Study On Preparation Of Yoly Against Bovine Mycoplasma And Pasteurella Multocida Pneumoniae And Effect On Clinical Application

The calve pneumonia and arthritis,which caused by the mixed infection of BovineMycoplasma and Pasteurella multocida and it can lead to a large number of calves’ death andcause severe economic loss. There is no ideal vaccine to prevent these diseases effectively,and it is easy to develop resistance to antibiotics and the effect is not stable to antibacterial.The aim of this study is to prepare yolk antibodies against Bovine Mycoplasma andPasteurella multocida, and observe the effect of these yolk antibodies on clinical application,then provide new methods to prevent and treat the disease. The results were as follows:1.The preparation of hyperimmune egg yolk antibodies for against Bovine Mycoplasma:laying hens were first immune using Freund’s complete adjuvant vaccine, the dose is0.5mgfor each hen, and incomplete Freund’s adjuvant vaccine was used to strengthen immunity onthe15,30, and45th after first immune, and the dose is1mg,1.5mg,2mg for each henrespectively. Yolk antibody titers was detected by the method of indirect ELSA. The resultsshowed that: yolk antibody titer is constant increasing on the15th day after first immune andit reach highest titer1:128000on the60th day,and titer maintained more than30d, then itbegins to decline.2. The preparation of hyperimmune egg yolk antibodies for against Bovine Pasteurellamultocida: laying hens were first immune using Freund’s complete adjuvant vaccine, the doseis1.5billion for each hen. and incomplete Freund’s adjuvant vaccine was used to strengthenimmunity on the10,20, and30th after first immune, the dose is3billion for each hen, Yolkantibody titers was detected by the method of IHA. The results showed that: yolk antibodytiter is constant increasing from the3th week after first immune and reached the highesttiter(1:1024) on the7th week, the titer maintained for5weeks, then it began to decline.3. The preparation of bivalent hyperimmune IgY for against Bovine Mycoplasma andPasteurella multocida: compare the three methods of dilution water, chloroform extraction,Carrageenan to extracte IgY, the results showed that: the method of carrageenan combinedwith ammonium sulfate to extracte IgY can achieve a high yield at a short time, and it issimple to operate, it can be used as the preferred method to extract the yolk IgY antibodies.The IgY prepared with this method is safe and reliable based on the sterility testing andanimal safety studies.4. Clinical observation of bivalent hyperimmune egg yolk antibody: the calves areprevented and treated by gavage with different doses of egg yolk antibodies andintramuscular injection of different doses of IgY, the results showed that: the best preventioncapacity of bivalent yolk is to gavage antibodies20mL and intramuscular IgY3mL for eachcattle; the best therapeutic dose is to gavage antibodies40mL and intramuscular IgY4mL foreach cattle. If additional conjunction use florfenicol by intramuscular injection and tylosin byintravenous injection, the cure rate can reach more than80%.