Development And Immune Effect Evaluation Of The Inactivated Vaccine Against Mastitis For Dairy Goats

Goat mastitis often occurred during lactation period, and sometimes occurred in theprenatal and dry milk period. Presently, the subclinical mastits detection rate is high in China.The mastitis could not only reduce the milk production and milk quality and cause seriouseconomic losses, but also directly affects the function of dairy goats, and even killed the goats.It is the most harmful disease to breeding industry of dairy goats. Traditional antibiotictherapy not only led to a large number of resistant strains, but also bring serious food safetyhidden trouble, while, using vaccines to prevent and control the goat mastitis not only couldreduce the degree of mammary gland infection, but also could control the subclinical mastitis.Adjuvant is the key component of immune vaccine. Using of reasonable and effectiveadjuvant can enhance the immunogenicity of antigen, promote the immune response andenhance protective response of the host to antigen. In this study, the main pathogenicbacteria in goat mastitis, E.coli, Staphylococcus aureus, coagulase negative Staphylococcusepidermidis and Staphylococcus chromogenes were used as materials to make inactivatedvaccine. The adjuvant screening and evaluation of immune effect were also studied. Theresearch content and results are as follows:1. Development and immune effect evaluation of the inactivated vaccine aginstmastits for dairy goats.E.coli, Staphylococcus aureus, coagulase negative Staphylococcus epidermidis andStaphylococcus chromogenes were inactivated by using methanal at37℃and then thoroughlymixed with adjuvant aluminum hydroxide with a ratio of6:1(V/V). Each lactating dairy goatwas inoculated subcutaneously via neck or inguen twice with a interval of14d and the dosagewas2mL each time. Blood and milk samples were collected before and post inoculation onday10,24,60and180. The levels of antibodies were measured by indirect ELISA while thenumber of goats suffering subclinical mastitis was measured by a rapid diagnostic reagent.The results showed that antibodies against E.coli, Staphylococcus aureus, coagulase negativeStaphylococcus epidermidis and Staphylococcus chromogenes in blood and milk weresignificantly increased compared with control after the twice inoculations (P<0.05), and theantibodies could last long. The number of goats suffering subclinical mastitis of the neck andinguen inoculated groups was less than control group until the day180and60post inoculation respectively. In conclusion, the inactivated vaccine against mastitis developed inthis study could not only stimulate the body to produce high-level antibodies but also has asignificant therapeutic effect to subclinical mastitis.2. Effect of three adjuvant to the immune effect of inactivated vaccineThe inactivated bacteria were mixed with aluminium salt, propolis or transfer factor toprepare aluminium salt, propolis or transfer factor adjuvant vaccine. Each lactating dairy goatwas inoculated subcutaneously via neck twice with a interval of14d and the dosage was2mleach time. Blood and milk samples were collected before and10days after each inoculation.The levels of antibodies were measured by indirect ELISA while the number of goatssuffering subclinical mastitis was measured by a rapid diagnostic reagent. The results showedthat antibodies against E.coli, Staphylococcus aureus, coagulase negative Staphylococcusepidermidis and Staphylococcus chromogenes in blood and milk of aluminium group weresignificantly higher than control group(P<0.05), and aluminum group’s the antibodies levelswere highest with the transfer factor group and propolis group followed. Aluminum adjuvantvaccine can significantly reduce the detection rate of subclinical mastitis, and the rate wasdropped from60%before the immune to30%after the second injection. In conclusion,compared with propolis and transfer factor, aluminum adjuvant can stimulate the body toproduce stronger humoral immune response and has a significant therapeutic effect tosubclinical mastitis.Conclusion:1. The inactivated vaccine against mastitis developed in this studycould not only stimulate the body to produce high-level antibodies but also has a significanttherapeutic effect to subclinical mastitis.2. When the vaccine was inoculated via neck subcutaneously, it can significantlyreduce the detection rate of subclinical mastitis.3. Compared with transfer factor and propolis adjuvant vaccine, aluminiumadjuvant vaccine can significantly increase the antibodies levels against different pathogen,and reduce the detection rate of subclinical mastitis.