In all swine diseases, swine fever has been the highest rate of infection and incidence in the world. At present, the incidence of swine fever in China has a certain diversity. The prevalence of swine fever shows the coexistence of typical swine fever and atypical swine fever, the coexistence of persistent infection and latent infection, and the coexistence of immune tolerance and toxin syndrome, and the age of onset. Obviously broaden; the way of epidemic prevention is also varied. The disease vaccine from the first virulent crystal violet inactivated vaccine to the current swine ademeidal rabbit attenuated freeze-dried vaccine vaccine effect is very satisfactory, many foreign countries have already rely on rabbit attenuated vaccine to eliminate the disease, but in our country control effect It is still hard to satisfy. Virus and epidemic features The swine fever virus is a living organism, it will not stay on a horizontal line forever, and weakens its original toxicity due to the in vitro or in vivo antibody pressure. Instead, attenuated virulence can also increase or restore the original virulence after subse- quent infection in susceptible individuals. Due to this situation, the current swine fever virus has formed virulent, intermediate, and attenuated forms at the same time. The initial area is stronger and the area with more frequent attacks is weaker. Among them, virulent strains regardless of the breed or age of pigs can cause morbidity and death of most swine; intermediate strains have an effect on infection due to their resistance, and may cause death after onset, but they also recover from infections; The infection is limited to the pigs with weak immunity. Although it is a bit immune, the pigs that can't stop the invasion of the virus can't die, live happily, and have long-term spread of the virus. Such attenuated strains are only for piglets or The fetus is more likely to cause illness and death, it is often found in pig farms or rural herds where the immune system is not sound, immune disorders are formed, and feeding is poor. The prevalence of swine fever has shifted from outbreaks to mild ones. The shift from general herds to focus on sow infections in breeding sows, latent infections, and infection of placenta in piglets is also caused by unreasonable immunity, and the symptoms are not typical , but continue to detoxify outside the body, scattered drugs, these poisoned sows are often overlooked, and become the most important source of infection. The piglets they produce also often develop placental infections or develop immune tolerance. In the event of a mutation in the environment, maternal antibodies are reduced and the disease is triggered. This is also the main reason for the current spontaneous infection of some swine farms and local swine fever. Some pig farms and herds in rural areas have inadequate immune systems. The seedlings are unclear and the epidemic prevention process has taken place, sometimes from time to time. Then during pregnancy, the fetus through the mother's virus and congenital infection, resulting in stillbirth; some newborn piglet is weak, especially difficult to raise; What is more, due to congenital infections produce immune tolerance, neither clinical symptoms, future injections The vaccine also does not produce an immune response. When the environment changes, swine fever occurs again, which brings great difficulties to prevention work. Clinical symptoms and pathological changes The latent period of swine fever is generally 5 days to 8 days. According to clinical symptoms and other characteristics, it can be divided into the most acute, acute, chronic and delayed type. Most acute type No obvious symptoms of sick pigs, before the onset of mental and diet are normal, sudden fever, above 41 °C, skin and visible mucosa with purpura, punctate or diffuse bleeding, nasal cavity, retinal hemorrhage, sick pigs usually come one day after onset Within a few days soon died. Acute type The sick pig's spirit is highly depressed, and the diet is greatly reduced or refuses to eat. The Xiza pile is crowded, the muscles tremble, and the coat is rough; the bow, the gait, and both eyes have sticky or purulent secretions. After the initial constipation, diarrhea, feces with cellulosic mucus or blood; pre-congestion of the skin, and then become a purplish color, and there are many small bleeding points to the most common parts of the limbs, abdomen, ears and perineum, boar inside the penis There are turbid, foul-smelling fluids, and the duration of disease is 10 days to 20 days. Chronic type At the beginning of the disease, the pig suffers from loss of appetite, mental fatigue, poor appetite, and elevated body temperature, usually between 40°C and 41°C, and does not fall for several weeks. Constipation and diarrhea alternate, hairy and dry, and the skin has purpura or necrosis.痂; abdomen contracture, walking weakness. Pregnant sows generally do not show symptoms, but the virus can be transmitted to the fetus through the placenta, causing stillbirth, premature birth and so on. The diseased pigs are increasingly wasted and often die in the late stages due to failure. The disease duration ranges from 1 month to 3 months and even 3 months or more. Late-onset Pigs congenitally infected with low virulent classical swine fever virus can be normal in the first few months after birth. Subsequent symptoms such as food deprivation, depression, conjunctivitis, dermatitis, diarrhoea and dyskinesia are common. The body temperature is generally normal and most pigs can only survive 6 Month ~ 9 months. Misconceptions In theory, the use of China's self-developed swine plague rabbit attenuated vaccine can effectively control the occurrence and prevalence of swine fever, but in recent years the phenomenon of immune failure has gradually increased. There are many reasons. Vaccine quality If some of the vaccines are not manufactured by regular manufacturers, or if the vaccines are delivered without strict inspection, the vaccines do not reach the required potency; in addition, the vaccine is not properly controlled during transport and storage, and the diluent contains active substances that affect the vaccines. Diluted vaccines that have not been consumed within the prescribed period of time or placed under high temperature conditions will reduce the potency of the vaccine and thus affect the immune effect. Mistakes in operation For example, the use of a vaccine that has lost vacuum or a vaccine that exceeds the expiration date, lax disinfection, and the spread of the latent virus can affect the immune effect of the vaccine. Since