Q&A on actual combat of swine disease prevention

1. Why has the incidence rate of swine disease become higher and higher in recent years?

(1) Effects of immunosuppressive diseases

Infection of porcine reproductive and respiratory syndrome (PRRS) virus and porcine circovirus leads to low immunity of pigs and poor immune response after vaccination. At the same time, it is easy to cause mixed infection and secondary infection of pigs.

(2) The existence of classical swine fever caused by SARS

The continuous infection and external detoxification of classical swine fever virus in pig herds have led to frequent outbreaks of atypical classical swine fever. Swine fever virus syndrome in sows causes immune tolerance and piglet swine fever in piglets.

(3) Excessive stress

Feeding is highly concentrated, pigs are frequently transported, and the site is seriously polluted.

(4) Incomplete and unbalanced feed nutrients

Mass utilization of inferior fish meal, meat meal, bone meal, blood meal and feather meal contaminated by bacteria and mold.

(5) Vaccine abuse

Inoculation of multiple vaccines at the same time, coupled with operational errors.

(6) The weaning time of piglets is unreasonable

The disease resistance is weak at early weaning, and there is no sufficient feeding before weaning, resulting in a high incidence of diarrhea.

(7) The method of insect repellent is not scientific, and the use of insect repellent drugs is improper.

(8) Poor awareness of disease prevention.

2. How harmful is swine fever?

Swine fever accounts for more than one third of the number of pigs killed by disease in our country. Zhang Jiazheng, Pig Raising, 2004, Issue 2.

Swine fever is the disease that causes the great economic loss of our country's pig industry. Wang Changjiang (Director of the Veterinary Department of the Department of Animal Husbandry and Veterinary Medicine of the Ministry of Agriculture) delivered a speech at the doctoral class of China Agricultural University in September 2003.

More than half of the number of pigs killed by disease in wo country is related to the infection of classical swine fever virus. Xie Qingge (Chief Scientist of the National Research Group on Major Epidemic Diseases of Livestock and Poultry) delivered a speech at the doctoral class of China Agricultural University in September 2003.

In production practice, there are indeed many pig diseases related to classical swine fever virus infection.

3. How to master swine fever?

(1) Range pig farms should use fluorescent antibody method to detect and eliminate recessively infected pigs and infected pigs.

(2) Formulate scientific and reasonable immunization procedures and earnestly implement them

Piglets: first immunization at 20 days of age, 450-600RID (3-4 doses of conventional vaccine)

55-day old secondary immunization, 600-750RID (conventional vaccine 4-5

Head portion)

Reserve sows: immunized with 750-900 RID 4 weeks before breeding

(5-6 doses of conventional vaccines)

Pregnant sows: immune to 900-1050RID during empty pregnancy (20 days postpartum)

(6-7 doses of conventional vaccines)

Pregnant sows: in principle, it is not allowed to vaccinate swine fever vaccine to avoid fetal pig infection

And cause immune tolerance of piglets.

Breeding boars: Inoculate every 4 months, 6-7 pigs per share.

(3) Regular disinfection

Select disinfectants with good effect on swine fever virus, such as Nongfu, Weikang, etc

Disinfection is required.

(4) Disinfection before immunization

Thorough disinfection must be carried out the day before inoculation of swine fever vaccine to avoid

Immune blank period infection.

(5) Immunization of piglets purchased in the market

After purchase, check for a week, and inject 5 doses of swine fever vaccine without any abnormality.

4. What is immune tolerance?

Immune tolerance refers to the fact that animals are not immune to the vaccine after being affected by specific factors

It produces immune response, but it can still occur after being infected by wild virus

Illness. For example, piglet embryos are infected or injected in the early pregnancy

The swine fever vaccine is inappropriate, and piglets have specific immune tolerance to swine fever virus,

Inoculation of classical swine fever vaccine does not produce immune response, but it encounters strong classical swine fever virus

Infection can cause disease.

5. What is super exemption? What are the advantages and disadvantages of swine fever superimmunity?

Superimmunity is the abbreviation of advanced immunity, also known as zero-time immunity. Is in

Piglets should be vaccinated before eating colostrum, and then eat colostrum every two hours

Immunization methods of milk. After scientific vaccination of breeding pigs,

It is better for newborn piglets not to be exempted from swine fever.

