The domestic swine fever virus C strain was purified by USA, Japan, local swine fever, but the domestic swine fever epidemic is still serious. Control of classical swine fever, the industry has different views, many people think is the problem of classical swine fever vaccine, and supervision of Chinese Veterinary Medicine (hereinafter referred to as the prison) researcher Gonin P is of the view that, classical swine fever epidemic and domestic in recent years large-scale introduction of a certain relationship.
The introduction and the same trend with the infection rate of swine
Classical swine fever is a kind of disease in China, from the beginning of 2007 national mandatory immunization requirements, normal immunization rate in more than 90%. However, even if the state is free to distribute vaccine mandatory immunization, swine fever control in many parts of China is still not optimistic. According to the prison of the monitoring results show that domestic hog cholera antibody qualified rate of 60%, susceptible herd number accounted for 40% of the total amount of feeding.
Gonin P, from 2000 to 2010 years in prison the 18 provinces 145 large-scale pig farms 40026 head pig tonsils monitoring found that swine virus rate of 13.89%. This has a certain relationship with the introduction of a large number of species. Gonin P told the southern rural news reporter, in 2007 the outbreak of highly pathogenic blue ear disease, pig large area of death and in the sub healthy state, 2008 from the introduction of foreign steep rise to 11613 head is nearly 5 times in 2007, is since 2001 introduced most of the year.
It is understood that the introduction of the trend in recent years is more common, the number is still rising. Each year in China from Europe and the United States large imported swine embryos in vivo and pork products, in 2008 the number of imports of pork as high as 373340.6 tons. So the import of meat products to large-scale introduction and control of Swine Fever brings certain difficulties. According to Gonin P, from the point of view of recent years foreign classical swine fever epidemic situation, Germany, France, the Netherlands, Italy, and more than other European countries and South America, Brazil, Argentina are classical swine fever epidemic countries. Imports from these countries, pig pig semen embryo and pork products, may be brought into the country of classical swine fever virus.
Virus gene into 2
The continuous invasion of foreign viruses, to a certain extent, will allow the virus to change, such as gene mutation or recombination, in which the blue ear virus is the most active gene mutation. Classical swine fever virus will blue ear virus, infection and the occurrence of changes due to pressure? Genotype will not change the?
In this regard, de Ning told the southern rural news reporter, molecular epidemiological investigation showed that the popular classical swine fever virus genotypes in the event of a major change. Prison and other units of the gene sequence from 1979 to 2008 in an area of nearly 60 farm of domestic more than 440 copies of classical swine fever virus samples were found, at present domestic popular classical swine fever virus genotype mainly genotype 2, accounting for 74.66%, and genotype 1 only accounted for 25.34%.
In the 80's of last century, ~90 years, mainly in the domestic swine fever virus genotype 1, but the genotype 2 is dominant. According to Ning Yibao introduced in 2011 from the 9 provinces of the 53 strains of the virus gene assay showed that 53 strains of the virus are all 2 gene. It is understood, the domestic hog cholera lapinized virus (used in the production of vaccine strains) for genotype 1. Fortunately, the vaccine for all genotypes of wild virus epidemic of domestic swine fever can provide good immune protection. Ning Yibao said.
The prevention and control of swine fever on two points: one is to ensure that the pig does not infect swine fever virus, two is to strengthen all pig immunization. Experience has shown that pig without wild hog cholera virus cases in order to ensure the, if commercial pig population antibody positive rate remained at more than 85%, pig antibody positive rate reached 95%, swine fever can be effectively controlled.
Is generally believed that the classical swine fever is more serious pig and cultivation as the reserve pigs pig, zero vaccine immunization is necessary. According to different farms, we developed two kinds of immunization programs 0-35-70 three day old and two day old 30-70 times. Gonin P told the southern rural news reporter, the pig farms in recent years extensive use of proof, with the two kinds of immunization program can produce good immune protection, just with different emphasis. And of piglets bred as gilts, in order to prevent early infection, easy to build without infection of classical swine fever virus reserve in the breeding herd, recommend the use of 0-35-70 day old three times inoculation of immunization program.