the late 1970s, the prevalence of swine fever has undergone major changes. The effect of vaccine immunity is usually based on the prevention of clinical infections. When this standard is applied, the immune antibody level of some pigs after immunization may not reach the level of prevention of subclinical infections. This group of pigs can often cause subclinical infections after infection. Although infected pigs do not have obvious symptoms, they live in their lifetime and are poisonous and toxic. They are the main hosts of swine fever virus. Moreover, because long-term use of such vaccines does not fully block the transmission route of swine fever virus, the wild swine fever virus remains and spreads at a low level, resulting in the presence of genetic mutations or recombination with wild virus. The chance of causing a return to virulence. On the other hand, the widespread use of attenuated vaccines has also led to mutations in swine fever virus. Due to the existence of the above factors, a common area of ​​swine fever can be formed, and the clinical symptoms are mainly mild swine fever. In addition to the above factors, there are also some infectious diseases, which can also increase the susceptibility of animal organisms to other pathogens, reduce the immune response to multiple vaccines, and even lead to immune failure. Some viruses directly invade pig lymphoid organs. And immune cells, induce the release of certain cytokines, activate inhibitory cells, and thus affect the immune effect. There are also some drugs that also affect the immune effect. Studies have shown that tetracycline, neomycin, streptomycin, kanamycin, tylosin, chlorogenic acid, glucocorticoids, and other drugs inhibit the formation of antibodies in animals. Effect or inhibition of T, B lymphocyte transformation significantly, the use of anti-viral drugs will directly damage the vaccine. Problems such as poor feeding and management and feed quality, such as moldy feed, insufficient or lack of nutrients, excessive stocking density, poor ventilation, high concentrations of harmful gases in the air, long-term stress, etc. all inhibit immune responses. Affects the production rate or number of immune antibodies, leading to immune lag or failure, which affects the immune effect. Prevention measures Rational selection of vaccines for prevention of well-selected vaccines: At present, there are two major types of vaccines for swine fever in China: the tissue freeze-dried vaccine (I) and the cell freeze-dried vaccine (II) because there is only one serotype and there is only a difference in virulence. Therefore, the most important thing to consider when choosing a swine fever vaccine is the antigen content of the vaccine and whether there is an allergic reaction. If you can guarantee the above two points, you can use it with confidence. Monitoring the status of herd antibodies The current mutual infection of various diseases makes it impossible to test the antibody level with past experience. In order to better understand the antibody level of the herd, the antibody level of the herd must be regularly Test and then set a reasonable immunization program. Proper immunization doses The widespread use of vaccines at present has made the immune pressure of swine herds excessive. At the same time, the widespread use of vaccines has also changed the living environment of the virus. The past immunization doses have been difficult to meet the current needs, so in order to achieve the desired immunity The effect must be to change the immunization dose and increase the immunization dose appropriately. Generally, for the out-purchased pigs (30 kilograms) should be more than 6 heads, for self-bred autotrophy should be determined based on the level of maternal antibody, generally more than 4 heads. In order to make the vaccine more effective, some immune-enhancing drugs such as swine transfer factor can be used together with the vaccine. Prevention of Immunosuppression Infection Currently, there are a wide variety of infectious diseases in our country's swine herds. There are not only many existing diseases, but also many new diseases introduced from abroad, such as blue ear disease, pseudorabies and swine flu, etc., and in recent years in China Eperythrozoonosis in pigs with a very high incidence of disease also has a certain influence on the immunity of pigs. Therefore, the prerequisite for reducing the incidence of swine fever is to control the occurrence of immunosuppressive diseases. There are many man-made factors in strengthening the feeding and management of swine fever in China. For example, if the awareness of pig farmers is backward, changing the current situation must be changed from the root cause. That is, advocate good anti-epidemic concepts and abandon that kind of preference. The idea of ​​spending more money when sick, but also institutionalizing the concept of epidemic prevention, many people only carry out epidemic prevention in case of onset or other diseases on the farm, and once they recover or the symptoms are not obvious, they will not be immune or change arbitrarily. Immunization time and dose. In short, only by fundamentally changing people's management concepts can we solve the problem fundamentally. In addition, due to the current market stimulus, many people only care about the interests and ignore the feeding and management of the pigs, which makes the pigs' living environment extremely harsh. This has become another important reason for the onset of swine herds and vaccine failure. At the same time, there are reasons for feed. At present, there are still many pig farmers raising pigs. Even if compound feed is used, it can be saved in terms of raw materials. It only cares about the cost and has little attention to the health of pigs, such as the application of mildew. Maize and so on, resulting in the pigs in a sub-health state, the resistance to the disease was significantly reduced. Therefore, farmers need to completely change this concept of breeding, to strengthen feeding and management to create a suitable living environment for the pigs, thereby reducing stress and improving the body's resistance to disease.
We provide the electronic ballast for different uv light.
Like the ballast for hot cathode uv light, ballast for colde cathode uv light, ballast for Amalgam Lamp,and ballast for PL UV Germicidal Lamp.
We could do 110V/220V, 50/60hz from 4Watts to 320Watt.
Electronic Ballast Electronic Ballast, Electronic Ballast for UV Lamp, Electronic Ballast for Amalgam Lamp Ningbo Sunfine UV lighting Co.,ltd. , http://www.uvlightings.com
Electronic Ballast