(1) Superimmunity delays the time for piglets to eat colostrum and affects the growth of pigs

development. Some experiments have shown that the piglets with the same litter and the same body weight do the superimmunity and

Compared with those who did not have a super immunity, they lost nearly 500 grams of weight at weaning.

(2) Preimmunization of newborn piglets can avoid maternal antibody

However, it is caused by the imperfect development of the immune system of newborn piglets

Immunity is not strong either.

(3) Superimmunity is a strong stress on piglets. From the point of view of reducing stress

It is better not to do it.

6. How to diagnose and treat atypical swine fever?

Atypical swine fever does not have the typical symptoms and pathological changes described in textbooks and atlases, thus causing difficulties in diagnosis.

And because the course of the disease is slightly longer and secondary bacterial infections (such as secondary swine pulmonary disease, piglet paratyphoid fever, actinobacter pleuropneumonia and haemophilus parasuis) occur, the change of bacterial diseases shows that the truth of the primary swine fever is concealed, causing difficulties in diagnosis and medication. Diagnosis of classical swine fever requires fluorescent antibody detection and enzyme-linked immunosorbent assay, but it cannot be done in pig farms and pig farmers. Through several years of clinical practice, the following experience is summarized for reference:

Those who meet the following four conditions at the same time can doubt the infection of classical swine fever

(1) Long-term high fever does not subside (persistent fever) above 41-42 ℃

Above, there is purulent discharge from the eyes.

(2) Antibiotics are ineffective after three days of continuous use.

(3) Patients with a longer course of disease appear in abdomen, ear tip, tail and nose

Cyanosis at the end and numbness in the back.

(4) Vaccination dose, vaccination time or vaccine itself of classical swine fever

Find out the problem.

Treatment:

(1) CSF serum injection

After serum injection, swine fever will be repeated 3 to 5 days after the symptoms disappear

Vaccination.

(2) Urgent vaccination of swine fever vaccine

Inoculation dose is 15-25 pieces, which can be based on the weight and disease of sick pigs

Distance selection. At the same time, it should be injected with immunoenhancer. vaccination

After 24 hours, the medicine can be applied according to the clinical symptoms without sticking to it.

Through more than three years of practice, thousands of cases have been treated clinically with the following results:

The cure rate can reach 85% for 0-3 days.

The cure rate can reach 70% after 4-7 days.

The cure rate can reach 50% when the disease occurs for more than 8 days.

The treatment effect of atypical swine fever mainly depends on early diagnosis and treatment,

The effect is better when there is no secondary infection.

7. Why does swine fever still occur after vaccination?

(1) Inadequate vaccine dose leads to inaccurate immune effect

Real. According to the European Pharmacopoeia, the amount of intramuscular injection is 400RID

(RID is the reaction volume of rabbit body), while each share of Wo is 150RID.

(2) The immunization program is unreasonable, resulting in an immune blank period.

(3) Presentation of swine fever virulent strains.

(4) Effects of immune suppression diseases, such as circovirus infection, pigs

Breeding and respiratory syndrome (blue ear disease) virus infection.

(5) Chronic infection and continuous infection of pigs carry and detoxify for a long time.

(6) Pregnant sows are infected with wild virus, causing disease or emergence of piglets

Immune tolerance.

(7) Incorrect operation during immunization.

(8) Feed is contaminated by mycotoxin.

(9) Use of immunosuppressants.

(10) Drugs that affect antibody production are added to the feed for a long time,

Such as tetracycline drugs.

8. How does swine infectious disease come into being? How to prevent it?

There are three conditions for the occurrence of infectious diseases:

(1) Infectious agent

Sick animals or animals carrying pathogens can continuously discharge pathogenic microorganisms to the outside world, which is called the source of infection. If the swine fever virus is continuously discharged from the infected pigs to the outside world, the infected pigs are the infectious source of swine fever.

(2) Spreading path

Pathogenic microorganisms discharged from infectious sources into the outside world invade easily moved objects through air, feed, drinking water, droplets, and dust to cause disease. This path is called the path of transmission.

(3) Susceptible animal

After the pathogenic microorganism invades the animal body, it causes the animal infection and disease, and this animal is called the susceptible animal of the pathogenic microorganism. For example, pigs are susceptible to swine fever virus.

