was highest,and no antibody was produced in group A;The score of the lung ocular lesions was the lowest in group D,which was 32.49%.The lesions in group A and blank group The degree was higher,which was 45%and 47.25%respectively;The scores of lung microscopic examination showed that the lesions in group D were the lowest with a score of 38 points.The lesions in group A and blank group were higher,with 56 points and 59 points respectively;6)Respiratory tract pathogen detection,mainly for infectious pleuropneumonia(APP),Haemophilus parasuis(HPS),and porcine pulmonary epidemic(PM)bacteria,the results are only detected 30 days after the vaccine immunization Positive to HPS,other pathogens are negative at other stages;Serum collected at each stage At the same time,antibody detection of CSFV,PRRSV,PRVg E,and PCV2 was performed to analyze whether the immunization of Mhp vaccine would have an impact on the immunity of other vaccines.The results showed that there was no significant difference in the average antibody level of each group at each stage,indicating that Mhp vaccine immunization had no significant effect on the immunity of CSFV,PRRSV,PRVg E,PCV2 vaccine;Comprehensive test results showed that pigs in group D had the best growth status,with the highest average pig weight gain,lower Mhp infection rate,higher levels of specific antibodies,and a smaller degree of lung lesions,suggesting the inactivation of porcine mycoplasma pneumonia.The effect of mixed immunization with seedlings and attenuated live vaccines was the best;followed by the attenuated live vaccine of company C;and the immune effect of attenuated vaccine against Mycoplasma hominis pneumoniae of company B was poor;and the immune effect of the inactivated vaccine against Mycoplasma pneumoniae pneumonia of company A was the worst. |
PDF Full Text Request