Manufacture Of Freeze-dried Yolk Antibody Against Gosling Parvovirus

Goose plague is an acute or subacute septicemic infectious disease caused by goose parvovirus?GPV?.It is susceptible to goslings of 4 to 20 days old,with high morbidity and high mortality.In this paper,through the research on the manufacturing process,safety and efficacy of the freeze-dried Ig Y against gosling parvovirus,the research on regional test,the purpose is to lay the foundation for the industrial production of Ig Y.The prevention and treatment provides inexpensive green biologics.The experiment firstly screened the laying hens immunization program through 4 different immunization doses and interval time.Octanoic acid,acidified water dilution,citric acid sedimentation and acidified water dilution-octanoic acid method were used to screen the ways of isolation and extraction of Ig Y.From three groups of different components and proportions of trehalose,sucrose,mannitol and glycine,Screening the protective agent and freeze-drying technology of yolk antibody.The inactivation process of yolk antibody was screened by pasteurization,formaldehyde inactivation and ⁶⁰Co irradiation.Three batches of the freeze-dried Ig Y against gosling parvovirus were produced according to the optimized production process,and their properties,sterility,mycoplasma,exogenous virus,vacuum degree and residual moisture were tested.The safety of the freeze-dried Ig Y against gosling parvovirus was evaluated by single-dose repeated injection,over-dose injection,and non-target mice injection.The relationship between the antibody titer and the challenge protection,the minimum preventive dose,the minimum protective dose,and the passive the efficacy of the freeze-dried Ig Y against gosling parvovirus was evaluated by an immunoprotection period and the like.In order to further verify the safety and efficacy of clinical application of the freeze-dried Ig Y against gosling parvovirus,a batch test was conducted on 5batches of the freeze-dried Ig Y against gosling parvovirus produced in the regionally test.The results showed that the healthy laying hens were vaccinated with 0.5 ml/only,and the second booster vaccination was carried out 21 days after the vaccination,2.0 ml/only,and the third booster vaccination was carried out 21 days after the booster vaccination,2.0 ml/only.After 14 to 21 days after intensive inoculation,the egg agar expansion antibody titer can reach 1:32 or above,which can be used for the extraction of Ig Y.According to the experimental optimization results,the separation and extraction of Ig Y using acidified water?p H 5.0?-octanoic acid?0.2%?method for extracting high-free yolk;extracted high-yellow egg yolk using trehalose 3.0%,mannitol 1.0%,glycine 0.5%as lyoprotectant,freeze-drying time is 32 hours,good thermal stability;use 12k Gy dose the ⁶⁰Co irradiation inactivates the Ig Y,which can effectively kill the foreign pathogenic microorganisms.Three batches of the freeze-dried Ig Y against gosling parvovirus were produced according to the determined production process of the freeze-dried Ig Y against gosling parvovirus.All the test results were all qualified.The three batches of antibody titers were 1:16.The results of safety tests for overdose injection and non-target animal mice were safe.The prepared 3 batches of he freeze-dried Ig Y against gosling parvovirus has a positive correlation with the challenge protection;the minimum preventive dose of1-3 days old goslings are 0.5ml/only,the protection rate is 90%-100%,4 days old or older goslings are1.0ml/only,the protection rate is 100%;the therapeutic dose is 1.0ml for each goose without clinical symptoms,the cure rate is 100%,and the mildly diseased goslings each 1.5ml,cure rate it was 85.7%,which was ineffective for severely diseased goslings;the passive immune protection period of the freeze-dried Ig Y against gosling parvovirus on goslings was 6 days.Five batches of the freeze-dried Ig Y against gosling parvovirus were used for regional test.The results of 1353 goslings were safe.The survival rate of 3 days and 5 days after immunization with a recommended dose was 88-100%and the serum positive conversion rate was 100%in 3737 goslings.The serum positive conversion rate is 100%.The therapeutic test was conducted on 790 goslings.The cure rate of goslings with no clinical symptoms in the same group was 100%,and the cure rate of mildly diseased goslings was 81.9%.There was no treatment effect on severe diseased goose.The production process of the freeze-dried Ig Y against gosling parvovirus established in the experiment is suitable for industrial production,and the freeze-dried Ig Y against gosling parvovirus developed is safe and effective.