The prevention of infectious diseases starts from these three aspects:

(1) For the source of infection

The source of infection can be eliminated by isolating, breeding, killing, eliminating, or curing the animals that are sick or carrying pathogenic microorganisms.

(2) For communication channels

Cutting off the path of transmission is a good measure to prevent infectious diseases. Disinfection and preventive dosing are to cut off the path of transmission.

(3) For susceptible animals

Immunizing animals to develop strong immunity turns susceptible animals into non susceptible animals.

To sum up, cure, eliminate, kill and isolate sick pigs; Disinfection and preventive dosing shall be carried out regularly; Immunization is the main means to master and prevent the occurrence of infectious diseases. In addition, the implementation of "all in and all out", the reduction of breeding density and the improvement of environmental control are all necessary means to prevent infectious diseases.

9. What is a vaccine? What is a vaccine?

Vaccine is a kind of biological drug produced by special process. It will produce corresponding immune response when inoculated into animals, so that animals have the ability to resist the disease. If swine fever vaccine is inoculated to pigs, it will produce resistance to swine fever virus, and it will no longer infect and attack when encountering swine fever virus.

Broad vaccines include vaccines produced by viruses, vaccines produced by bacteria, and mycoplasma vaccines produced by mycoplasma.

Vaccines produced by bacteria are called vaccine.

10. What is serum?

Serum is a component of blood and a liquid component of blood after centrifugation or coagulation. The important components of serum are immunoglobulin and serum albumin.

We usually say that the serum is the material that can prevent and treat the infectious disease after the animal is vaccinated artificially and purposefully, or the animal is naturally infected with a certain infectious disease and recovered. For example, swine fever serum can prevent and treat swine fever.

11. What is antitoxin? What is toxoid?

Antitoxin is a special serum.

Toxoid is a special vaccine.

Some pathogenic microorganisms do not produce pathogenic effects by themselves, but by the exotoxin produced by them.

Exotoxin is a special protein with antigenicity. In order to prevent and control the disease, the exotoxin produced by pathogenic microorganism is attenuated and then made into vaccine. This vaccine is called toxoid. Animals will be immunized with toxoid, and the animals will produce specific antibodies to it, which is called antitoxin. Such as tetanus antitoxin.

12. How to treat the role of vaccination in disease prevention?

(1) WY method: Vaccination is the WY method to prevent the disease, and there is no other way. Viral infectious diseases such as swine fever, porcine parvovirus disease, porcine pseudorabies, swine encephalitis B, and foot and mouth disease.

(2) Main measures: vaccination plays a major role in preventing the disease. For example, some bacterial infectious diseases with great persecution.

(3) Helping wrist: Vaccination helps prevent the disease.

(4) Secondary method: vaccination plays a small role in preventing the disease or the effect of vaccination is not good.

At present, the incidence rate and mortality of pigs are very high, which has something to do with vaccination. There are dozens of vaccines for pigs. We must understand what should be done and what should not be done. As the viral vaccine of WY manipulation, it is necessary to do a good job, and as the vaccine of the main wrist, it should be vaccinated as much as possible. Other vaccines Z should not be vaccinated, but should be prevented by routine administration of broad-spectrum antibacterial drugs.

13. Why is foot-and-mouth disease difficult to prevent?

(1) Due to the diversity and variability of serotypes

There are seven serotypes of foot-and-mouth disease, type O, type A, type C, type I of South Africa, type II of South Africa, type III of South Africa and type I of Asia.

Seven serotypes, including 65 subtypes. There is no cross maintenance between serotypes, and the cross shielding power between serotypes varies greatly.

Serotypes are variable, and new subtypes emerge every year.

(2) Universality of host

Pigs, cattle and sheep are all susceptible to foot-and-mouth disease.

(3) The specificity of virus construction

Foot-and-mouth disease virus is an envelope free virus with strong resistance to the outside world, and is not sensitive to general disinfectants.

(4) Rapid transmission of virus

Foot-and-mouth disease virus can be transmitted through the air and infected through the respiratory and digestive tracts. It often causes epidemics and pandemics.

