Prevention and treatment of Newcastle disease in chickens

Chicken Newcastle disease is caused by a virus acute septic infectious disease, can occur all year round, especially in cold and climate change season multiple, all kinds of age of chickens can be infected, 20~60 days old chicken most susceptible to infection, mortality is also high, the main characteristics are breathing difficulties, nervous disorders, mucosal and serosa bleeding and necrosis, let's take a look at the chicken Newcastle disease prevention and control methods!

Epidemic Characteristics of Newcastle Disease

1. Newcastle disease can occur all year round, but it occurs frequently in spring and autumn. The incidence rate also depends on the management level of different seasons. If the chicken house ventilation is poor, ammonia concentration is high, the temperature fluctuates between high and low, feeding density is too large, it will make the chicken resistance decline, when there is Newcastle disease virulent strain can break out of the disease.

2. When Newcastle disease is prevalent in a flock of chickens, most chickens are in incubation period at the beginning, and the mortality rate will rise linearly within 4~6 days, and most of them are acute type.

3. Due to the effect of vaccine, most of them are atypical at present, sporadic and appear as mixed infection.

Clinical symptoms of Newcastle disease

1, the most acute type: more common in the early stages of the epidemic, often do not show characteristic symptoms and sudden death, more common in chickens.

2. Acute type: chicken body is hot in the early stage of disease, depressed spirit, decreased appetite, increased thirst, decreased egg production or production of laying hens, increased soft shell eggs, lighter eggshell color, and sometimes abnormal eggs. Then cough, breathing difficulties, mouth stretch neck breathing, often issued a strange cry. The crop is full, and the sick chicken is poured out with sour liquid from the mouth. Sick chicken diarrhea, discharge yellow-white or yellow-green loose feces, sometimes discharge albumin-like loose feces, and mixed with green. Some have neck tremors.

3, chronic type: to appear paralyzed chicken, head and neck backward or one side torsion, or soft neck more common, often accompanied by diarrhea, discharge yellow-white or yellow-green loose feces, sometimes discharge mixed with green egg white feces.

Treatment of Newcastle Disease

1, the first stage of disease: mostly in chicks 3~4 days of age when the disease. Head tremor and hemiplegia appeared in the early stage, and twisted neck and circular movement could be seen after 4~5 days. The typical lesion is bleeding point in small intestinal mucosa 1.5 cm behind yolk pedicle, which is of great significance for early diagnosis of Newcastle disease. As long as the chickens with symptoms are burned in time, the chickens shall be inoculated with Newcastle disease oil vaccine at the same time with twice the amount of live Newcastle disease vaccine. After inoculation, you can drink gold polysaccharide (Astragalus polysaccharide) to promote the development of immune system and induce antibody production.

2. The second stage of onset: most of them occur at the age of 19~21 days. At this time, the maternal antibody of chickens disappeared, and the peripheral antibody level produced after vaccination was still low, forming an immune blank period and being in a susceptible state. Therefore, as long as the chicken farm is located in the high incidence area of Newcastle disease, the personnel flow is frequent, the disinfection consciousness is poor, the possibility of chicken flock disease is large, the clinical symptoms are typical, the mortality rate is high, and it is difficult to control. Once the disease occurs, emergency vaccination should be carried out, but the emergency vaccination effect of Newcastle disease IV strain or clone 30 vaccine is poor.

① Scheme 1: Dissection of glandular stomach papilla bleeding, severe lymphoid follicle bleeding in 3 intestinal tracts (descending end of duodenum, 2 cm below yolk pedicle, initial end of ileum), clone 88 vaccine produced by German Roman Company or Israeli vH vaccine can be used for eye spot or injection, and immunity can be produced after 24 hours.

② Scheme 2:3 times of Xinweiling +1 dose of Newcastle disease nucleic acid solution A + normal saline, intramuscular injection after mixing, 0.15 ml/mouse, and then drinking water with Newcastle disease nucleic acid solution B 24 hours later. After 3 hours, it can be combined with astragalus polysaccharide + florfenicol drinking water, vitamins, electrolytes, probiotics and other mixed materials to improve the immunity of the body and prevent secondary infection.

3. The third stage of disease onset: most of them occur after 30 days of age. Often atypical, secondary infection, chicken performance for snoring, cough, paralysis, soft neck, discharge green feces, low casualty rate. Available interferon 3 times the amount of drinking water, for 2 days, at the same time with Gankang (coptis, scutellaria, phellodendron extract, etc.) 100 grams per bag of water 100 kg, concentrated drinking, for 4 days. When mixed infection occurs, Chuanzhi Granule (Flos Daturae, Ephedra, bitter almond and other traditional Chinese medicine preparations) and florfenicol can be used in combination.

Preventive measures against Newcastle disease

Environmental sanitation: Strengthen feeding management, reduce feeding density, do a good job of air disinfection in the house, and focus on improving the ventilation conditions of the chicken house.

2. Vaccination

① In general epidemic areas, the following immunization procedures can be adopted: 7 days old with Newcastle disease IV vaccine + live vaccine (H), nasal drops, simultaneous injection of new two-branch oil vaccine, 23 days old with Newcastle disease IV vaccine or clone 30 vaccine 3 times water, 33 days old with Newcastle disease clone 30 vaccine or IV vaccine 4 times water.

(2) In the areas seriously contaminated by Newcastle disease, spray or nose drop or eye drop with Newcastle disease and attenuated vaccine at 1 day old, drink water with Newcastle disease attenuated vaccine at 8-10 days old, subcutaneous injection of Newcastle disease oil vaccine at specified dose in neck, drink water with attenuated bursal disease vaccine at 14 days old, and drink water with Newcastle disease attenuated vaccine at 20 - 25 days old.

③ During vaccine immunization, the operation shall be careful. Eye spot and nose drop shall ensure that chickens are released after inhalation. The vaccine used shall be diluted and used immediately, and shall not be heated. It shall be used up within 30 minutes. Virus medicine, traditional Chinese medicine for clearing away heat and detoxifying shall not be used within 1 day before and after vaccine use. Antibiotics, electrolytic multivitamins or vitamin C shall not be used within 3 hours before and after vaccine use.

3. Strict disinfection

① Disinfection pool shall be set at the gate of farm and chicken house. Put some straw or straw mat in disinfection pool first, and then pour disinfectant solution. Disinfectant solution can be 2%~3% sodium hydroxide or 5% lysol, the injection amount should be soaked in grass is appropriate. Change the disinfectant regularly once a day.

② Disinfect the chicken house once a week, and disinfect the surrounding environment of the chicken house and all kinds of breeding utensils. Disinfectant solution can be 2% sodium hydroxide, 3%~5% lysol, 0.2%~0.5% peracetic acid. However, chickens should not be disinfected for at least one day before and after immunization.

③ The chicken house should be strictly disinfected. It is better to empty the house for 2 weeks before entering the chick. For urgent use, open the doors and windows for ventilation for 24 hours after fumigation for 24 hours, and use them after there is no irritating smell.