Study Of Caprine Clostridial Diseases Vaccine-Avermectin Combined Preparation

Animal epidemic diseases include infectious diseases and parasitoses,which are very harmful to animal husbandry.In the case of caprine or sheep,clostridial disease and gastrointestinal nematodiasis are often easyly prevalent.Clostridium disease,is characterized by acute incidence,short duration and high mortality,and the main measure for the prevention of the disease is immunization with the vaccine.Meanwhile,gastrointestinal nematodiasis which also seriously endangered ovine industry,are mainly controlled by avermectin and its ramificative drugs.At present,the prevention and treatment of these diseases are usually carried out separatly,which not only bring a lot of inconvenience and trouble to the owners,but also waste money and labour.Therefore,it will porobably be of great clinical practical significance to develop a combination of clostridial diseases vaccine and avermectin,which could be used to control clostridial disease and gastrointestinal nematodes at the same time.In this study,the diluent of vaccine were used to prepare avermectin emulsion in water,then the clostridial diseases vaccine-avermectin combined preparation were made.The related indexes of the preparation were detectived and evaluated.First of all,in order to ascertain the infection of sheep's gastrointestinal nematode,epidemiological survey on parasitoses was carried out in Wushenqi area of Inner Mongolia region.The results showed that the average infection rate of nematode eggs was 56.6%.The average EPG was 1089,and the maximum EPG was 14200.Secondly,the avarmectin emulsion in water were successfully prepared by screened single solvent,multiple solvent,combined emulsifier,antifreeze and thickener.Then,the qualities of combined preparation were tested and it met with the requirements.Thirdly,the toxicity of combined preparation,its irritation to the animal skin,serum avermectin content and clinical deworming efficiency have been done.The results indicted that the LD50 of the combined preparation was 12.75mg/kg.The skin irritation was light and there was no harm to the liver and kidneys of mice.The concentration of avermectin reached the peak after 24h administration,and the deworming effect was obvious,which also showed the effect of avermectin had not been affected by the vaccine and other chemical compounds.Finally,the immunological efficacy of the combined preparation to the clostridial disease was detected by serum neutralization test.The result revealed that the avermectin emulsion in water did not affect the immunogenicity of the vaccine.