(5) Multiple parts detoxification of diseased animals

The sick animals can detoxify from sneeze, saliva, droplets, feces and urine, and can also detoxify from blister fluid, blister skin and milk.

14. Will foot-and-mouth disease vaccine have side effects?

Inoculation of any kind of vaccine will produce side effects, but the size of side effects is different. Vaccines are also drugs, which are relatively special drugs.

The side effect of foot-and-mouth disease vaccine is much greater than that of general vaccines. Inoculation of foot-and-mouth disease vaccine often causes loss of energy and decreased appetite in pigs. Some piglets may last for more than ten days, and some may experience miscarriage after inoculation in pregnant sows. Therefore, it is necessary to control the dose and method of inoculation, and sometimes it is necessary to inject them at different points.

Immunization with ordinary vaccines will generally affect the weight gain of one day, while vaccination with foot-and-mouth disease vaccine will affect the weight gain of 2-3 days.

15. Is purple pig ears blue ear disease?

Not necessarily.

Generally speaking, purple is called cyanosis. It is a pathological change caused by heart failure, blood circulation disturbance or blood oxygen carrying efficiency reduction, resulting in blood stasis on the body surface or at the end, low oxygen content and high carbon dioxide content in the blood. Local temperature in cyanotic areas decreases and metabolic function is weakened. In the late stage of septicemia and various diseases, purple ears often appear, such as classical swine fever, piglet paratyphoid fever and streptococcal infection.

Pig blue ear disease, the scientific name of which is porcine reproductive and respiratory syndrome, is caused by virus infection. It is characterized by severe reproductive disorders in sows and pneumonia in young piglets, and purple ears is only one of the symptoms of this disease.

16. What is the difference between attenuated lyophilized vaccine and inactivated vaccine?

(1) The attenuated lyophilized vaccine is a live pathogenic microorganism with low toxicity, while the inactivated vaccine is a dead pathogenic microorganism with no toxicity.

(2) After inoculation of the attenuated vaccine, its pathogenic microorganism will replicate and proliferate in the body and stimulate the body to produce antibodies. The inactivated vaccine does not need and cannot replicate and proliferate in the body.

(3) The attenuated live vaccine can stimulate both the cellular immunity and humoral immunity of the body; Inactivated vaccines have poor ability to stimulate the body to produce cellular immunity.

(4) The attenuated live vaccine stimulates the body to produce antibodies quickly and for a short time. Inactivated vaccines stimulate the body to produce antibodies slowly and maintain a long time.

(5) The attenuated live vaccine generally adopts the vacuum freeze-drying process, and the inactivated vaccine does not need to be kept in vacuum, but the adjuvant used has a great impact on the immune effect of the vaccine.

(6) The attenuated vaccine usually needs to be preserved by freezing, and the inactivated vaccine (oil adjuvant vaccine) is generally preserved by freezing.

(7) The attenuated vaccine can be vaccinated by various methods such as eye drops, nose drops, oral administration, drinking water, and injection. Oil adjuvant inactivated vaccines can generally only be immunized by injection.

17. Which vaccines should be vaccinated for breeding pigs? How about the immunization program?

Breeding pigs must be vaccinated with four kinds of vaccines, including swine fever, pseudorabies, parvovirus and Japanese encephalitis, which seriously cause infectious breeding disorders and foot-and-mouth disease vaccine. Other vaccines such as swine erysipelas, swine lung disease, infectious gastroenteritis and epidemic diarrhea depend on the specific situation of the pig farm.

The immunization procedure is:

Swine fever: Reserve sows and boars are immunized once 4 weeks before breeding, with 5-6 pigs per share. Pregnant sows are immunized once 2 weeks before each breeding, with 6-7 pigs per share. The breeding boar is immunized four times a year, five pigs.

Pseudorabies: reserve sows and boars shall be immunized once three weeks before breeding. Pregnant sows were immunized once three weeks before delivery. Breeding boars are immunized 3-4 times a year.

Parvovirus: reserve sows and boars shall be immunized once a month before breeding. If necessary, pregnant sows should be immunized once three weeks before breeding. A pig can be immunized for life by continuous immunization for three times. Breeding boars can be immunized once every six months, and no longer after three times.

Japanese encephalitis: immunize once at the end of April every year, and continue to immunize for three years.

Foot-and-mouth disease: every September and January